JP2000026624A5 - - Google Patents

Description

0007
[Means for solving problems]
That is, in the present invention, 1 to 20 parts by weight of the liquid additive (B) is added to 100 parts by weight of the resin (A) mainly composed of a glycolic acid (PGA) -based aliphatic polyester resin having a crystal melting point of 120 to 250 ° C. A stretched film comprising the resin composition (C) containing the film, which has a crystallinity of 15 to 70%, a tensile elasticity of 20 to 150 kg / mm ² , and a heat shrinkage rate of X% at 100 ° C. and heat shrinkage. stress Yg / mm ² is within the range of relation of the following formulas (1) to (3), an adhesion resistant wrap film heat resistance, characterized in der Rukoto than 120 ° C..
Equation (1) Y ≦ (1400-20X) / 3
Equation (2) 2 ≤ X ≤ 45
Equation (3) 5 ≤ Y ≤ 350

Further, the range of saturated crystallinity of the aliphatic polyester as a raw material is usually about 15 to 80%, preferably 20 to 70%. The range of crystallinity of the film is usually about 15 to 70%, preferably 20 to 60%, the lower limit of these is limited by the heat resistance of the film, and the upper limit is insufficient molding processability of the raw material and flexibility. It is limited by lack of sexuality (in addition to lack of flexibility by itself, it becomes difficult to uniformly contain the plasticizer, and it becomes difficult to impart effective adhesion), transparency of the film, and the like. However, due to the characteristics of the raw material, after processing into a film due to the influence of processing conditions (quenching, etc.) and additives (crystal control), the crystallinity is further lower than the above, but this is used by heating (for example, cooking). ) during and immediately crystallize faster crystallization rate, as a result effectively heat resistance out (film is locally too, melt, if perforation does not), the limit value a lower limit prior to use film crystallinity this Not limited. In this case, among the above-mentioned aliphatic polyesters, waste treatment of a type of resin that has a biodegradable function but has a high degree of crystallization (when composted together with garbage during disposal) is difficult to biodegrade. May be preferred to facilitate.

These additives include aliphatic alcohols, alicyclic alcohols, polyhydric alcohols thereof, and at least one alcohol selected from these condensed polymers , the alcohol components and aliphatic fatty acids, aliphatic or aromatic polycarbons. esters of at least one fatty acid selected from the valence carboxylic acids, esters of aliphatic hydroxycarboxylic acids with alcohols and / or fatty acids, as well as modified products of these esters, polyoxyethylene alkyl ethers and or esters thereof, the resin ( More preferably, a plasticizer selected from the group consisting of the oligomer of A), mineral oil, liquid paraffin, and a low polymer composed of a saturated hydrocarbon compound can be used. Although not limited to the examples, these include polyglycerins such as glycerin, diglycerin, ..., Which are used as raw materials for alcohol components, and aliphatic fatty acids such as lauric acid, palmitic acid, stearic acid, and olein as acid components. At least one ester selected from mono, di, tri, ..., polyester and the like with acid, linoleic acid, ..., etc., or ester of sorbitan and the above fatty acid, or ethylene glycol, propylene glycol, tetramethylene glycol. , And an ester of these fatty acids and the above fatty acid, or an ester of citric acid, malic acid, tartaric acid, etc. as an aliphatic hydroxycarboxylic acid and a lower alcohol having 10 or less carbon atoms, or a polyhydric carboxylic acid. Examples include esters of malonic acid, succinic acid, glutaric acid, adipic acid, etc. and aliphatic alcohols, or modified products of these esters such as epoxidized soybean oil, epoxidized linseed oil, and the like.

The range of heat resistance in this film is 120 ° C. or higher, preferably 130 ° C. or higher, and more preferably 140 ° C. or higher. The reason for the lower limit is that in a microwave oven or the like, the contents are scattered due to film shrinkage due to packaging tearing during heating, the contents are too dry, and local heating is caused by lack of water. Since it is linked with the characteristics (for example, deterioration of workability, excessive tensile elastic modulus, etc.), it is preferably about 270 ° C. The reason for the above range is that it is good for the time being if the film is not damaged by steam at about 100 ° C at the initial stage of heating in a microwave oven, etc. If the content contains a mixture of oil components and salts, the temperature may be particularly high, and if the heat resistance is poor, holes will open and the film components will melt, which is not good for hygiene. This is because if the film is packaged and heated without a container, the film may be welded, and the package may not be taken out as it is unless the package is brought into close contact with a vacuum state and the contents are separated.

The resin composition (C) used here is as follows.
C-1; Polyglycolic acid (A-8: crystal melting point 225 ° C., crystallinity 60%) 80% by weight, L-lactic acid and glycolic acid 5 mol% copolymerized resin (crystal melting point 162 ° C., crystallinity degree) A composition C-2; A-7 in which 4 parts by weight of B-2, 2 parts by weight of B-5, and 1 part by weight of B-1 are mixed with 100 parts by weight of 20% by weight of 38%). 80% by weight plus 20% by weight of ethylene-vinyl alcohol copolymer resin (39 mol% ethylene copolymer) 100 parts by weight, 3 parts by weight of B-1 and 3 parts by weight of B-5 mixed Composition C-3; A-7 was added to 85% by weight and 15% by weight of a hydrogenated copolymer (crystallinity melting point 220 ° C.) of an ethylene (partially propylene) -carbon monoxide copolymer resin was added to 100% by weight. Composition C-4 in which 3 parts by weight of B-3 and 2 parts by weight of B-4 are mixed; A-6 is added to 80% by weight, and a polybutylene terephthalate copolymer resin (PEST-1: alcohol component) is added. 1,4 Butanediol 80 mol%, triethylene glycol 19 mol%, polytetramethylene glycol 1 mol% copolymerized: crystal melting point 220 ° C., crystallinity 40%) 20% by weight added 100 weight A composition in which 3 parts by weight of B-6 and 2 parts by weight of B-7 are mixed.

The packaging test was carried out by placing rice in a commercially available microwave oven heating porcelain (or plastics) container, placing curry on it, and changing the heating time in a microwave oven with a sample repetition rate of n = 5. First, each box containing the above film was wrapped. As a result, as for the pullability from the box, the films of Examples 1 and 2 could be pulled out accurately in a predetermined amount with an appropriate resistance as in the case of the above-mentioned commercially available vinylidene chloride resin (hereinafter abbreviated as commercially available PVDC). However, the film of Comparative Example 1 (hereinafter referred to as ratio 1) was not preferable because it came out of the box too much or static electricity was generated and stuck to various places. Comparative Example 2 (hereinafter, similarly, represents the ratio 2) is too sticky apparent film of leads One Kutsu part of the box, or clinging to the hand, there Ide trouble. Next, regarding the cutability of the blade attached to the box, the films of Examples 1 and 2 were comfortable to cut and had good blade cutability, as in the case of commercially available PVDC products. Ratio 1 is because the elastic modulus of the film is too high and there is almost no adhesion, so it is difficult for the film to be fixed to the holding part of the box tip at the time of cutting, and the roll is blocked and difficult to pull out, or it shifts locally. It was difficult to bite into the cutting edge, and the cut surface came off the cutting edge and tore diagonally, resulting in extremely poor cutability. In addition, the packaging is poor (Italy film between one Gaku' by static electricity, somewhere selfish or stick to the place, and the bottom line container That said, and without any adhesion to film each other, will spread the film packaging did not become can not) useless fixed, the ratio 2, cut resistance has been Tsu Ha felt somewhat unsatisfactory too soft compared to the embodiment, sticky, immediately after the cut, is poor stretched retention of the film, evil Katsuta and Tsu instead of overlapping properties.

Next, at the time of heating in a microwave oven, a ratio of 1 is the film tends to leak water vapor does not contact as described above, tends to be local heating, easy to spill the contents are outside, the taste of the food be made badly Tsu want It was. Ratio 2 has high shrinkage of the film, the close contact part is displaced, the film and the container are easily peeled off, the contact part with the contents (curry) is torn when the heating time is a little long, and plastics (PP; polypropylene) In the case of a container made of), it was found that it was partially welded to the container and soiled the container after the film was peeled off. None of these defective phenomena of Examples 1 and 2 were present, the film could be packaged and heated well, the film could be easily peeled off and removed later, and the taste of the cooked product was good, which was within the preferable range of the present invention. It was a characteristic.

これらのフイルムについて、実施例１の場合と同様に包装テストを実施した、その結果引き出し性、カット性、展張性、オーバーラップ性、密着性、加熱性、その他を順次、テストしたが、特に問題は、見られ無く、実施例１，２の場合と同様に本発明の好ましい範囲内であった。

These films were carried out in the same manner as in the packaging test as in Example 1, resulting drawer properties, cuttability, stretched resistance, overlap, adhesion, heat resistance, and other sequential has been tested, in particular the problem Was not seen and was within the preferable range of the present invention as in the cases of Examples 1 and 2.

Claims (2)

A resin composition (C) containing 1 to 20 parts by weight of a liquid additive (B) with respect to 100 parts by weight of a resin (A) mainly composed of a glycolic acid (PGA) -based aliphatic polyester resin having a crystal melting point of 120 to 250 ° C. ), The film has a crystallinity of 15 to 70%, a tensile elastic modulus of 20 to 150 kg / mm ² , a heat shrinkage rate of X% at 100 ° C., and a heat shrinkage stress of Yg / mm ^2. , in the range of relation of the following formulas (1) to (3), adhesion resistant wrap film heat resistance, characterized in der Rukoto than 120 ° C..
Equation (1) Y ≦ (1400-20X) / 3
Equation (2) 2 ≤ X ≤ 45
Equation (3) 5 ≤ Y ≤ 350 The liquid additive (B) is an aliphatic alcohol, an alicyclic alcohol, at least one alcohol selected from these polyhydric alcohols and condensed polymers thereof, the alcohol component and an aliphatic fatty acid, an aliphatic or aromatic poly. Esters with at least one fatty acid selected from valent carboxylic acids, esters of aliphatic hydroxycarboxylic acids with alcohols and / or fatty acids, and modifications of these esters, polyoxyethylene alkyl ethers and esters thereof, oligomers of aliphatic polyesters. The adhesive heat-resistant wrap film according to claim 1 or 5, wherein the adhesive heat-resistant wrap film comprises at least one plastic agent selected from the group consisting of mineral oil, liquid paraffin, and a low polymer composed of a saturated hydrocarbon compound.