US 4,963,605 AGrant
Stabilized Polyolefin Composition
Issue Date:1990-10-16
•7 Claims
Abstract
The invention relates to a stabilized polyolefin composition, which composition is stabilized against deterioration caused by contact with heavy metals and improved in coloration properties. This is achieved by blending a polyolefin with: (A) a phenolic compound represented by the formula (I), ##STR1## wherein R.sub.1 represents a C.sub.1 -C.sub.3 alkyl group, (B) a metal deactivator having one or more ##STR2## groups in the side chain, and (C) a sulfur-containing compound represented by the formula (II-1), (II-2), (II-3) or (II-4): ##STR3## wherein R.sub.2 represents a C.sub.4 -C.sub.20 alkyl group, ##STR4## wherein R.sub.3 represents a C.sub.4 -C.sub.20 alkyl group, ##STR5## wherein R.sub.4 represents a C.sub.3 -C.sub.18 alkyl group, and R.sub.5 and R.sub.6 independently represent a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group, ##STR6## wherein R.sub.7 represents a C.sub.3 -C.sub.18 alkyl group.
Metadata
Assignee
- Sumitomo Chemical Company, Limited
Inventors
- Yoshiharu Fukui
- Kazuhisa Kuroda
- Tamaki Ishii
- Manji Sasaki
Application Information
Application Number:US 3245381
Filing Date:1989-03-16
Priority Date:1985-11-08
Art Unit:153
Classifications
IPC:
C08K 515C08K 534
Field of Search:
524108;219;289;423;424;430;436;442
Patent Drawings
This patent does not have any drawings.
Description
EXAMPLES 1 to 6
One hundred parts by weight of polypropylene(homopolymer) powders (intrinsic viscosity [.xi.],2.20), 0.05 part by weight of calcium stearate, the phenolic compound, metal deactivator and sulfur-containing compound were mixed. The mixture was mixed on a Henschel mixer and extruded into pellets at a temperature of 230.degree. C. on a 65 mm .phi. extruder in a nitrogen gas atmosphere. The pellets thus obtained were measured for melt index (MI) according to JIS K 7210.
These pellets were pre-heated for 10 minutes at a temperature of 230.degree. C. and formed into a press sheet of 1 mm in thickness. The press sheet obtained was brought into contact with a copper plate and placed in a Geer oven kept at a temperature of 150.degree. C. to measure the thermal stability.
Separately, the yellowness index (YI) of this press sheet was measured according to ASTM D 1925. The results are shown in Table 4.
Comparative examples 1 to 3
Test was carried out in the same manner as in Example 1 under conditions shown in Table 4 using the conventional pentaerythrito tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate](A-3) as the phenolic compound. The results are shown in Table 4.
Examples 7 to 10
Procedure was carried out in the same manner as in Example 1 except that a propylene/ethylene block copolymer (ethylene content, 7.3 wt. %; [.xi.]=2.45) was used as the polyolefin, and that 100 parts by weight of this block copolymer, 0.05 part by weight of calcium stearate the phenolic compound, metal deactivator, sulfur-containing compound and phosphite type compound, bis(2,4-di-tert-butylphenyl) pentaerythitol diphosphite, were blended together. The results are shown in Table 4.
Abbreviations in Table 4 represent the following compounds. Phenolic compound: ##STR24## A-3 Pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] ##STR25##
Sulfur-containing compound:
C-1 Dimyristyl thiodipropionate ##STR26##
Phosphite type compound:
D-1 Bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite
Examples 11 to 15
One hundred parts by weight of a resin composition comprising propylene/ethylene block copolymer powders (intrinsic viscosity [.xi.], 2.45; ethylene content, 7.3 wt. %) and talc (Micron White 5000S; a product of Hayashi Kasei K.K.) which was an inorganic filler was mixed with 0.05 part by weight of calcium stearate, the phenolic compound, metal deactivators sulfur-containing compound and 0.05 part by weight of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite. The mixture obtained was mixed on a Henschel mixer, kneaded and pelletized on a 65 mm.phi. extruder. The pellets obtained were preheated at a temperature of 230.degree. C. for 10 minutes and formed into a press sheet of 1 mm in thickness. The sheet obtained was brought into contact with a copper plate and placed in a Geer oven kept at a temperature of 150.degree. C. to measure the thermal stability.
The melt index (MI) of the pellets was measured according to JIS K 7210. the yellowness index (YI) of the press sheet was measured according to ASTM D 1925. The results obtained and the proportions of the materials are shown together in Table 5.
Comparative examples 4 and 5
Test was carried out in the same manner as in Example 11 under conditions shown in Table 5 using pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate](A-3) as the phenolic compound. The results are shown in Table 5.
Abbreviations A-1, A-2, A-3, B-1, B-2, C-1 and C-2 in Table 5 are the same as described above. Abbreviations, F-1, F-2 and F-3, of inorganic filler represent the following substances:
F-1 talc
F-2 calcium carbonate
F-3 calcium silicate.
Examples 16 to 18
Test was carried out in the same manner as in Example 11 under conditions shown in Table 5 using varying kinds of inorganic filler. The results are shown in Table 5 together with the results of other examples.
Comparative example 6
Test was-carried out-in the same manner as in Example 16 under a condition shown in Table 5 using A-3 as the phenolic compound The result is shown in Table 5.
According to the present invention, there is provided a composition stabilized against heavy metals which comprises blending a polyolefin such as polypropylene containing or not containing an inorganic filler with the particular phenolic compound, metal deactivator and sulfur-containing compound. This composition exhibits a greatly improved thermal stability as compared with the conventional compositions particularly when brought into contact with copper plates at high temperatures. This composition has also an improved coloration property.
Claims
What is claimed is:
1. A polyolefin composition which is comprised of a blend of 100 parts by weight of a resin composition comprising 100 to 35 weight percent of a polyolefin and 0 to 65 weight percent of an inorganic filler, and (a) 0.01 to 1 part by weight of a phenolic compound represented by the formula (I): ##STR27## wherein R.sub.1 represents a C.sub.1 -C.sub.3 alkyl group, (b) 0.01 to 10 parts by weight of metal deactivator represented by the formula (III-5); ##STR28## (c) 0.01 to 1 part by weight of a sulfur-containing compound represented by the formula (II-1) or (II-2): ##STR29## wherein R.sub.2 represents a C.sub.4 -C.sub.20 alkyl group, ##STR30## wherein R.sub.3 represents a C.sub.4 -C.sub.20 alkyl group.
2. A polyolefin composition as claimed in claim 1, wherein the resin composition comprises 95 to 60 weight percent of a polyolefin and 5 to 40 weight percent of an inorganic filler.
3. A polyolefin composition as claimed in claim 1, wherein in the phenolic compound represented by the formula (I), R.sub.1 is a methyl, ethyl or propyl group.
4. A polyolefin composition as claimed in claim 1, wherein the sulfur-containing compound is one represented by the formula (II-2), and the substituent R.sub.3 is a C.sub.6 -C.sub.18 alkyl group.
5. A polyolefin composition as claimed in claim 1, wherein the inorganic filler is at least one member selected from the group consisting of metal oxides, metal hydroxides, metal carbonates, metal sulfates, metal silicates, silicate minerals, carbides and ceramics.
6. A polyolefin composition as claimed in claim 1, wherein the inorganic filler has an average particle diameter not more than 20.mu., preferably in the range of 0.05 to 5.mu..
7. A polyolefin composition as claimed in claim 1, wherein the sulfur-containing compound is one represented by the formula (II-1), and the substituent R.sub.2 is a C.sub.12 -C.sub.18 alkyl group.