JPH0379648A - Polyolefin resin composition - Google Patents

Abstract

PURPOSE:To obtain a composition, composed of a polyolefin resin, specific phenolic compound and sulfur-based compound having >=2 sulfur atoms, excellent in heat aging resistance and useful as a material for automotive external trim material, hollow containers, sheet molded products, etc. CONSTITUTION:A composition obtained by blending (A) 100 pts.wt. polyolefin resin (propylene polymer is specially effective) with (B) 0.01-3 pts.wt., preferably 0.05-2 pt.wt. phenolic compound expressed by formula I and (C) 0.01-3 pts.wt., preferably 0.05-1 pt.wt. sulfur-based compound (e.g. compounds expressed by formulas II and III) having >=2, preferably >=3 sulfur atoms so as to provide 1:(0.5-20), especially 1:(0.5-6) ratio of the components (B):(C), preferably further adding an ultraviolet ray absorber, a hindered amine-based light stabilizer, a phosphorus-based antioxidant, etc., preferably mixing the components using a roll, Henschel mixer, etc., thereto and then pelletizing the resultant blend with an extruder.

Description

[Detailed Description of the Invention] [Background of the Invention] [Industrial Field of Application] The polyolefin resin composition of the present invention has excellent heat aging resistance and is useful as a material for automobile exterior materials, hollow containers, sheet molded products, etc. It is something.

<Prior art> Polyolefin resin has excellent physical, chemical, and electrical properties, so it can be made into molded products, pipes, sheets, films, fibers, etc. by extrusion molding, injection molding, blow molding, etc. It is processed and used in a wide range of fields.

However, when polyolefin resins such as polyethylene, polypropylene, and their copolymers are used alone, they are relatively easily affected by heat and light in the presence of oxygen during processing or use. It is known that due to oxidative deterioration, phenomena such as softening, embrittlement, and discoloration occur, resulting in a significant decrease in physical properties, making it impossible to withstand various uses.

In order to prevent such aging phenomena, improved techniques using various antioxidants or a combination of two or more antioxidants have been developed.

For example, 2,6-di-t-butyl-4-methylphenol, n-octadecyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, tetrakis[methylene-3-(3°5 -di-t-butyl-4-hydroxyphenyl)propionate comethane, 3.5-
Trimethyl-2,4,6-)lis(3,5,-di-t-
Antioxidants such as butyl-4-hydroxybenzyl)benzene and 1,1°3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane 11. There are improvement methods that use antioxidants or combinations of these antioxidants with dilaurylthiodipropionate, distearylthiodipropionate, or pentaerythritol-tetrakis (β-dodecylthiopropionate). Are known.

On the other hand, incorporating tris(3-methyl-5-t-butyl-4-hydroxybenzyl) isocyanurate into a polyolefin resin to prevent aging is the invention of the present invention described in Japanese Patent Publication No. 46-35041. Although it is known from the fact that it is included in the general formula, there is no specific example of the above compound in the specification of the invention, and it tends to be the case that the structurally symmetric tris-( Since the 3,5 di-t-alkyl-4-hydroxybenzyl) isocyanurate derivative is described as a preferred compound, it is formally included in the above invention; This suggests that it is less effective than the other compound, so we could not have much hope for its effectiveness.

<Problems to be Solved by the Invention> However, it has been difficult to obtain a fully satisfactory result even with the improvement technique using a combination of the above-mentioned antioxidants, and it has been difficult to obtain a sufficiently satisfactory result by using the above-mentioned asymmetric compound alone. However, as described in the above specification, it was not possible to exhibit the excellent effects, and it was difficult to put it into practical use.

[Summary of the invention]

Summary> As a result of extensive research in view of the above issues, the present inventors have found that by blending a specific phenol compound and a specific sulfur compound into a polyolefin resin, the present inventors have succeeded in improving the effectiveness of conventional antioxidants. The present inventors have discovered that a polyolefin resin composition can be obtained that exhibits a surprising synergistic effect with extremely excellent thermal and oxidative stability that would be difficult to predict from a combination technique, and has completed the present invention.

That is, the polyolefin resin composition of the present invention comprises 100 parts by weight of a polyolefin resin, 0.01 to 3 parts by weight of a phenolic compound represented by the following formula (I), and 0101 to 0101 of a sulfur compound having two or more sulfur atoms. 3 parts by weight.

(I) Effect> The polyolefin resin composition containing the specific phenolic compound of the present invention and a sulfur compound having two or more sulfur atoms is excellent in aging at high temperatures, which is susceptible to oxidative deterioration. Therefore, it is useful as a material for automobile exterior materials, hollow containers, sheet molded products, etc., which are sometimes heated to high temperatures.

[Detailed description of the invention]

[I] Constituent Component (I) Polyolefin Resin Component The polyolefin resin used in the polyolefin resin composition of the present invention includes poly-α-olefins such as low-density polyethylene, medium-density polyethylene, linear low-density polyethine, polypropylene, and polybutene-1; Polyα-olefin copolymers such as ethylene/propylene random or block copolymers, ethylene/butene 1 random copolymers, polyα-olefin copolymers such as maleic anhydride-modified polypropylene, and mixtures thereof, etc. Among these, it is particularly effective for propylene polymers.

(2) Phenol Compound The phenol compound used in the polyolefin resin composition of the present invention is represented by the following formula (I).

(I) (3) Sulfur-based compound component The sulfur-based compound used in the polyolefin resin composition of the present invention is a sulfur-based compound having two or more, preferably three or more, sulfur atoms in the molecule. Such sulfur compounds have the following chemical formulas:

1 (R-S-CH2CH2C-) aZ (II) (, III) (However, a in the formula represents an integer of 2 to 12, preferably 3 to 6, and 1 R is 2o+1l-CH2CH2COCoH2 in -Cn
n+1 (n is an integer of 8 to 201, preferably 10 to 18), Z is CH2O- -O-CH2-C CmH2II+1 (m is an integer of 1 to 5), H2O- H2O- -0-CH2- C-CH2-OH H2O- H2O- -0-CH2-C-CH2-0- CH2O- CH2O- CH20 Next, specific examples of these compounds are shown below.

1: (H25C12-8-C No.

5: (H2Se, 2-3-C :H2CH2C0CH2-)4C 1 H2-8-CH2CH2COCH2-)4C1 H-8-CH2CH2COCH2-)3C-C2H51 :H2CH2C0CH2-) C-CHOH 32 No.

11: H25C120CCH2CH2-3-CH2C1 H25C120CCH2CH2-8-CH25C120
CCH2CH2-8-Cmonth1 [ etc. can be mentioned.

(4> Other compounding agent components The polyolefin resin composition of the present invention includes the above (I) to (
In addition to the essential components 3), additives such as ultraviolet absorbers, light stabilizers, phosphorus stabilizers, antioxidants, metal deactivators, metal soaps, nucleating agents, lubricants, antistatic agents, and flame retardants. , pigments, pigment dispersants, fillers, etc., may be included within the range that does not significantly impair the effects of the present invention.

In particular, ultraviolet absorbers, hindered amine light stabilizers, etc., such as 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2(2'-hydroxy-5'-methylphenyl)benzotriazole, 2(2'-hydroxy-
3'-t-butyl-5'-methylphenyl)-5-chloro-benzotriazole, 2(2'-hydroxy-
3'5' -di-t-butylphenyl)-5-chloro-benzotriazole, 2(2' -hydroxy-3
'5'-di-t-amylphenyl)benzotriazole, [2,2'-thiobis(4-t-octylphenolate)]butylamine Ni salt, 2.2,6,6-
Tetramethyl-4-piperidylbenzoate, bis(2
, 2,6,6-tetramethyl-4-piperidyl) sebacate, 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butyl-malonate bis(I,2,
2,6,6-bentamethyl-4-piperidyl), 1-
[2-+3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy)ethyl]-4-[
'4- (3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy] -2,2,6,6-
Tetramethyl biveridine, dimethyl succinate 1- (
2-hydroxyethyl)-4-hydroxy-2,2,6
, 6-tetramethylbiperidine polycondensate, tris(I,
2,2,6,6-bentamethyl-4-piperidyl)phosphite, poly[[6(I,1,3,3,-tetramethylbutylimino)-1,3,5-triazine-2,4-
diyl]((2,2,6,6-tetramethyl-4-piperidyl)imino)hexamethylene((2,2,6-tetramethyl-4-piperidyl)imino)], poly[[6
-morpholino-1,3,5-triazine-2,4-diyl)((2,2,6,6-tedramethyl-4-piperidyl)imino]hexamethylene C(2,2,6,6-tetramethyl-4 -piperidyl)imino]], tetrakis(
2,2,6゜6-tetramethyl-4-piperidyl)-1
Its light resistance can be improved by adding 23,4-butanetetracarboxylate or the like.

Further, by adding a phosphorus antioxidant to the polyolefin resin composition of the present invention, its hue, heat aging resistance, and weather resistance can be improved. Examples of these phosphorus antioxidants include distearylpentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, and tris(2-t-butyl-
4-methylphenyl) phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, teratokis(2,4-di-t-butylphenyl)-4,4'-biphenylene diphosphonite , tetratridecyl-4,4'-butylidenebis-(3-methyl-6-t-butylphenol)-diphosphite,
Bis-(2,6-di-t-butyl-4-methylphenyl)
It is possible to avoid drugs such as pentaerythritol diphosphite.

(n) Formulation (I) ffi ratio The total addition of phenolic compounds and sulfur compounds in the polyolefin resin composition of the present invention is such that the amount of phenolic compounds added is 0 to 100 parts by weight of the polyolefin resin.
．． 01 to 3 parts by weight, preferably 0.05 to 1 part by weight,
0.01 to 3 parts by weight of a sulfur compound, preferably 0.0
It is 5 to 1 part by weight. In addition, the weight ratio of the sulfur compound to the phenol compound in combination is 0.5 to 20. In particular, it is preferably within the range of 0.5 to 6.

(2) Compounding The polyolefin resin composition of the present invention is prepared by mixing the above-mentioned compounds using a mixer such as a roll, Henschel mixer, super mixer, ■ blender, tumbler mixer, ribbon blender, Banbury mixer, kneader blender, or extruder. After mixing for a predetermined period of time, it is preferable to form the mixture into pellets using an ordinary extruder.

In addition, the blending ratio of the composition components in the above mixed crosstalk is as follows:
In addition to blending the desired amounts of each component, a polyolefin resin component is blended in a larger amount than the target composition (consisting of a phenolic compound component and a sulfur compound) to form a highly concentrated blend. This may be used as a so-called masterbatch, which is diluted and mixed with a polyolefin resin immediately before molding.

(m) Application In the above, the polyolefin resin composition has been specifically explained in relation to the present invention, but instead of the above polyolefin resin, the following synthetic polymers can also be used, and these synthetic polymers include: Polyvinyl chloride, methacrylic resin, polystyrene, high-impact polystyrene, ABS resin, AES resin and other nostyrene resins, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamide, polycarbonate, polyacetal, polyethylene oxide, polyphenylene ether, polysulfone, polyurethane , unsaturated polyester resin, etc.

Furthermore, natural polymers such as cellulose, rubber, protein, cellulose acetate, and derivatives thereof, and natural organic compounds such as mineral oil, animal and vegetable oils, and wax can also be used.

[Experiment example]

The present invention will be explained in more detail with reference to Examples and Comparative Examples below.

Examples 1 to 10 and Comparative Examples 1 to 14 Polypropylene powder 1 with an intrinsic viscosity of 1.9 measured in tetralin at 135°C and 98% isotactic
Each additive shown in Table 1 was added to 0.00 parts by weight and thoroughly mixed with a mixer.

And cylinder temperature 260℃, L/D-20゜20m
The mixture was melt-kneaded and granulated using an m-diameter extruder. The pellets thus obtained were compression molded at 230° C. into a sheet with a thickness of 0.5 mm to obtain a test piece.

Heat aging resistance was determined by heating a test piece in a circulating air oven at 150°C and measuring the time required until the test piece became brittle due to oxidative deterioration.

Weather resistance was determined using an Atlas 65/XW-WR xenon weather meter, when the test piece was irradiated with light at a black panel temperature of 80°C and the test piece was bent at 180 degrees.
The time required for the test piece to become brittle and crack was measured.

The results were as shown in Table 1.

The abbreviations in Table 1 are as follows.

Compound (I) Phenolic compound Nos. 1 to 12 described in the text Sulfur-based compounds (sulfur-based antioxidant) described in the text DMT P Similistyl thiodipropionate (phenolic antioxidant) -1 Tris (3, 5-di-t-butyl-4-hydroxybenzyl) isocyanurate (trade name: Good Rlte 3114)-2 tris(3,5-dimethyl-4-hydroxybenzyl)
Isocyanurate-3 Tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethylcomethane (trade name: lrganox 1010)-4 3,9-[bis1,1-di- Methyl-2(β-(3-t
-butyl-4-hydroxy-5-methylphenyl)propionyloxy)ethyl]-2.4.8,1.0-tetraoxaspiro[5,5-oundecane (trade name; MA■AO-80)

Claims (1)

[Claims] 1. 100 parts by weight of polyolefin resin, the following formula (I)
0.01 to 3 parts by weight of a phenolic compound represented by and 0.01 to 3 parts by weight of a sulfur compound having 2 or more sulfur atoms
A polyolefin resin composition comprising parts by weight. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼