JP3524126B2 - Freshness retention film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film for maintaining freshness.
You. For more details, broccoli, plum, asparaga
Sugar, cherry, mushrooms and other fruits and vegetables with a large respiration rate in a packaging bag
Wrapped in the atmosphere_Two, CO_TwoOptimize concentration and freshness
The present invention relates to a film for hermetic packaging that maintains the degree. [0002] 2. Description of the Related Art In recent years, consumption of fruits and vegetables for freshness
Needs are high and how to maintain their freshness after harvest
Ruka is very important together with cultivation techniques for fruits and vegetables.
You. Focusing on maintaining freshness to respond to these requests
Development of packaging films is under way, for example,
Method for removing ethylene causing aging
309137, JP-A-63-110186), far infrared rays
For activating cells by generating DNA
10973), humidity control in the bag (JP-A-58-1936)
78), a method based on an anti-fogging effect (JP-A-62-1104)
9), a method based on an antibacterial effect (JP-A-61-14823)
6) Various measures have been proposed. However many
An effective method of maintaining freshness for various fruits and vegetables and flowers
Has not been found. In other words, each individual special case
The sauce has a freshness preserving effect, but it is made of different fruits and vegetables.
It is very difficult to achieve the same effect. [0003] Fruits and vegetables with a particularly high respiration (broccoli,
Asparagus, plum, cherry, mushroom, etc.)
O package_TwoConcentration too low for suffocation
Fermentation and odors caused by anaerobic breathing
It is. On the other hand, if it is folded, it will not be possible to control the breathing volume,
The freshness drops sharply. So these fruits and vegetables with high respiration
It does not suffocate even if the package is sealed and has a moderate O_TwoConcentration and
Film that exhibits the effect of maintaining freshness
-Methyl-1-pentene polymer-based film
(Japanese Unexamined Patent Publication No. 4-20237),
When a methyl-1-pentene polymer is used as a main component, a low temperature (0%
The film hardens and cracks under the environment)
Poor. [0004] Poly 4-methyl-1-pe
Laminated gusset bag of stainless steel and nonwoven fabric (Japanese Patent Laid-Open No. 5-1530)
5) has been reported, but there is a drawback that the contents cannot be seen.
You. Make a small hole in the film and set a moderate O inside the bag._Twoconcentration
(Japanese Unexamined Patent Publication No. Hei 4-5344)
5, 54-40793, 63-119647)
How to make a hole to increase the gas permeability of the whole film
Now, use a film with high gas permeability without making holes
Same as compared to_TwoCO at concentration_TwoHigh concentration
The possibility of failure is high, and
The gas permeability of the film even if the respiration rate of fruits and vegetables changes
Does not change, the range of change in the gas composition in the bag increases.
As a result, the effect of maintaining freshness is not stable. [0005] [Problems to be Solved by the Invention]
Sealed and packaged, O_Two, CO_TwoDark
Freshness preserving film with optimal density
It has not been. [0006] SUMMARY OF THE INVENTION The gist of the present invention is as follows.
-Ethyl acrylate copolymer (hereinafter referred to as EEA)
May be present),4-methyl-1-pentene polymer (hereinafter referred to as 4
Sometimes called M1P) AndUnsaturated carvoneAcid changesex
PolyolefinspecificCharacterized by consisting of a mixture
Exist in freshness retaining film. EEA used in the present invention
Ethyl acrylate(Hereinafter sometimes referred to as EA)Including
Quantity is 15Weight% or more40% by weightLess thanUse.1
If it is less than 5% by weight, the gas permeability becomes too small.
If it is more than 0% by weight, the film becomes sticky, strong, and molded.
Not suitable for sex. 4M1P is 10 to 10% of the total weight of the mixture.
40% by weightUse. If less than 10% by weight, gas permeability
Is too low, and if it is more than 40% by weight, mixing with EEA
The film surface is rough and rough. The feature of the present invention is that EEA and 4M1P are shaken.
In terms of handling. EEA is a gas with increasing EA content
Transmittance rises sharply but the film is sticky
Blocking is severe and practicality is lost. 4M1P also non
It is a resin that always has high gas permeability, but it is hard
The film is easily broken at low temperatures. EEA and 4M1P
By rendering, even when using EEA with high EA content,
Eliminates blocking of lum and breaks film at low temperatures
And a practical film that transmits gas very well
It is done. [0008] In order to increase the compatibility between EEA and 4M1P,
Add saturated carboxylic acid modified polyolefin.4M1P
WhenUnsaturated carboxylic acid-modified polyolefinWithWeight ratio(4
M1P / unsaturated carboxylic acid-modified polyolefin)4 /
1 to 1/2Use. If it is larger than 4/1, the compatibilizing effect is
Insufficient, film surface is rough, smaller than 1/2
And the EEA content is too low and the gas permeability is low
I will. What is an unsaturated carboxylic acid-modified polyolefin?
Acrylic acid, methacrylic acid, maleic acid, fumaal
Acids, unsaturated carboxylic acids such as itaconic acid or derivatives thereof
Graft-modified polyolefin resin, especially anhydrous
Polyolefin graft modified with maleic acid is preferred
No. The amount of unsaturated carboxylic acid graft
0.01 to 5 parts by weight, preferably 100 parts by weight of fins
Or 0.02 to 0.5 parts by weight. Unsaturated carvone
Acid-modified polyolefins are not suitable for melt
Is 0.5 to 20 g / 10 min, preferably 1.0 to
It is preferable that the amount is about 10 g / 10 minutes. The film of the present invention
Insufficient strength or sticky film
Poor openability or insufficient heat sealability
In this case, a multilayer with another resin may be used. However, the gas permeability is reduced as much as possible.
There is no other laminated film for the film of the present invention
Is preferably 10/0 to 7/3. usable
Examples of the laminating resin include polyethylene and polypropylene.
Len, EEA having an EA content of 10% by weight or less, vinyl acetate
Ethylene-vinyl acetate having a content (VA) of 10% by weight or less
Copolymer (EVA), polystyrene, polybutadiene, etc.
Is mentioned. The total thickness of the film is the
Depends on absorption, weight, temperature, etc.
The range is preferably from 100 to 100 μm. Known methods for forming into a film
Method is available. Single layer inflation method, T die
In addition to the method, when forming a multilayer, the inflation
Multi-layer method by lamination method, T-die method or lamination
Can also be In addition, plasticizers usually added to resin, heat stable
Agent, antioxidant, filler, lubricant, anti-blocking
Agents, UV absorbers, coloring agents, modifiers, etc.
You can use it. Also important for keeping freshness
It is possible to add antibacterial agent, antifogging agent, ethylene removing agent, etc.
is there. [0012] The freshness retaining film of the present invention originally has a respiratory volume.
Exposure to abundant fruits and vegetables, distribution and storage at normal and high temperatures
Suitable for keeping fruits and vegetables fresh, such as heat sealing and rubber band packaging
O in the bag by sealed packaging_Two, CO_TwoOptimize concentration
You. The sealed packaging of such high respiratory fruits and vegetables does not cause asphyxiation or carbonation.
Although gas barrier is a problem, this film has an oxygen permeability Po
_TwoVery high, O in the bag_TwoSince the concentration is not too low,
Prevents breathing and permeates carbon dioxide against oxygen permeability
Rate (hereinafter referred to as PR) is high, so CO_TwoConcentration
Lowering, carbon dioxide damage is less likely to occur. [0013] Next, the present invention will be described with reference to examples.
The invention is not limited to these examples. What
The Pco in the examples_Two, Po_TwoMeasurement of pressurized gas
Transmittance measurement method (Gasperm-100 manufactured by JASCO Corporation)
(Type) at 23 ° C. Example 1 EEA (Mitsui DuPont Polychemical Co., Ltd., trade name: EV
AFLEX-EEAA714, EA = 25% by weight) 50
Wt%, 4M1P (Mitsui Petrochemical Co., Ltd., trade name: T
PXMX001) 20% by weight, unsaturated carboxylic acid-modified poly
Reolefin (Mitsubishi Kasei Co., Ltd., trade name: AP730T)
30% by weight, and the thickness is 30μ by inflation method.
m was formed. The molding temperature is 260 ° C
Was. O of this film_Two, CO_TwoTransmittance Po_Two, Pc
o_TwoWhen you measure Po_Two= 42000 [CC / m^Two・ Day ・ at
m] Pco_Two= 218000 [CC / m^Two・ Day ・ at
m] Pco_Two/ Po_Two(PR) = 5.20 A plant test is performed using the obtained film.
Was. <Broccoli freshness test> 12 broccoli
(3 kg) packed in a 70 cm x 65 cm bag,
saved. Table 1 shows the test results after 3 days. <Shiitake mushroom freshness test> 6 shiitake mushrooms (100g)
Was packaged in a 20 cm × 30 cm bag and stored at 25 ° C.
Table 2 shows the test results after two days. Embodiment 2 EEA 25% by weight, 4M1P 30% by weight, unsaturated carb
Except that the acid-modified polyolefin was 45% by weight,
A 30 μm thick film was formed in the same manner as in Example 1.
Was. Po of this film_Two, Pco_TwoWhen you measure Po_Two= 39800 [CC / m^Two・ Day ・ at
m] Pco_Two= 195000 [CC / m^Two・ Day ・ at
m] PR = 4.90. Displays the results of the freshness retention test
1 and Table 2. Embodiment 3 EEA 50% by weight, 4M1P 40% by weight, unsaturated carb
Except that the acid-modified polyolefin was 10% by weight.
A 30 μm thick film was formed in the same manner as in Example 1.
Po of this film_Two, Pco_TwoWhen you measure Po_Two= 46000 [CC / m^Two・ Day ・ at
m] Pco_Two= 244000 [CC / m^Two・ Day ・ at
m] PR = 5.30. Displays the results of the freshness retention test
1 and Table 2. Embodiment 4 Example 1 The composition film of Example 1 and low density polyethylene (Mitsubishi Chemical
Seiko F131) with a thickness ratio of 9/1.
Into a film by inflation method
I got it. Po of this film_Two, Pco_TwoMeasure
When Po_Two= 32000 [CC / m^Two・ Day ・ at
m] Pco_Two= 148000 [CC / m^Two・ Day ・ at
m] PR = 4.63. Displays the results of the freshness retention test
1 and Table 2. Comparative Example 1 Other than 70% by weight of EEA and 30% by weight of 4M1P
A 30 μm thick film was formed in the same manner as in Example 1.
Was. The dispersion of 4M1P is poor and the film has irregularities.
Pinholes were formed during molding and stable molding could not be performed. Fresh
The results of the temperature retention test are shown in Tables 1 and 2. Comparative Example 2 EEA 20% by weight, 4M1P20
Weight%, unsaturated carboxylic acid modified polyolefin 60 weight
% And a thickness of 30 μm in the same manner as in Example 1.
A film was formed. Po of this film_Two, Pco_Two
When you measure Po_Two= 12000 [CC / m^Two・ Day ・ at
m] Pco_Two= 504000 [CC / m^Two・ Day ・ at
m] PR = 4.20. Displays the results of the freshness retention test
1 and Table 2. Comparative Example 3 EEA has 9% by weight of EA (Mitsui DuPont Polychem
EVA FLEX-EEA A701 manufactured by Cal Co., Ltd.) was used.
Except for this, a film having a thickness of 30 μm was prepared in the same manner as in Example 1.
Was molded. Po of this film_Two, Pco_TwoMeasure
When Po_Two= 21000 [CC / m^Two・ Day ・ at
m] Pco_Two= 100000 [CC / m^Two・ Day ・ at
m] PR = 4.76. Displays the results of the freshness retention test
1 and Table 2. Comparative Example 4 EEA 90% by weight, 4M1P 5% by weight, unsaturated carboxyl
Example except that the acid-modified polyolefin was 5% by weight.
A film having a thickness of 30 μm was formed in the same manner as in Example 1. Fi
Lum's blocking is so severe that it will not be a practical film
Was. Tables 1 and 2 show the results of the freshness retention test. Comparative Example 5 EEA 30% by weight, 4M1P 50% by weight, unsaturated carb
Except that the acid-modified polyolefin was 20% by weight.
A 30 μm thick film was formed in the same manner as in Example 1.
The film surface was rough and did not become a practical film. Fresh
The results of the temperature retention test are shown in Tables 1 and 2. Comparative Example 6 Low density polyethylene (F131 manufactured by Mitsubishi Kasei)
Into a single layer film with a thickness of 30 μm
Was. (Molding temperature 160 ° C) Po of this film_Two, Pc
o_TwoWhen you measure Po_Two= 8100 [CC / m^Two・ Day ・ atm] Pco_Two= 30000 [CC / m^Two・ Day ・ atm] PR = 3.70. Displays the results of the freshness retention test
1 and Table 2. [0024] [Table 1] [0025] [Table 2][0026] According to the present invention, fruits and vegetables having a high respiration rate can be densely distributed.
Demonstrates CA effect without suffocation even in sealed packaging and maintains freshness
A practical film can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08L 23/08 C08L 23/08 // C08L 23:08 23:08 23:20 23:20 23:26 23:26 (56) References JP-A-4-202437 (JP, A) JP-A-2-282080 (JP, A) JP-A-63-254148 (JP, A) JP-A-58-127772 (JP, A) JP-A-51 -143087 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 5/18 C08L 23/00-23/36 A23B 7/00, 7/148 B65D 65/40, 81 / 26

Claims (1)

(57) [Claim 1] An ethylene-ethyl acrylate copolymer,
Ri Do from 4-methyl-1-pentene polymer and an unsaturated mixture of the carboxylic acid-modified polyolefin, said mixture
10 to 40% by weight of 4-methyl-1-pentene polymer
And a 4-methyl-1-pentene polymer and an unsaturated
The weight ratio with the boronic acid-modified polyolefin is 4/1 to 1/2.
Is the ethylene-ethyl acrylate copolymer
When the acrylate content is 15% by weight or more and 40% by weight or less
Freshness retaining film which is characterized in Rukoto Oh.