JP2002036466A - Soft transparent and antibacterial polyolefinic sheet and its bag product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soft transparent and antibacterial polyolefinic sheet having the same flexibility and surface glossiness as a soft PVC sheet and also having antibacterial properties. SOLUTION: The soft transparent and antibacterial polyolefinic sheet 1 is characterized in that internal haze is 5% or less, external haze is 3% or less, the total light transmissivity is 80% or more and tensile elastic modulus is 50-1,000 MPa and has a multilayered structure including polypropylene resin layers 11A and 11C and a polyolefinic resin layer 11B. An antibacterial agent is added to at least one of the surface layers 11A and 11C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft transparent antibacterial polyolefin-based sheet and a bag-made product thereof.

[0002]

BACKGROUND ART Conventionally, soft vinyl chloride sheets and films (hereinafter, referred to as soft PVC sheets and films) are excellent in glossiness and secondary workability (embossability, high-frequency fusion workability) and inexpensive. Therefore, it is used for various purposes (such as bag-making products).

[0003]

However, the soft P
VC has a problem that a plasticizer and a vinyl chloride monomer are likely to bleed out, and the sheet appearance may be deteriorated, sticky, and contents may be stained. Further, when the surface has printing toner, ink, or the like, there is a problem that these colors are transferred to the sheet. Furthermore, when incinerating PVC, it becomes a source of harmful substances such as hydrogen chloride gas and dioxin, and may pollute the environment.

In order to solve such problems, soft PV
Various studies have been made on soft sheets using resins other than C. So far, polyethylene-based sheets (JP-A-5-30979 and JP-A-5-229082) and polypropylene-based sheets (JP-A-6-29082) have been described. 2188
No. 92, Japanese Unexamined Patent Publication No. 7-171849) and the like have been proposed. However, polyethylene-based sheets are
There is a problem that the surface gloss and the stiffness are inferior to soft PVC. On the other hand, polypropylene-based sheets are similar to soft PVC in mechanical properties such as rigidity and strength, and are excellent in embrittlement temperature, but have a problem of poor surface gloss.

[0005] On the other hand, recently, in addition to the growing desire for cleanliness,
Infectious diseases caused by pathogenic Escherichia coli O-157, Legionella bacteria in a 24-hour bath, and MRSA which is a causative agent of nosocomial infection have become social problems. Against this background, antimicrobial products to which an antimicrobial agent has been added have been spotlighted, and their demand is increasing.

An object of the present invention is to provide a soft transparent antibacterial polyolefin-based sheet having the same flexibility and surface gloss as a soft PVC sheet and also having antibacterial properties, and a bag-made product thereof. .

[0007]

The soft transparent antibacterial polyolefin sheet according to the present invention has an internal haze of 5% or less.
It has an external haze of 3% or less, a total light transmission of 80% or more, a tensile modulus of 50 to 1000 MPa, a multilayer structure including a polypropylene resin layer and a polyolefin resin layer, and at least one of its surface layers. It is characterized by adding an antibacterial agent.

As the antibacterial agent in the present invention, various known antibacterial agents such as inorganic (excluding silver), silver, and organic can be used. Preferably, it is used. Further, such a silver-based antibacterial agent is preferably used in a form supported on a carrier such as glass. By adopting a supported form, elution of silver ions exhibiting antibacterial properties can be prevented, and the antibacterial effect can be maintained for a long time.

Here, as the inorganic antibacterial agent, antibacterial glass, inorganic fine particles and antibacterial metal (copper, zinc, titanium oxide, etc.), amino acid metal soap, inorganic antibacterial gel based on porous silica gel, and the like can be used. . Silver antibacterial agents include silver antibacterial agents supported on potassium titanate whiskers,
Zeolite-silver antibacterial agent, antibacterial agent obtained by kneading silver ions into glass fine particles and treating the glass surface with fine particles, antibacterial agent of a mixture of calcium phosphate and silver, artificial zeolite-silver antibacterial agent, zirconium phosphate-silver-based An antibacterial agent, a silver-based antibacterial agent supported on silica gel, a silicate-supported silver-based antibacterial agent, and the like can be used. As the organic antibacterial agent, a compound obtained by intercalating a poorly soluble phosphate and an organic antibacterial agent (alcohol, surfactant, etc.) can be employed.

The antimicrobial agent may be added to at least one of the surface layers of the sheet having a multilayer structure. However, in order to exhibit antimicrobial properties on both sides of the sheet, it is preferable to add both of the surface layers. When adding an antibacterial agent, a predetermined amount may be added to the raw material resin, melt-kneaded, and then formed into a sheet. It is also possible to employ a method in which an antibacterial agent is blended in advance with a raw material resin or another resin, melt-kneaded, extruded and made into a master batch, blended with the raw material resin and formed into a sheet. The amount of the antibacterial agent added
It can be set appropriately according to the intended use of the obtained sheet.

In the present invention, if the total light transmittance is less than 80%, transparency is undesirably reduced. Further, if the internal haze exceeds 5%, the transparency of the sheet is undesirably reduced. Preferably, the internal haze is 4% or less. Further, if the external haze exceeds 3%, the transparency is undesirably reduced. If the tensile modulus is less than 50 MPa, the sheet becomes too soft and the strength is insufficient. On the other hand, if it exceeds 1000 MPa, the sheet is too stiff (insufficient flexibility) and the secondary workability is insufficient. Gets worse. Preferably, it is 50 to 500 MPa, more preferably 50 to 500 MPa.
３００300 MPa.

The glossiness of the soft transparent antibacterial polyolefin sheet is not particularly limited, but is preferably 100% or more in consideration of the sheet surface appearance and the like. When the glossiness is less than 100%, the surface appearance is inferior and the merchantability may be reduced. In consideration of further increasing the commercial value, the glossiness is preferably 110% or more, more preferably 120% or more.

In the present invention, the number of layers in the multilayer structure is not particularly limited as long as it is two or more layers, but is preferably a two- to ten-layer structure, more preferably a three- to nine-layer structure, and even more preferably a three- to five-layer structure. Structure. Further, it is preferable that the surface layer of the multilayer structure is composed of a polypropylene resin layer. In particular, it is preferable to adopt a three-layer structure composed of a polypropylene-based resin layer / polyolefin-based resin layer / polypropylene-based resin layer, and by adopting such a three-layer structure, a sheet having appropriate flexibility and strength. It can be. The layer ratio of each layer is not particularly limited, but is preferably in the range of 3/1/3 to 1/30/1. By setting the layer ratio in this range, the sheet can have appropriate flexibility and strength. More preferably, it is 1/2/1 to 1/20/1.

According to the present invention, the internal haze is 5% or less,
It has an external haze of 3% or less, a total light transmittance of 80% or more, a tensile modulus of 50 to 1000 MPa, a multilayer structure containing a polypropylene resin and a polyolefin resin, and at least one of its surface layers. Since an antimicrobial agent is added, a sheet having high transparency, appropriate flexibility and strength, and antimicrobial properties can be obtained. In addition, since it is a sheet mainly composed of polyolefin, chlorine-based gas,
High environmental adaptability without generating harmful substances such as dioxin. Further, there is no problem that the plasticizer bleeds out and the surface becomes sticky as in the case of the flexible PVC sheet.

As the polypropylene resin layer constituting the soft transparent antibacterial polyolefin sheet described above, various polypropylene layers such as homopolypropylene, block polypropylene, and random polypropylene can be used. Tic polypropylene and propylene-
It is preferable that the resin is made of a resin mainly composed of any one of an ethylene-1-butene terpolymer. Further, a layer composed of a resin obtained by blending two or more of these polypropylene resins can also be used.

On the other hand, as the polyolefin resin layer,
It is preferable to use a resin mainly composed of a copolymer of ethylene and α-olefin. As such a resin,
Ethylene and a small amount of α-olefin (C4, C6, C8
Linear low-density polyethylene (LLDPE), a metallocene-based LLDPE, and the like. Further, as the polyolefin resin layer, any one of ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-methyl acrylate copolymer (EMA), and ionomer is used. A layer composed mainly of a resin can also be used. As the ethylene-vinyl acetate copolymer, those having a vinyl acetate content of 10 to 25% by weight are preferred. In addition,
As the polyolefin-based resin layer, a layer made of a low-density polyethylene resin can be used, and a layer made of a resin obtained by blending two or more kinds of the polyolefin-based resins described above can also be used.

In the above, it is preferable that the surface roughness of at least one sheet surface is Ra = 0.2 μm or less. That is, if the surface of the sheet has irregularities, the ratio of light reflection increases due to the angle of incidence of light, causing so-called irregular reflection, and has a great effect on the quality of gloss. When the surface roughness is quantitatively expressed by the center line average roughness Ra, by setting the surface roughness to 0.2 μm or less, it is possible to prevent irregular reflection and a decrease in gloss.

The thickness of the soft transparent antibacterial polyolefin sheet is preferably 0.05 to 0.5 mm. If the thickness of the sheet is less than 0.05 mm, the sheet may be too thin and low molecular components may easily bleed out. On the other hand, when it exceeds 0.05 mm, transparency and flexibility may be deteriorated. Preferably 0.15-
It is 0.5 mm, more preferably 0.15 to 0.3 mm.

In addition, a lubricant, an antiblocking agent, a nucleating agent, an antistatic agent, a light stabilizer (HALS), an antioxidant,
It is also possible to add a petroleum resin, an antibacterial agent, an antifogging agent, a thermoplastic elastomer, etc. to adjust the properties. The concept of the sheet of the present invention includes a relatively thin film.

A bag-making product according to the present invention is obtained by bag-making the soft transparent antibacterial polyolefin sheet according to any one of claims 1 to 11. Various bag-making methods such as sewing, heat sealing, high-frequency sealing, and ultrasonic sealing can be adopted as a method of forming the sheet.However, in consideration of easiness of bag-making, heat sealing, high-frequency sealing, and It is preferable to employ any method of ultrasonic sealing.

According to the present invention, since the above-mentioned soft transparent antibacterial polyolefin-based sheet is made into a bag to make a bag product,
The transparency of the bag is high, and the contents can be easily checked from the outside. In addition, since it is composed of a sheet having a multilayer structure, it is possible to obtain a bag product having relatively high strength.
Furthermore, since an antibacterial agent is added, a bag-making product having antibacterial properties can be obtained. And since it is a bag-making product which has a polyolefin resin as a main component, a plasticizer does not bleed out like a flexible PVC sheet and does not stain contents.

The above-mentioned soft transparent antibacterial polyolefin-based sheet, and the bag-making product obtained by subjecting it to secondary processing such as heat sealing, include stationery (pen case, scissor case, ruler case, name plate, etc.), CD- It can be suitably used for ROM cases, music CD cases, portable bags, cosmetics cases and handbags, shampoo and rinse cases, handbags, toothbrush cases, refrigerator curtains and the like.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a soft and transparent antibacterial polyolefin-based sheet 1 (hereinafter, referred to as a sheet) according to an embodiment of the present invention.
PO-based sheet 1) is shown. The PO sheet 1 has a three-layer structure of a polypropylene resin layer 11A / polyolefin resin layer 11B / polypropylene resin layer 11C.

Here, the polyolefin-based resin layer 11B, which is the intermediate layer, is made of a linear low-density polyethylene resin. Further, the polypropylene-based resin layers 11A and 11C, which are both outer layers (surface layers), are made of a random polypropylene resin to which the antibacterial agent 10 is added. The antibacterial agent 10 is obtained by converting silver oxide (Ag ₂ O) into boric acid-silicate glass (SiO ₂ / B ₂ O ₃ / Al ₂ O ₃ / Na ₂ O / Z).
nO) is used.

The PO-based sheet 1 is a transparent sheet having an internal haze of 5% or less, an external haze of 3% or less, a total light transmittance of 80% or more, and a tensile modulus of 50 to 1000 MPa. In addition, the polypropylene-based resin layer 11
A and 11C have a surface roughness Ra of 0.2 μm or less. In addition, each layer 11A, 1
In the present embodiment, the layer ratio between 1B and 11C is 1/8/1, and the thickness is 0.2 mm.

Next, a manufacturing apparatus and a manufacturing method of the PO sheet 1 will be described with reference to FIG. The manufacturing apparatus includes a T-die 12 for co-extrusion of molten resin extruded from three extruders (not shown) as three kinds of three-layered molten resin, a first cooling roll 13 and a second cooling roll 14, Between the metal endless belt 15, the third cooling roll 16 in contact with the first cooling roll 13 via the PO-based sheet 1 and the metal endless belt 15, and the vicinity of the second cooling roll 14. And a fourth roll 17 provided.

The surface of the first cooling roll 13 is coated with an elastic material 18 such as fluororubber. This elastic material 18
Has a hardness (according to JIS K-6301 A type) of 60 degrees and a thickness of 10 mm. The hardness and the thickness can be appropriately set according to the thickness of the sheet, the raw material and the like, but are preferably 95 degrees or less in hardness and 3 mm or more in thickness.

The metal endless belt 15 is made of stainless steel or the like, and has a mirror surface having a surface roughness of 0.5 S or less. At least one of the first and second cooling rolls 13 and 14 has a rotating shaft 19 whose rotation driving means (not shown).
Is linked to

The third cooling roll 16 also has a surface roughness of 0.5
It has a mirror surface of S or less. And this cooling roll 1
6 is provided so as to abut against the first cooling roll 13 via the PO-based sheet 1 and the metal endless belt 15 and to embrace the PO-based sheet 1 pressed against the cooling roll 16 by the endless belt 15. I have. That is, the metal endless belt 15 and the PO-based sheet 1 in contact with the endless belt 15 meander so as to wind around a part of the outer peripheral surface of the third cooling roll 16.

The fourth roll 17 guides the PO sheet 1 so that the PO sheet 1 is pressed against the second cooling roll 14 via the endless belt 15. Each of the cooling rolls 13, 14, 16 is provided with a temperature adjusting means (not shown) of a water-cooling type or the like capable of adjusting the surface temperature. As shown by the dashed line in FIG. 2, a cooling roll 21 is further provided before the first cooling roll 13 in the endless belt 15, and an upstream portion of the endless belt 15 reaching the first cooling roll 13 is cooled in advance. You may do so. The cooling roll 21 also functions for adjusting the tension of the endless belt 15.

Next, a method for manufacturing the PO sheet 1 of this embodiment using the above-described manufacturing apparatus will be described. First, the surface temperature of the metal endless belt 15 and the third cooling roll 16 which are in direct contact with the PO-based sheet 1 are higher than the dew point and 50 ° C.
As will be kept below, each cooling roll 13, 14, 16
Temperature control. In addition, PO supplied to each extruder
As raw materials for the system sheet 1, a random polypropylene resin pellet to which an antibacterial agent is added and a linear low-density polyethylene resin pellet are prepared.

After each of these raw materials is put into an extruder and melted and kneaded, the molten PO-based sheet 1 coextruded into three layers from a T-die 12 is first cooled by a first cooling roll 1.
The third cooling roll 13 is introduced between the first and third cooling rolls 13 and 16 so as to contact the endless belt 15 and the third cooling roll 16 at the same time. Here, the first and third cooling rolls 13 and 16 are used for the PO-based sheet 1.
And cooled to 50 ° C. or less. At this time, the elastic material 18
Is elastically deformed by being compressed by the pressing force between the first and third cooling rolls 13 and 16. Angle θ1 from the center of both rolls 13 and 16 in which this elastic material 18 is elastically deformed
In the part, the PO-based sheet 1 includes both rolls 13 and 16.
Are pressed in a plane. The surface pressure at this time is 0.1 to
20.0 MPa.

Subsequently, the PO-based sheet 1 is pressed against the third cooling roll 16 with a mirror endless belt 15 to
Cool below 0 ° C. The PO-based sheet 1 pressed toward the cooling roll 16 by the mirror endless belt 15 is embraced by the cooling roll 16 at an angle θ2 from the center of the cooling roll 16, and the endless belt 15 and the third The sheet is pressed in a planar manner by a cooling roll 16. The surface pressure at this time is 0.01 to 0.5 MPa.

Next, the PO sheet 1 is moved toward the second cooling roll 14 together with the rotation of the endless belt 15 in a state where the PO sheet 1 is overlapped with the endless belt 15, and the PO sheet 1 is moved to the endless belt 15. Through the second
The PO sheet 1 of the present embodiment is manufactured by being pressed against the cooling roll 14 and cooled to 50 ° C. or lower. Where PO
When the system sheet 1 is pressed toward the cooling roll 14 by the guide of the fourth roll 17, the PO sheet 1 is angled θ3 from the center of the cooling roll 14 via the endless belt 15.
The parts are pressed in a planar manner. The surface pressure at this time is
It is 0.01 to 0.5 MPa. The PO-based sheet 1 cooled by the third cooling roll 16 is
You may make it pick up directly, without moving to the side.

The obtained PO-based sheet 1 and the bag-making product subjected to secondary processing such as heat sealing are used for stationery (pen case, writing instrument case with fastener, file case,
Card case, file case with zipper, etc.), CD-
It can be suitably used for ROM cases, music CD cases, portable bags (fashion bags, travel bags, etc.), cosmetics cases and handbags, shampoo and rinse cases, handbags, toothbrush cases, refrigerator curtains and the like.

According to the above-described embodiment, the following effects can be obtained. (1) The first and third rolls 1 in which the elastic material 18 is elastically deformed with respect to the PO-based sheet 1 extruded from the T die 12.
In the angle θ1 portion of 3, 16 the two rolls 13, 16
The sheet 1 is pressed against the sheet 1 and cooled, and then the metal endless belt 15 and the third
After performing the surface pressing and cooling of the PO-based sheet 1 by the cooling roll 16, the P by the endless belt 15 and the second cooling roll 14 is formed at the angle θ3 of the second cooling roll 16.
Since the O-type sheet 1 is subjected to planar pressing and cooling, the PO-type sheet 1 having appropriate transparency can be manufactured at a high speed.

(2) PO sheet 1 has an internal haze of 5%
Hereinafter, the external haze is 3% or less, the total light transmittance is 80% or more, the tensile modulus is 50 to 1000 MPa, and
Since it has a three-layer structure of the polypropylene-based resin layer 11A / polyolefin-based resin layer 11B / polypropylene-based resin layer 11C, the PO-based sheet 1 having high transparency and appropriate flexibility and strength can be obtained. . (3) Since the surface roughness Ra of the polypropylene-based resin layers 11A and 11C is set to 0.2 μm or less, irregular reflection on the surface of the PO-based sheet 1 and a decrease in gloss can be prevented. (4) Since the antimicrobial agent 10 is added to the polypropylene resin layers 11A and 11C, which are both outer layers, the PO sheet 1
Antibacterial properties are exhibited on both sides of the.

(5) The antibacterial agent 10 is obtained by converting silver oxide (Ag ₂ O) to boric acid-silicate glass (SiO ₂ / B ₂ O ₃ / Al ₂ O ₃ /
(Na ₂ O / ZnO), the elution of silver ions can be prevented, and antibacterial properties can be maintained for a long time. (6) PO sheet 1 mainly composed of polyolefin resin
Therefore, even in the case of incineration disposal, it has high environmental adaptability without generating harmful substances such as chlorine-based gas and dioxin. Further, unlike the flexible PVC sheet, the plasticizer does not bleed out and causes no problem such as stickiness.

It should be noted that the present invention is not limited to the above embodiment, and modifications and improvements as long as the object of the present invention can be achieved are included in the present invention. For example, P
Mirror endless belt 1
Although the apparatus having No. 5 was used, the invention is not limited to this, and any sheet manufacturing apparatus can be adopted as long as the physical properties of the PO-based sheet of the present invention can be obtained. In addition, the PO-based sheet 1 having a three-layer structure is obtained by the co-extrusion method. However, the present invention is not limited to this. For example, three T dies corresponding to the extruders for each layer are used, and the melt extruded from these is used. A method of laminating a resin on a mirror endless belt can also be adopted.

In the above embodiment, the PO-based sheet 1 has a three-layer structure, but is not limited to this. That is,
Any number of layers may be used as long as it has a multilayer structure including a polyolefin-based resin layer and a polypropylene-based resin layer. Further, the antibacterial agent is added to both outer layers of the polypropylene-based resin layers 11A and 11C. However, the present invention is not limited to this. The antibacterial agent may be added to only one of the outer layers. Further, as an antibacterial component of the antibacterial agent 10, silver oxide (A
g ₂ O), but is not limited to this. That is, other inorganic antibacterial agents, silver antibacterial agents, and organic antibacterial agents having antibacterial properties can also be used. Furthermore, boric acid as a carrying body - silicate based glass (SiO ₂ / B ₂ O ₃
/ Al ₂ O ₃ / Na ₂ O / ZnO), but is not limited thereto, and various types of glass, silica, alumina, zeolite and the like can be used.

In the above embodiment, the thickness of the PO-based sheet 1 is 0.2 mm, but is not limited to this value.
Any thickness can be set as long as transparency and flexibility are not impaired. The layer ratio of each of the layers 11A, 11B, and 11C constituting the PO-based sheet 1 is 1/8/1, but is not limited thereto, and can be appropriately set according to the purpose of use. .

In the above embodiment, random polypropylene is used as the polypropylene resin. However, the present invention is not limited to this. For example, syndiotactic polypropylene, homopolypropylene, propylene-ethylene-propylene terpolymer, or the like may be used. it can. Although the linear low-density polyethylene is used as the polyolefin-based resin, the invention is not limited to this, and LDPE, metallocene-based LLDPE, EVA, EMMA, EMA, ionomer, and the like can also be used. In addition, the specific structure, shape, and the like at the time of carrying out the present invention may be other structures and the like as long as the object of the present invention can be achieved.

[0043]

The present invention will now be described more specifically with reference to examples and comparative examples. [Examples 1 to 11] Using the manufacturing apparatus of the above embodiment,
Soft transparent antibacterial polyolefin-based sheet 1 having the layer structure, thickness, and antibacterial agent addition amount shown in Table 1 below was produced. In addition,
In Example 11, five extruders corresponding to each layer were used.

Comparative Example 1 Using the manufacturing apparatus of the above-described embodiment, sheets having the layer structure, thickness, and antimicrobial agent addition amount shown in Table 1 below were manufactured.

Comparative Example 2 The layer structure, thickness,
A sheet having an antimicrobial agent added amount was manufactured by a touch roll method.

Comparative Example 3 A sheet having the layer structure and thickness shown in Table 1 was produced using the above-described production apparatus without adding an antibacterial agent.

[0047]

[Table 1]

In Table 1, HPP is homopolypropylene (F-704NP, manufactured by Idemitsu Petrochemical Co., Ltd.),
RPP is random polypropylene (F-744NP, manufactured by Idemitsu Petrochemical Co., Ltd.), LL1 is linear low-density polyethylene (Affinity PL1880, manufactured by Dow Chemical Co., Ltd.), and LL2 is linear low-density polyethylene (affinity PL1850, Dow Chemical Co., Ltd.), S
PP is syndiotactic polypropylene (Tiaro SP
H-0452E, manufactured by Mitsui Chemicals, Inc.), EVA is an ethylene-vinyl acetate copolymer (Evaflex EV36)
0, manufactured by Mitsui Dupont Polychemical Co., Ltd.), and ternary PP is a propylene-ethylene-propylene terpolymer (HF
3193A, manufactured by Chisso Corporation).

The amorphous PP is 1-butene (35w).
t%) and a random copolymer of propylene (65 wt%) and an amorphous polyolefin (density 0.8%).
6g / cm ³ , melt viscosity at 190 ° C 10,000c
ps) 50 wt% and crystalline polypropylene (MI: 1
g / 10 min, density 0.90 g / cm ³ ) 50 wt%.

With respect to the sheets obtained in each of the above Examples and Comparative Examples, the tensile modulus, internal haze, external haze,
The total light transmission, gloss, surface roughness, antibacterial property, and bleeding property were measured and evaluated, and the results are shown in Table 2.

[0051]

[Table 2]

Here, the measurement and evaluation of each item were performed as follows. (1) Tensile modulus Measured by a method according to JIS K-7113. (2) Internal haze, external haze Measured according to the following method in accordance with JIS K-7105. Using a haze measuring machine (NDH-300A, manufactured by Nippon Denshoku Industries Co., Ltd.), the film was irradiated with light, and the total light transmittance (Tt) representing the total amount of light transmitted through the film, and the film was diffused and transmitted by the film. The internal haze and the external haze are determined from the ratio with the diffuse light transmittance (Td) according to the following equation.
Here, the total light transmittance (Tt) is defined as the parallel light transmittance (Tp) and the diffuse light transmittance (Tp) transmitted coaxially with the incident light.
d). Haze (%) = Td / Tt × 100 The internal haze was measured by applying silicone oil to both sides of the film, sandwiching both sides of the film with a glass plate, and eliminating the influence on the outside of the film. .

(3) Total light transmittance According to the method according to JIS K-7105, the above (2)
The total haze and the external haze were measured using the same apparatus. (4) Gloss The colored sheet is irradiated with light at an incident angle of 60 ° using an automatic colorimeter (AUD-CH-2 type-45, 60, manufactured by Suga Test Instruments Co., Ltd.). The reflected light flux ψs when the reflected light was received in ° was measured, and was determined as follows by the ratio to the reflected light flux ψos from the glass surface having a refractive index of 1.567. Gloss (Gs) = (ψs / ψos) × 100

(5) Surface roughness Measured by a method according to JIS B-0610-1982. Specifically, using a three-dimensional electron beam roughness analyzer (ERA-4000, manufactured by Elionix Inc.) as a measuring device, the surface is observed at a magnification of 1500 times, and fine irregularities on the sample surface are measured with an electron probe. It measured and calculated center plane average roughness SRa. In addition, the inside refers to the surface that comes into contact with the endless belt 15 of the manufacturing apparatus in FIG. 2, and the outside refers to the surface on the opposite side.

(6) Antibacterial property According to the film adhesion method (anti-technical association 1998 revised edition),
The viable count of Staphylococcus aureus at 35 ° C.
The comparison was made after a lapse of time, and evaluated according to the following criteria. ：: Viable cell count decreased by more than 100 times from initial stage ×: Viable cell count increased by more than 100 times from initial stage

(7) Bleedability The sheet was placed in a constant temperature bath at 80 ° C., taken out one month later, and the sheet was visually observed for cloudiness and dirt due to bleeding.
Evaluation was made according to the following criteria. ：: Bleed, no stain △: Slightly poor appearance ×: Extremely dirty

As shown in Table 2, the soft transparent antibacterial polyolefin sheets obtained in Examples 1 to 11 had an internal haze of 5% or less, an external haze of 3% or less, and a total light transmittance of 80% or more. It has a characteristic of a tensile modulus of 50 to 1000 MPa, and is excellent in transparency and glossiness, and has moderate flexibility. In addition, in the polypropylene resin and the polyolefin resin used in each of the examples, it can be seen that the respective characteristic values of the colored sheet are sufficiently satisfactory. Further, since the antibacterial agent is added to the polypropylene-based resin layers 11A and 11C, it can be seen that the antibacterial agent has a sufficient antibacterial property.

On the other hand, in Comparative Example 1, the intermediate layer was made of amorphous PP.
Therefore, it is understood that the bleeding property is inferior. Comparative Example 2
Since the sheet is manufactured by the ordinary touch roll method, it is understood that the optical characteristics are inferior. In Comparative Example 3, since no antibacterial agent was added, it was found that there was no antibacterial property.

Further, after the sheets obtained in each of the above Examples and Comparative Examples were sealed to produce a bag-made product, the bleeding property at 40 ° C. was evaluated. Table 3 shows the bag making method and the evaluation results.

[0060]

[Table 3]

Here, the bleeding property is as follows. A bag-made product in which an empty bottle of cosmetics is put in a bag is placed in a dryer at 40 ° C., left under high humidity, and the stickiness of the bag, the degree of dirt, etc. are observed. Then, the bag-making product was evaluated according to the following criteria. ：: No deterioration × 1: The surface is extremely sticky and the product is poor. × 2: The transparency is low and the product is poor. × 3: The part touched by hand is dirty and the product is poor.

As shown in Table 3, the bag-formed articles obtained by bagging the soft transparent antibacterial polyolefin sheets obtained in Examples 1 to 11 cause bleed-out even at 40 ° C. and high humidity. It can be seen that the merchantability is high without any. Further, it can be seen that good bag-making products were obtained by any of the heat sealing, ultrasonic sealing, and high frequency sealing.

On the other hand, the bag-made product obtained from the sheet of Comparative Example 1 was found to be very sticky and dirtied by the bleed material, as in the case of the sheet. The bag product obtained from the sheet of Comparative Example 2 has no problem in bleeding property,
It turns out that transparency is inferior and commercial value is low. The bag-made product obtained from the sheet of Comparative Example 3 has no problem with the bleeding property, but since no antibacterial agent is added, the part touched by hand is easily stained, and it is understood that the commercial value is low.

[0064]

According to the present invention, the soft transparent antibacterial polyolefin sheet has an internal haze of 5% or less, an external haze of 3% or less, a total light transmittance of 80% or more, and a tensile modulus of 50 to 1000 MPa. Yes, and has a multilayer structure, and since an antimicrobial agent is added to at least one of its surface layers, it is possible to form a sheet having high transparency, moderate flexibility and strength, and antibacterial properties. it can. Further, since the sheet is mainly composed of polyolefin, it does not generate harmful substances such as chlorine-based gas and dioxin even in the case of incineration disposal, and has high environmental adaptability.
Further, there is no problem that the plasticizer bleeds out and the surface becomes sticky as in the case of the flexible PVC sheet.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a soft transparent antibacterial polyolefin-based sheet according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a sheet manufacturing apparatus in the embodiment of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Soft antibacterial transparent polyolefin sheet 10 Antibacterial agent 11A, 11C Polypropylene resin layer 11B Polyolefin resin layer 15 Metal endless belt 16 Third cooling roll 18 Elastic material

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A01N 59/16 A01N 59/16 A B32B 27/18 B32B 27/18 F B65D 65/40 B65D 65/40 D F-term (reference) 3E086 AB01 AD01 BA04 BA15 BB22 BB51 BB85 BB90 DA01 4F100 AA40A AA40B AA40C AA40H AG00A AG00B AG00C AG00H AK03A AK03B AK04A AK04B AK04C AK04J AK07A AK07B AK07C AK07J AK09A AK09B AK09C AK09J AK62A AK62B AK62C AK68A AK68B AK68C AK71A AK71B AK71C AK80A AK80C AL01A AL01B AL01C AL05A AL05B BA02 BA03 BA07 BA10A BA10C BA11 BA16 CA12A CA12B CA12C DD07 GB16 JC00A JC00B JC00C JK01 JK07 JK13 JL16 JN01 JN08A JN08B JN08C YY00 YY00A YY00B YY00B YY00B YY00B YY00C

Claims (13)

[Claims] An internal haze of 5% or less and an external haze of 3%
Hereinafter, the total light transmission is 80% or more, and the tensile modulus is 50 to 50%.
A soft transparent antibacterial polyolefin sheet having a multilayer structure including a polypropylene-based resin layer and a polyolefin-based resin layer and having an antibacterial agent added to at least one of its surface layers. 2. The soft transparent antibacterial polyolefin sheet according to claim 1, wherein the surface layer comprises a polypropylene resin layer. 3. The soft transparent antibacterial polyolefin sheet according to claim 1, wherein the multilayer structure is a three- to nine-layer structure. 4. The soft transparent antibacterial polyolefin sheet according to claim 1, wherein the multilayer structure has a three-layer structure of a polypropylene resin layer / polyolefin resin layer / polypropylene resin layer. A soft transparent antibacterial polyolefin-based sheet characterized by the following. 5. The soft transparent antibacterial polyolefin sheet according to claim 1, wherein the antibacterial agent is a silver antibacterial agent. 6. The soft transparent antibacterial polyolefin sheet according to claim 5, wherein the silver antibacterial agent is a silver compound carried on glass. 7. The soft transparent antibacterial polyolefin sheet according to claim 1, wherein the polypropylene resin layer is made of random polypropylene, syndiotactic polypropylene, and propylene-ethylene-1-butene3. A soft transparent antibacterial polyolefin-based sheet comprising a resin mainly composed of any one of copolymers. 8. The soft transparent antibacterial polyolefin-based sheet according to claim 1, wherein the polyolefin-based resin layer is made of a resin mainly composed of a copolymer of ethylene and α-olefin. A soft transparent antibacterial polyolefin sheet characterized by the following. 9. The soft transparent antibacterial polyolefin sheet according to any one of claims 1 to 8, wherein the polyolefin resin layer comprises an ethylene-vinyl acetate copolymer, an ethylene-methyl methacrylate copolymer, A soft transparent antibacterial polyolefin-based sheet comprising a resin mainly composed of any one of an ethylene-methyl acrylate copolymer and an ionomer. 10. The soft transparent antibacterial polyolefin sheet according to claim 1, wherein at least one of the sheets has a surface roughness Ra = 0.
A soft transparent antibacterial polyolefin sheet having a thickness of 2 μm or less. 11. The soft transparent antibacterial polyolefin sheet according to claim 1, wherein the sheet has a thickness of 0.15 to 0.5 mm. System sheet. 12. A bag-formed article obtained by bag-forming the soft transparent antibacterial polyolefin sheet according to any one of claims 1 to 11. 13. The product according to claim 12, wherein said soft transparent antibacterial polyolefin sheet is made by any one of heat sealing, high frequency sealing and ultrasonic sealing. Bag products.