JPS5879044A - Resin composition for polypropylene film having improved fog resistance - Google Patents

Abstract

PURPOSE:A composition for providing a film for packing foods, haing improved low=temperature fog resistance, not raising ingredients to the surface, obtained by blending polyhydric alcohol fatty acid mono ester and diester with a specific alcohol and a specified diethanolamine compound. CONSTITUTION:(A) 100pts.wt. polypropylene is blended with (B) 0.2-0.5pts.wt. mixed ester of polyhydric alcohol fatty acid esters in a weight ratio of monoester to diester of (80:20)-(30:70), (C) 0.1-0.3pts.wt. compound shown by the formula R'OH (R<1> is 8-22c alkyl or acryl)or by the formula R<2>-(OCH2CH2)nOH (R<2> is 8-22C aromatic residue, n=4-10), and (D) 0.05-0.3pts.wt. compound shown by the formulaI(R<3> is 8-22C alkyl or acyl).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition for polypropylene film that has excellent antifogging properties at low temperatures.

Polypropylene film has excellent chemical, physical,
Widely used for its mechanical properties.

However, when polypropylene film is used as a packaging film for meat, fresh fish, fresh vegetables, etc.,
Due to the hydrophobic nature of polypropylene, water droplets adhere to the inside of the film, causing cloudiness and opacity. Additionally, moisture adhering to the inside of the film may have an adverse effect on the food inside. Many proposals have already been made to impart antifogging properties to polypropylene films. However, according to studies conducted by the present inventors, although some of these are found to be effective in terms of antifogging properties at room temperature, the antifogging effects are insufficient at low temperatures (about 0°C to 5°C). When packaging meat, fresh fish, fresh vegetables, etc., these packages are often stored at low temperatures, so there has been a desire to develop polypropylene films that have good antifogging properties at low temperatures.

According to Japanese Patent Publication No. 38-4174, polyolefin contains fat and
Proposals have been made to improve antifogging properties by mixing fatty acid monoglycerides or mixtures of monoglycerides and diglycerides that form In some cases, the monoglyceride in the mixture is the active ingredient; in other words, it is the monoglyceride in the mixture that gives the polyolefin film its non-cloudy surface properties.'' There is. However, our research has revealed that monoglycerides do not have an anti-fogging effect at low temperatures if used incorrectly.With this in mind, we conducted extensive research and found that monoglycerides do not have an anti-fogging effect at low temperatures. Monoester, polyhydric alcohol fatty acid ester, general formula RI 0H (R
1: Alkyl group or acyl group consisting of 8 to 22 carbon atoms) or R2 (0(jH2CH2)nOH (R'': aromatic residue consisting of 8 to 22 carbon atoms, n = integer of 4 to 10) A polypropylene film having a good low-temperature antifogging effect and without any embossment of the crosstalk mixture can be obtained by using a specific amount of a compound represented by the following formula (and alkyl group or acyl group) under specific conditions. This discovery led to the present invention.

That is, the present invention provides a resin composition for a polypropylene film with excellent low-temperature antifogging properties, characterized by comprising the following (6) to (to).

(6) polypropylene (100 parts by weight) polyhydric alcohol fatty acid ester, a mixed ester consisting of monoester: diester = 80:20-30 (weight ratio) 0.2-0.5 parts by weight (0
General formula R1-0H (where R1 is an alkyl group or acyl group consisting of 8 to 22 carbon atoms) or R'' (0OH2
CH,) nOH (where Hz is an aromatic residue having 8 to 22 carbon atoms, n = an integer of 4 to 10) 0.1 to 0.3 parts by weight An alkyl group or acyl consisting of 8 to 22 parts by weight The compound represented by the group 0.05 to 0.3 electric storage unit.

Hereinafter, the constituent elements of the present invention will be explained separately.

The polypropylene (4) used in the present invention may be either a homopolymer or a copolymer with other α-olefins. The manufacturing method is not particularly limited, but typically includes, for example, 'rici'.

TICjRs-hkAOI), slb Louis triMyC
etc. (with one or more transition metal catalysts such as a carrier catalyst supporting a D-carrier KT1 compound)
．． A4Et2Cn.

A catalyst system consisting of one or more organic i-catalysts such as AfiEt2H or Al1-1so-Bu3 and, if necessary, one or more third components is used, and is usually heated at 40 to 90°C. manufactured at a temperature of Other α-olefins used in copolymers include ethylene, butene-1, isobutyne, pentene-1
1, hexene-1,4-methylpentene-1, and styrene, one or more of these.

In the polyhydric alcohol fatty acid ester of 03) used in the present invention, the polyhydric alcohols include ethylene glycol, propylene glycol, chrycerin, sorbitol, polyglycerin, pentaerythritol, dipentaerythritol, etc., and the fatty acids include: Examples include butyric acid, caproic acid, caprylic acid, lauric acid, myristic acid, balmitic acid, oleic acid, stearic acid, behenic acid, and mixed fatty acids such as coconut, soybean, and beef tallow.

In the present invention, the polyhydric alcohol fatty acid ester is
Monoester and diester toca 80:20~ao:
It is an essential condition that a mixture with a weight ratio of 70% is used. The reason for this is not clear, but even if each is used alone or as a mixture, the low-temperature antifogging effect is insufficient outside this range. Further, up to 15% by weight of triester may be mixed in the mixture of monoester and diester.

In the present invention, (C) has the general formula R1-OH (wherein R1 is an alkyl group or acyl group having 8 to 22 carbon atoms)
Examples of the compound represented by include stearyl alcohol, oleyl alcohol, lauryl alcohol, cetyl alcohol, tesyl alcohol, myristyl alcohol, and behenyl alcohol. Also general formula %
Examples of the aromatic residue of the formula %22 (an integer of n-4 to 10) include ethylene oxides of alkylphenols such as octylphenol, nonylphenol, tecylphenol, and dodecylphenol.
0 mole adducts are mentioned.

The compound represented by (R3 is an alkyl group or acyl group having 8 to 22 carbon atoms) is a nonionic surfactant generally called alkylgetanolamine or alkylgetanolamide, such as N,N '
-bis(2-hydroxyethyl)stearylamine, N
, N'-bis(2-hydroxyethyl)oleylamine, N,N'-bis(2-hydroxyethyl)laurylamine, N,N'-bis(2-hydroxyethyl)stearylamide, N,N'-bis( 2-hydroxyethyl)
These include oleylamide, N,N'-bis(2-hydroxyethyl)oleylamide, etc., and these may be used alone or in combination.
Mixtures of 0 or more species are used.Knead with 100 parts by weight of polypropylene (A) (
B) ~The amount of plow used is @0.2~0.5% by weight ((5) 0.1~0.3% by weight (D), 0.05~0.3% by weight, and the amount used in the above ( In addition to the conditions regarding (O and (B)),
Only when (b) is used within this range, the low-temperature antifogging effect aimed at by the present invention can be satisfactorily obtained.

If the amount of (6) to (b) used is less than the above range, the low-temperature antifogging effect will be insufficient, and if used in excess of the above range, embossment will occur on the film surface after film formation, resulting in poor transparency. becomes defective, and foaming occurs due to moisture absorption.

In addition, in the present invention, (B) to (B) can be added to polypropylene by adding each of them directly to polypropylene, or after manufacturing a master patch in which (uniformly) to (B) are added at a high concentration in advance. , it may be added to polypropylene in an amount within the above range.

The polypropylene film obtained by the present invention is transparent and has excellent low-temperature antifogging effects, and there is no problem of toxicity of the additives used, so it is suitable for food packaging.

Furthermore, antioxidants, slip agents, anti-blocking agents, ultraviolet absorbers, nucleating agents, etc. may be added to the polypropylene film of the present invention, if necessary.

The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Examples 1 to 3 Comparative Examples 1 to 5 Propylene-ethylene random copolymer (A) (ethylene content 4.8%, intrinsic viscosity measured in tetralin at 230°C [9) = 1.56] listed in Table 1 Predetermined amounts of the compounds (B) to (B) were added, mixed in a Henschel mixer, and pelletized in an extruder at 220°C. This pellet was made into a film with a thickness of 30 μm using an extruder equipped with a 40 mm T-die.

After storing this film in a constant temperature and humidity machine at 23°C and 65°C for 2 days, it was made into a bag of the same size and filled with an equal amount of fresh vegetables, which was then stored at 5°C for 1 hour. The condition of water droplets on the inner surface of the film was observed. (Anti-fogging property at 5℃) In addition to the above, water droplets on the inner surface of the film when a film that has been stored for 2 days in a constant temperature and humidity chamber at 23℃ and humidity of 65℃ is placed over the mouth of a pot containing hot water at 80℃. The condition was observed. (Anti-fogging property at 80°C).

The results are shown as follows: ◎ No water droplets, transparent ○ Large water droplets adhered to some areas, slightly transparent Δ Water droplets adhered to a large extent, translucent X Water droplets adhered to the entire surface, opaque.

Furthermore, the extrusion of additives from the film was observed after the film was formed and stored in a constant temperature and humidity machine at 23° C. and 65° C. for 2 days.

Claims (1)

[Scope of Claims] A resin composition for polypropylene film with excellent low-temperature antifogging properties, characterized by comprising the following (6) to (b): (6) Polypropylene 100 weight i 1 part ■ Polyhydric alcohol fatty acid ester Yes, monoester nitrogen ester h-8o: 20-30 nia 0 (weight ratio)
Mixed ester consisting of 0.2 to 0.5 parts by weight (Q
General formula R1-OR (where R1 is an alkyl group or acyl group consisting of 8 to 22 carbon atoms) and the father is R''-(OCH
2CH2) non (However, BtFi is an aromatic residue consisting of 8 to 22 carbon atoms, an integer Jt of n = 4 to 1o) 0.1 to 0.3 parts by weight Alkyl group or acyl having a prime number of 8 to 22 Compound represented by group) 0.05 to 0.3 parts by weight