JPH0352960A - Molded article for colored food - Google Patents

Abstract

PURPOSE:To obtain an odorless molded article free from discoloration even in contact with a colored food such as vegetable or fruit and suitable for seal vessel, vessel for heating with an microwave oven, etc., by blending a thermoplastic resin with a specific antioxidant at a specific amount. CONSTITUTION:(A) 100 pts.wt. thermoplastic resin (e.g. polyolefin or butadiene resin) is blended with (B) 0.01 to less than 0.1 pts.wt., preferably 0.02-0.08 pts.wt. compound [e.g. n-octadecyl-beta-(4'-hydroxy-3',5'-di-tert.-butylphenyl)propionate] selected from both hindered phenolic antioxidant having >=300 molecular weight or single hindered phenolic antioxidant having >=600 molecular weight.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to molded articles for colored foods that are unlikely to discolor even when they come into contact with colored foods such as vegetables and fruits. (Prior Art) Thermoplastic resins are widely used in food containers and utensils because they are inexpensive and have excellent molding properties. However, molded products made of thermoplastic resin may deteriorate due to contact with colored foods such as vegetables and fruits such as spinach and Chinese cabbage.
Discoloration occurs. In order to solve this problem, for example,
-36 1 50 and JP-A-81-113632 disclose polypropylene containing additives such as paraoxybenzoic acid and higher fatty acid alcohol, but the effects are not sufficient and further improvements are desired. In general, the causes of discoloration of molded products due to colored foods such as fruits and vegetables and their processed products include discoloration due to the pigments contained in them, discoloration due to rotting vegetables, discoloration due to food coloring agents, and Coloring may be caused by interactions between various additives and pigments, but this is not clear. Additionally, thermoplastic resins are generally prone to thermal oxidation during processing and use, as well as deterioration of light resistance due to their chemical structure. Therefore, antioxidants and light stabilizers are usually added to suppress deterioration. Although it is possible to obtain a product that can withstand practical use, does this antioxidant make the coloration from colored foods more pronounced? This has become a problem. (Problems to be Solved by the Invention) An object of the present invention is to provide a molded article for colored foods that is unlikely to discolor due to contact with such colored foods and is odorless. (Means for Solving the Problems) The present invention provides 100 parts by weight of a thermoplastic resin with a molecular weight of 300 parts by weight.
Both of the above hindered phenolic antioxidants or minutes. A compound selected from single hindered phenolic antioxidants having a molecular weight of 600 or more. This is a colored food molded product characterized by containing less than 1 part by weight. The double hindered phenol antioxidant mentioned here refers to a carbon atom on both sides of the carbon atom to which the hydroxyl group of phenol is bonded, which contains hydrocarbon groups, such as C+-s alkyl groups, cycloalkyl groups, or aryl groups. A single hindered phenolic antioxidant is one in which a hydrocarbon group is substituted on the carbon atom adjacent to the carbon atom to which the hydroxyl group is bonded. Thermoplastic resins used in the present invention include butadiene resin, polystyrene, AS resin, ABS resin, polyphenylene ether, polyacrylonitrile, fluororesin, polymethacrylstyrene, meccrylic resin, nylon, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, Examples include polyvinyl alcohol, polyacecool, polyallylsulfone, polyarylate, droxybenzoic acid polyester, polyvinyl chloride, polyvinylidene chloride, and polyolefin. The above-mentioned polyolefins are α-olefin homopolymers such as ethylene, brobylene, l-butene, 1-bentene, l-hexene, 4-methylpentene-1, α-olefins, or combinations of these α-olefins and other α-olefins. Random copolymers, block polymers, alternating polymers with copolymerizable monomers (vinyl esters such as vinyl acetate, unsaturated organic acids such as acrylic acid, maleic anhydride, ethyl acrylate, or their esters), This includes graft polymers, etc.
Specifically, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, very low-density polyethylene, brobylene homopolymer, brobylene-ethylene random and block copolymer, brobylene-1-butene copolymer Combination, brobylene-ethylene-1-
Contains butene copolymers, poly-4-methylpentene-1, etc. Preferred as food containers are polyolefins,
Particularly preferably, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene,
Examples include brobylene homopolymer, propylene-ethylene random and block copolymer, brobylene-1-butene copolymer, propylene-ethylene-1-butene copolymer, and the most preferred among them is propylene homopolymer. and brobylene-ethylene random and block copolymers. Specific examples of hindered phenolic antioxidants used in the present invention include (1) n-ocucdecyl-β-(4'-hydroxy-3
'5'-di-t-butylphenyl) propynate (2) Tetrakis[methylene-3- (3'.5'-di-7-butyl-4'-hydroxyphenyl)brobionate]methane (3) l, 3.5 -trimethyl-2.4.6-tris(
3.5-di-tert-butyl-4-hydroxybenzyl)benzene (4) Calcium (3.5-di-tert-butyl-4-hydroxy-pendylbenzyl monoethynoleph sulfate) (5) Triethylene glycol bis[3- (3-1-
Butyl-5-methyl-4-hydroxyphenyl)probionate] (6) 3,9-bis[1,1-dimethyl-2-{β-(
3-t-butyl-4-hydroxy-5-methylphenyl)probionyloxy}ethyl]-2.4.8.10-
Tetra-sized xasubilo[5.5]undecane(7)bis[3.3-bis(4'-hydroxy-3'-
t-butylphenyl)monoacid]glycol (8)N. N'-bis[3-(3.5-di-t-butyl-4-hydroxyphenyl)provinyl]hydrazine (9) 2.2'-oxamidobis[ethyl 3-(3.5-di-t-butyl-4-hydroxyphenyl)
-di-t-butyl-4-hydroxyphenyl) propynate] (10) 1.3.5-tris(3',5'-di-t-butyl-4-hydroxyphenyl)
-butyl-4'-hydroxybenzyl)-S-triazine-2.4.6 (IH,3H,5H)-}-lion (11)1.3.5-tris(4-t-butyl-3-hydroxy-2 .6-dimethylbenzyl)isocyanurate (12) 3. 5-di-t-butyl-4-hydroxyhydrocinnamic acid triester with 1,3.
Examples include 5-tris(2-hydroxyethyl)-s-triazine-2.4.6 (1, 3H, 5H) and the like. Preferably (1), (21.(6
) and (lO). The amount of component (A) added is 0.01 to 100 parts by weight of the thermoplastic resin.
It is less than 0.1 part by weight, preferably 0.02 to 0.08 part by weight. If it is less than 0.01 part by weight, the stability of the thermoplastic resin will be impaired, and if it is more than 0.1 part by weight, the problem of discoloration will increase, which is not preferable. In the present invention, when the following sulfur-based antioxidant (hereinafter referred to as component (B)) is combined with the above component (hereinafter referred to as component (A)), an even greater effect can be obtained. Specific examples of this component include (13) dilaurylthiodibrobionate (14) dimyristylthiodibrobionate (15)
) distearyl thiodiprobinate (6) lauryl thiodiprobinate (17) dioctadecyl disulfide (18) pentaerythritol tetra(β-lauryl thiodiprobionate) ester, etc. ．． Among them, the most suitable compounds are the above (
14) and (15). The blending amount of these components (B) is O-0.0 per 100 parts by weight of the thermoplastic resin.
It is 8 parts by weight. Excessive amounts are not only uneconomical but also
This causes problems with odor and bleed, making it undesirable as a molded product for food. A preferred amount is 0.01 to 0.3 parts by weight. In the present invention, in addition to these components, other additional components may be blended within a range that does not significantly enhance the effects of the invention. Lubricants such as fatty acid amides and silicone oils, antistatic agents such as fatty acid glycerin esters, amine-based or amide-based agents, inorganic fillers such as talc and barium sulfate, molecular weight regulators such as peroxides, foaming agents, organic or amide-based antistatic agents, etc. Examples include inorganic pigments, optical brighteners, ultraviolet absorbers, organic and silver ions, inorganic antibacterial agents such as copper ions, neutralizing agents, antacids, organic and inorganic nucleating agents, etc. It will be done. Furthermore, ethylene-butene rubber and ethylene-propylene rubber can be added, and the addition of these synthetic rubbers is particularly effective in improving low-temperature impact strength. The composition comprising these components used in the present invention can be manufactured by a conventional method. For example, the above components and other components as necessary are added to a thermoplastic resin powder, stirred and mixed in a Henschel mixer, and then melt-kneaded and extruded in an extruder to form pellets. after that,
This pellet is generally processed into the desired molded product using a molding machine such as injection molding, compression molding, sheet molding, blow molding, or vacuum forming, but a master batch containing highly concentrated additive components is used. Alternatively, it may be added to the molding process. Preferably, containers made by injection molding are preferred in terms of appearance and uniformity of thickness. Colored foods in the present invention include vegetables such as spinach, Chinese cabbage, cabbage, carrots, pickled plums, daikon radish, garland chrysanthemums, strawberries, lemons, and kelp, and foods with pigments such as curry and ketchup, as well as processed materials thereof. Refers to goods. Molded products include sealed containers, pickling barrels, tableware, lunch boxes, cups, bowls, colanders, containers for food transportation, microwave ovens, etc. used for heating and cooking, such as sealed containers used for transporting, storing, cooking, and pickling. Containers, bags, Saiichi burlap film, refrigerator interior containers, cutting boards, chopsticks, spoons, spatulas, scissors, spatulas, sink draining corners, sink drainboards, juicer parts, mixers, etc. It can be used as parts and appliances such as dishwasher parts. Particularly preferably, the effects of the present invention are greatly exhibited in sealed containers and cooking containers such as microwave ovens. (Example) Examples 1 to 7, Comparative Examples 1 to 3 Brobylene-ethylene block copolymer (MFR=1
0g/10 minutes, ethylene content = 5% by weight), the following components were blended in the amounts listed in Table 1 (% by weight), blended in a Henschel mixer, and then mixed in a 30mmφ extruder (
The mixture was kneaded at 240°C. The obtained pellets were put into an injection molding machine (260°C) and molded into 2mm thick x 7cm (vertical) x t
An injection container measuring tc+n (width) x 4.5 cm (height) was molded.

Pour the spinach juice blended into this container. Stored at 30°C for 5 days. After that, the contents were removed, washed with water, and the degree of discoloration of the container was visually determined. The results are shown in Table 1. The judgment criteria are as follows: 0: Almost no change observed 00: Only a slight change observed ○: Slight discoloration Δ Two distinct discolorations ×: Quite strongly discolored Also, this spinach juice After washing the molded products soaked in water, they were placed in an oven at 80°C for 1 hour with a lid on, and the odor was then evaluated. 0: Almost no odor 00: Slight odor ○: Odor but not bothersome Δ: Considerable odor ×: Strong odor Example 8.9, Comparative Example 4 Same as Example 1 except that curry juice was used. I tested the method. The results are shown in Table 1. (A) Component Compound (1) above Compound (2) Compound (6) Compound (7) // Compound (10) (B) Component Compound (13) above // (14) Other additives CAST: Calcium stearate TPNC: 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane BHT di-2,6-di-t-butylphenol (invention) As is clear from the above test results, the thermoplastic resin molded product having the composition of the present invention does not discolor even if it comes into contact with colored foods for a long time, and is suitable for colored food molded products, especially sealed containers and microwave heating. This solves the problem of a container for use.

Claims (1)

[Claims] 100 parts by weight of thermoplastic resin, both hindered phenolic antioxidants with a molecular weight of 300 or more, or a molecular weight of 600
A colored food molded article, characterized in that it contains 0.01 to less than 0.1 part by weight of a compound selected from the above-mentioned hindered phenolic antioxidants.