JPH106356A - Polyolefin injection-molded object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently satisfy the demand of oxidative deterioration resistance and to also satisfy said demand even under environment containing water by compounding a specific phenol compd. component with polyolefin in a specific ratio. SOLUTION: 0.01-3 pts.wt. of a phenol compd. component represented by formula I is compounded with 100 pts.wt. of polyolefin. In the formula I, X is a group represented by formula II (wherein R1 and R4 may be same or different and are respectively a 1-8C alkyl group and R2 , R3 , R5 and R6 may be same or different and are respectively a hydrogen atom or a 1-8C alkyl group). Since the phenol compd. having a specific structure compounded with polyolefin is a hindered phenol compd. having a hindered phenol compd. having a hindered phenyl ester structure, the long-term oxidative deterioration preventing effect of polyolefin is shown even under environment containing water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyolefin injection molded article. More specifically, the present invention relates to an injection molded article of a polyolefin resin having excellent durability and bleed resistance even in an environment where a solvent such as water is present.

[0002]

2. Description of the Related Art Polyolefins have a problem in that they undergo oxidation during processing and use and their quality deteriorates. For this reason, various antioxidants have conventionally been developed and incorporated into materials for the purpose of preventing oxidative deterioration. Among them,
Hindered phenol compounds (for example, Japanese Patent Publication No. 38-1)
70164, JP-B-39-4620, JP-B-39-
No. 21140, JP-B-42-9651, JP-A-62-965
No. 30134) are particularly useful for preventing oxidative deterioration of synthetic polymer materials such as polyolefins, and are currently in practical use. However, when a material stabilized by various antioxidants is used in an environment where water is present, the effect of preventing oxidation deterioration is significantly reduced, and the quality of the polyolefin resin is significantly reduced. . Conventionally, it has been considered that such a cause is due to the fact that the antioxidant in the synthetic polymer material is extracted with water or extracted after being hydrolyzed. Therefore, materials used in an environment where water is present generally do not contain an ester structure and have a high molecular weight, rigid antioxidant to prevent extraction or hydrolysis by water. A method of compounding an agent has been performed (see Japanese Patent Application Laid-Open No. 2-265939).

[0003]

However, the compounding of an antioxidant having such a special structure does not sufficiently satisfy the required resistance to oxidation deterioration, so that it may be used in an environment where water is present. There is a need for antioxidants that are also particularly effective in preventing oxidation.

[0004]

The present inventors have repeatedly studied the mechanism of oxidative deterioration of polyolefin, the mechanism of preventing oxidative deterioration, and the interaction with water. The present inventors have found that they have excellent ability to prevent oxidative deterioration, and in particular, can exert a remarkable effect even when used in an environment where water is present, and have completed the present invention. That is, the polyolefin injection molded article of the present invention is made of polyolefin 10
It is characterized in that 0.01 to 3 parts by weight of a phenol compound component represented by the following general formula [1] is mixed with 0 part by weight. General formula [1] [Wherein, X represents a group represented by the following general formula [2]. General formula [2]

[0005]

Embedded image

(Wherein R ₁ and R ₄ may be the same or different and each represents an alkyl group having 4 to 8 carbon atoms;
R ₂ , R ₃ , R ₅ , and R ₆ may be the same or different and each represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. )]

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

[I] Polyolefin injection molded article (1) Polyolefin resin composition (a) Constituent polyolefin resin Various polyolefin resins are used as the polyolefin resin used as the raw material of the polyolefin injection molded article of the present invention. can do. Specific examples of such polyolefin resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, polypropylene, poly-α-olefins such as polybutene-1, ethylene-propylene random or block copolymers, ethylene-butene- (1) α-olefin copolymers such as random copolymers, polyolefins such as copolymers of poly-α-olefins with other monomers such as maleic anhydride-modified polypropylene, and polyolefins such as mixtures thereof, and the like. it can. Among these, the effects of the present invention can be remarkably exhibited by using polypropylene. In particular, as the polypropylene,
Propylene homopolymer or propylene and ethylene, butene-1, pentene-1, hexane-1,4-
Α-olefins such as methyl-pentene-1, unsaturated carboxylic acids and derivatives thereof such as acrylic acid, ethyl acrylate and maleic anhydride; vinyl esters such as vinyl acetate; unsaturated aromatic compounds such as styrene and methylstyrene; And a random, block, or graft copolymer.

Phenol compound In the polypropylene resin composition of the present invention, the phenol compound blended in the polypropylene resin is a phenol compound represented by the following general formula [I]. General formula [1] [Wherein, X represents a group represented by the following general formula [2]. General formula [2]

[0009]

Embedded image

(Wherein R ₁ and R ₄ may be the same or different and each represents an alkyl group having 1 to 8 carbon atoms;
R ₂ , R ₃ , R ₅ , and R ₆ may be the same or different and each represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. )] Specific examples of each symbol represented by the phenol compound represented by the general formula [I] are as follows. As R ₁ and R ₄ , an alkyl group having 1 to 8, preferably 1 to 5 carbon atoms, each of which is linear,
It may be either branched or cyclic. Specifically, methyl, ethyl, n-propyl, isopropyl, n
-Butyl group, isobutyl group, sec-butyl group, ter
t-butyl group, pentyl group, isopentyl group, sec-
Pentyl group, tert-pentyl group, 2-methylbutyl group, n-hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, cyclohexyl group, heptyl group, n-octyl group, isooctyl group, sec-octyl group, Examples include a tert-octyl group and a 2-ethylhexyl group. R ₂ , R ₃ , R ₅ and R ₆ each represent a hydrogen atom, a methyl group,
Ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, 2-methylbutyl Group, n-hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, cyclohexyl group, heptyl group, n-octyl group, isooctyl group, sec-octyl group, tert-octyl group, 2-ethylhexyl group, etc. An alkyl group having 1 to 8, preferably 1 to 5 carbon atoms, which may be linear, branched or cyclic.

X in the compound of the general formula [1]
Is not necessarily the same for all three,
Usually, it is preferable that they are the same. The general formula [1]
Is usually 1,1,3-tris (2-methyl-
4-hydroxy-5-tert-butylphenyl) butane or 1,1,3-tris (3-methyl-4-hydroxy-5-tert-butylphenyl) butane and the like;
5-di-tert-butyl-4-hydroxyphenylpropionic acid or 3-methyl-5-tert-butyl-4
It is obtained by a chemical reaction with -hydroxyphenylpropionic acid or the like or the corresponding propionyl chloride, etc., and is a crude product of the reaction (a compound produced as a by-product in the reaction may be mixed at an arbitrary ratio). It may be.

Specific examples of the phenol compound represented by the general formula [1] include 1,1,3-tris [2-methyl-4- (3,5-di-tert-butyl-4-hydroxyphenyl). Propionyloxy) -5-tert-butylphenyl] butane, 1,1,3-tris [3-methyl-4- (3,5-di-tert-butyl-4-hydroxyphenylpropionyloxy) -5-butylphenyl ] Butane, 1,1,3-tris [2-methyl-4-
(3-methyl-5-tert-butyl-4-hydroxyphenylpropionyloxy) -5-tert-butylphenyl] butane, 1,1,3-tris [3-methyl-
4- (3-methyl-5-tert-butyl-4-hydroxyphenylpropionyloxy) -5-tert-butylphenyl] butane. These can be used alone or in combination of two or more.

The feature of the phenol compound represented by the general formula [1] is that it is a hindered phenol compound having a hindered phenyl ester structure. That is, in an environment where water is present, hindered phenol exhibits an antioxidant effect at the beginning of use, and the hindered phenyl ester is deteriorated by the action of water during use.
Since hindered phenol is newly generated and the ability to prevent oxidative deterioration can be continuously exhibited, a long-term effect of preventing oxidative deterioration can be exhibited even in an environment where a solvent such as water is present.

(B) Amount ratio In the polyolefin injection molded article of the present invention, the amount of the phenolic compound represented by the general formula [1] blended in the polyolefin resin is 0.01 to 100 parts by weight of the polypropylene resin. 3 parts by weight, preferably 0.01 to
1 part by weight, particularly preferably 0.03 to 0.7 part by weight. If the amount of the phenol compound is less than the above range, the effect of preventing deterioration is insufficient. On the other hand, when it exceeds the above range, defects such as bleeding and discoloration occur.

(C) Additional Component (Optional Component) The polyolefin injection molded article of the present invention essentially comprises the above-mentioned polyolefin resin and the above-mentioned general formula [1] component. Thus, additional components other than these may be added to such an extent that the effects of the compound of the present invention are not significantly impaired. Specific examples of such additional components include antioxidants other than the general formula [1], such as other phenolic antioxidants, phosphorus antioxidants, light stabilizers, ultraviolet absorbers, Deactivator,
Or, flame retardants, ionic, non-ionic antistatic agents,
Lubricants such as silicone oil and amide, processing aids, neutralizers,
Nucleating agents, plasticizers, inorganic and organic pigments, dispersants, fillers such as talc, calcium carbonate, barium sulfate, foaming agents, peroxides, fluorescent whitening agents, and resins other than the polyolefin resin , Rubber and the like. Among the additional components, in particular, a sulfur-based antioxidant, or a hindered amine-based stabilizer is further used in combination with the compound of the present invention, as in the case of using with a normal phenol-based antioxidant. Excellent effects of the present invention can be exhibited.

Sulfur-based antioxidants Examples of the sulfur-based antioxidants include dialkyl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, and dialkyl thiodipropionate such as didocosyl thiodipropionate. Dialkyl disulfides such as pionates and distearyl disulfide; alkylthiopropionic acids such as tetrakis [methylene (laurelthiopropionate)] methane and tetrakis [methylene (stearylthiopropionate)] methane; and polyhydric alcohols And the like,
It is not limited to these. These can be used alone or in combination of two or more. The compounding amount of the sulfur-based antioxidant is preferably 0.1 to 10 times, particularly preferably 1 to 7 times the amount of the phenol compound represented by the general formula [1].

Hindered amine stabilizers Hindered amine stabilizers include, for example, N, N '
-Bis (3-aminopropyl) ethylenediamine-2,
4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-
1,3,5-triazine condensate, poly [｛6- (1,
(1,3,3-tetramethylbutyl) imino-1,3,5
-Triazine-2,4-diyl} (2,2,6,6-
Tetramethyl-4-piperidyl) imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}], dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2 succinate , 2,6,6-tetramethylpiperidine polycondensate, poly- {2-N, N'-
Di (2,2,6,6-tetramethyl-4-piperidyl)
Hexanediamine-4- (N-monophorino) symtriazine}, but is not limited thereto. These can be used alone or in combination of two or more. The amount of the hindered amine-based stabilizer is preferably 0.2 to 5 times, particularly preferably 0.3 to 4 times the amount of the phenol compound represented by the general formula [1].

Other antioxidants The other antioxidants include 2,6-di-
t-butyl-4-methylphenol, 4,4'-thiobis (3-methyl-6-t-butylphenol), 4,
4'-butylenebis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4-methyl-6-
t-butylphenol), 2,2'-ethylidenebis (4,6-di-t-butylphenol), d, l-α-
Hindered phenol compounds such as tocopherol, tris (mixed-mono and di-nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,4-di-t-) Butylphenyl) pentaerythritol-diphosphite, tetrakis (2,4-di-t-butylphenyl) 4-4 '
And aromatic phosphorus compounds such as -biphenylene-diphosphonite. Even if these are one kind,
More than one species can be used. Preferred amounts of the above-mentioned other antioxidants include the polyolefin resin 1
Generally, 0.01 to 3 parts by weight is added to 00 parts by weight.

Filler Examples of the filler include talc, mica, glass fiber and the like. These can be used alone or in combination of two or more. The preferable amount of the filler is generally 0.1 to 50 parts by weight based on 100 parts by weight of the polyolefin resin.

Resins / Rubber The resins and rubbers include polyamide, polyester,
Polystyrene, ethylene-propylene copolymer rubber,
Ethylene-butene-based copolymer rubber can be used. These can be used alone or in combination of two or more. The preferred amount of the resin or rubber is generally 1 to 40 parts by weight per 100 parts by weight of the polyolefin resin.
It is blended by weight.

(2) Injection molding The injection molding of the polyolefin resin for injection molding the above-mentioned polyolefin resin composition can be carried out in the same manner as the generally known injection molding method of polyolefin resin. Examples of the injection molding method include a sandwich injection molding method, a gas assist injection molding method, an injection compression molding method, and a multicolor injection molding method, in addition to a general injection molding method.

[II] Applications The shape of the polyolefin injection molded article obtained by the above-mentioned injection molding is substantially determined by its use, and examples include injection molded articles of polyolefin resins of various shapes. Injection molded products of polyolefin resin, which can particularly receive the effects of the present invention, products that come into contact with solvents such as water, aqueous surfactant solution, acidic aqueous solution, alkaline aqueous solution, seawater, domestic wastewater, ethylene glycol, propylene glycol, In particular, use in contact with water, and furthermore, a molded article in contact with water at a high temperature are preferable. Specific examples of such suitable products include outer tubs of washing machines, tanks, dewatering tubs, rotors,
Dishwasher, heater humidifier, hot water supply / drainage equipment parts, heating equipment equipment, jars, pots, rice cooker members, water storage tanks,
Examples include bathtub parts such as flow tubs, drainage tanks such as sewage, flush toilet tanks, piping parts, food containers, tableware, reserve tanks for automobiles, brake oil tanks, washer tanks, and battery cases. These injection-molded articles can effectively exhibit the effects of the present invention, such as durability in a solvent and bleed resistance, and thus can enhance commercial value.

[0023]

EXAMPLES In order to explain the present invention in more detail, the following will be described.
The present invention will be specifically described with reference to Examples and Comparative Examples. Example 1 MFR 30 g / 10 min (JISK6758, 230
C), 100 parts by weight of a propylene / ethylene block copolymer having an ethylene content of 3% by weight were blended with the compounds in the amounts shown in Table 1 and thoroughly mixed by a mixer, and then extruded at a cylinder temperature of 230 ° C. and a cylinder diameter of 30 mm. The mixture was melt-kneaded and granulated. 24 pellets obtained
Injection molding was performed at a temperature of 0 ° C. to prepare an injection molded test piece having a thickness of 2 mmt. At the time of injection molding, 0.2% by weight of a carbon black pigment was dry-blended to be colored and provided for molding. The obtained injection molded test pieces were subjected to durability and bleed tests. That is, a sample of 20 × 60 × 2 mmt was cut out from the injection molded test piece, and the sample was placed in a stainless steel pressure-resistant tube having an inner diameter of 27 mm and a height of 110 mm containing 10 cc of tap water, and heated in a 150 ° C. oven. Warm and release every 24 hours to determine the durability by measuring the time until the injection molded test piece becomes brittle. Also, at 96 hours, the glossiness of the surface was determined according to the following criteria. Judgment was made as a measure of the degree of bleed. The gloss of the surface was determined as follows: ：: almost no bleeding ○ ^- : slightly to some extent Δ: somewhat to some extent ×: clear bleeding The results obtained are shown in Table 1.

The details of the compounds indicated by the abbreviations in the table are shown below. Compound A1 of the formula [1] : 1,1,3-tris [2-methyl-4- (3,
5, -Di-tert-butyl-4-hydroxyphenylpropionyloxy) -5-tert-butylphenyl] butane A2 1,1,3-tris [3-methyl-4- (3,
5, -Di-tert-butyl-4-hydroxyphenylpropionyloxy) -5-tert-butylphenyl] butanephenol antioxidant B1: 1,3,5-trimethyl-2,4,6-tris (3 5-di-t-butyl-4-hydroxybenzyl)
Benzene (trade name “IRGANOX 133” manufactured by Ciba-Geigy)
0 ") B2: tetrakis [methylene-3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate] methane (trade name “IRGANOX 101” manufactured by Ciba-Geigy)
0 ") B3: 3,9- [2- {3- (3-t-butyl4-hydroxy-5-methylphenyl) propionyloxy}-
1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane (Adeka Stab AO80)

Sulfur-based antioxidant C1: tetrakis [methylene (laurylthiopropionate)] methane (Cypro Kasei Co., Ltd. “Seanox 412S”) C2: distearylthiodipropionate (Yoshitomi Pharmaceutical “DSTP Yoshitomi”) hindered amine Stabilizer D1: N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,
6,6-pentamethyl-4-piperidyl) amino] -6
-Chloro-1,3,5-triazine compound (Chiba Geigy “Kimasorb 119FL”)

Phosphorus antioxidant E1: Tris (2,4-di-t-butylphenyl) phosphite (Irgafos 168, Ciba-Geigy) Neutralizer F1: Calcium stearate (Kosaic "Ca-st")

[0027]

[Table 1]

[0028]

As described above, in the polyolefin injection molded article of the present invention, the phenol compound having a specific structure mixed in the polyolefin resin as a raw material is a hindered phenol compound having a hindered phenyl ester structure. Therefore, in an environment where water exists,
Hindered phenol exhibits an antioxidant effect in the early stage of use, and if the hindered phenyl ester is altered by the action of water during use, hindered phenol is newly generated, and the ability to prevent oxidation deterioration can be continuously exhibited. Therefore, even when used in an environment where water is present,
A polyolefin injection molded article which can exhibit a long-term effect of preventing the polyolefin resin from being oxidatively degraded and has excellent durability and bleed resistance can be obtained.

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[Procedure amendment]

[Submission date] July 8, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

Embedded image (Where R ₁ and R ₄ may be the same or different and each represents an alkyl group having 1 to 8 carbon atoms, and R ₂ , R ₃ ,
R ₅ and R ₆ may be the same or different and each represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. )]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

Embedded image

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

(Wherein R ₁ and R ₄ may be the same or different and each represents an alkyl group having 1 to 8 carbon atoms;
R ₂ , R ₃ , R ₅ , and R ₆ may be the same or different and each represent an alkyl group having 1 to 8 carbon atoms. )

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009]

Embedded image

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 23/00 LBZ C08L 23/00 LBZ C09K 15/08 C09K 15/08 // B29K 23:00 ( 72) Inventor Kimiho Kosegaki 1 Toho-cho, Yokkaichi-shi, Mie Prefecture Inside Yokkaichi Research Institute, Mitsubishi Chemical Co., Ltd. (72) Inventor Shigenobu Kawai 1-Tohocho, Yokkaichi-shi, Mie Mitsubishi Chemical Corporation Yokkaichi Comprehensive Research (72) Inventor Tatsuo Kobayashi 1 Toho-cho, Yokkaichi-shi, Mie Prefecture Inside Yokkaichi Research Institute, Mitsubishi Chemical Corporation

Claims (4)

[Claims] An injection molded article of a polyolefin resin, wherein the polyolefin resin is mixed with 0.01 to 3 parts by weight of a phenol compound component represented by the following general formula [1] per 100 parts by weight of the polyolefin. A polyolefin injection-molded article characterized by comprising: General formula [1] [Wherein, X represents a group represented by the following general formula [2]. General formula [2] (Where R ₁ and R ₄ may be the same or different and each represents an alkyl group having 4 to 8 carbon atoms, and R ₂ , R ₃ ,
R ₅ and R ₆ may be the same or different and each represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. )] 2. The polypropylene composition for coating steel pipes according to claim 1, wherein the phenolic compound represented by the general formula [1] is used in combination with another antioxidant. 3. The polypropylene composition for coating steel pipes according to claim 2, wherein the other antioxidant is a sulfur-based antioxidant. 4. The polypropylene composition according to claim 2, wherein the other antioxidant is a hindered amine stabilizer.