JPH0881679A - Use of sulfur dye in solid form as antioxidant for polymer substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a polymer substance against heat, light, and oxygen with effects superior to those of known antioxidants by using a solid sulfur dye as an antioxidant for the polymer substance.

SOLUTION: A solid sulfur dye (pref. in the form of an ultrafine powder having an average particle size of 1-10 μm) is used as an antioxidant for a polymer substance (prepf. a polyolefin) to be stabilized. Pref., the dye has 1-10 repeating units such as represented by the formula, C.I.Sulfur Brown 96 being a pref. example. Pref., the dye in the form of a masterbatch in the same polymer as or a compatible polymer with the polymer substance is blended into a melt contg: the polymer substance. Pref., the dye is used in an amt. of 0.005-5 wt.% of the polymer substance.

COPYRIGHT: (C)1996,JPO

Description

Detailed Description of the Invention

[0001]

The present invention relates to the use of sulfur dyes as antioxidants for polymeric substances, especially polyolefins.

[0002]

BACKGROUND OF THE INVENTION Many types of antioxidants are known. One of the more common phenolic antioxidants on the market is (for example) "I".
tetrakis [methylene-3 (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (hereinafter “TMBP”) commercially available as rganox “1010 ™”.

[0003]

Surprisingly, it has been found that the stable oxidized form of the sulfur dyes (rather than the leuco form) acts as a very good antioxidant. In fact, sulfur dyes can in some cases work better than TMBP.

The present invention provides the use of sulfur dyes, preferably in solid form, as antioxidants for polymeric materials.

[0005]

DETAILED DESCRIPTION OF THE INVENTION It is essential that the sulfur dyes used in the present invention are not in the reduced form, ie, not the leuco sulfur dye form, but rather the oxidized form.

Further in accordance with the present invention there is provided a masterbatch composition (hereinafter referred to as a masterbatch) comprising a polymeric material and a sulfur dye as an antioxidant.

The sulfur dye is 5 to 40% by weight, preferably 5
It is preferred to be present in the masterbatch at a concentration of .about.20% by weight, more preferably about 10% by weight.

The sulfur dye used is preferably an ultrafine powder having an average size of preferably 1 to 10 μm.

Sulfur dyes, also known as sulfur vat dyes, are well known in the art, for example VENKAT.
ARAMEN “The Chemistry of S
ynthetic Dyes ”, Volume II (Chapter XXXV and XXXVI) (1952) and Volume VII (1974), or“ Color
Defined in the Index as "sulfur dyes" and even "vat dyes", there is a further description of sulfur and synthetic methods involving the number of structures and / or sulfurization. Dyes containing aromatically linked oligosulfide bridges that can be reduced to thiol groups and, optionally, have a structure ranging from oligomers to polymers, which have essentially no solubilizing sulfo groups and no thiosulfonic acid groups. It doesn't hold.

The sulfur dye which can be preferably used is C.I. I. Sulfur Black 1 C.I. I. Sulfur Black 2 C.I. I. Sulfur Black 11 C.I. I. Sulfur Black 18 C.I. I. Sulfur Red 10 C.I. I. Sulfur Red 14 C.I. I. Sulfur Blue 3 C.I. I. Sulfur Blue 7 C.I. I. Sulfur Blue 11 C.I. I. Sulfur Blue 13 C.I. I. Sulfur Blue 15 C.I. I. Sulfur Blue 20 C.I. I. Vat dye blue 43 C.I. I. Sulfur Green 2 C.I. I. Sulfur Green 16 C.I. I. Sulfur Green 35 C.I. I. Sulfur Green 36 C.I. I. Sulfur Brown 1 C.I. I. Sulfur Brown 3 C.I. I. Sulfur Brown 10 C.I. I. Sulfur Brown 21 C.I. I. Sulfur Brown 26 C.I. I. Sulfur Brown 31 C.I. I. Sulfur Brown 37 C.I. I. Sulfur Brown 52 C.I. I. Sulfur Brown 95 C.I. I. Sulfur Brown 96 C.I. I. Sulfur Orange 1 C.I. I. Sulfur Yellow 9 C.I. I. It is a dye selected from Sulfur Yellow 22.

Further preferred sulfur dyes are dyes containing 1 to 10 units, said units being of the formula:

[0012]

Embedded image

## STR1 ## where both groups R ₁ and both groups R ₂ together with the carbon atoms attached to them form a phenyl or naphthyl group. .

The most preferred sulfur dyes are of formula 1 or formula 2:

[0015]

Embedded image

[0016]

[Chemical 3]

It is a dye containing 1 to 10 repeating units represented by:

Among the sulfur dyes that can be used in the present invention,
C. I. Sulfur Brown 96, C.I. I. Sulfur Black 1, C.I. I. Sulfur Black 11 and C.I.
I. Sulfur Green 16 is particularly preferred. Particularly preferred sulfur dyes for use in the present invention are C.I. I. It is Sulfur Brown 96.

The present invention further provides a method of stabilizing a polymeric material against the effects of heat, light and oxygen (eg, against weather conditions). The process consists of adding to the polymeric material a masterbatch containing a stabilizing amount of said sulfur dye or a stabilizing amount of sulfur dye.

Preferably, the stabilizing amount is 0.005-5%, based on the polymeric material to be stabilized.

Suitable polymeric materials are polyolefins,
Polyamides, polycarbonates, acrylonitrile-butadiene-styrene copolymers, polystyrenes, styrene-acrylonitrile copolymers, high-impact polystyrenes, polyesters, polyetherketones and polyethersulfones.

Preferred polymeric materials are polyolefins such as polyethylene (eg high density polyethylene, low density polyethylene, linear low density polyethylene or medium density polyethylene), polybutylene, poly-4-methylpentene and copolymers thereof.

Further preferred polymeric materials use polyolefins, and reaction catalysts known as Generation I to Generation V catalysts, which may or may not be (but preferably is not) treated in the catalyst removal step. Is a copolymer produced by

The "catalyst removal step" is a compound (eg, alcohol) capable of reacting the polyolefin with the catalyst residue to inactivate or solubilize the residue in order to positively remove the catalyst residue contained in the polymerized polyolefin. Or water) and then removing the inactivated or solubilized catalyst residue by physical means such as filtration, washing and centrifugation.

Thus, in the case of suspension polymerization, the catalyst dissolved in the dispersion medium can be removed in a separation step, but the step of separating the resulting polymer from the dispersion medium such as solvent or liquefied monomer is defined above. It is not included in the catalyst residue removal step. The step of adding small amounts of catalyst poisons (e.g. ethers, alcohols, ketones, esters and water) together with vapors or gases such as nitrogen to the resulting polymer suspension is also not included in the above catalyst residue removal step.

Generation I catalysts are titanium halide catalysts and organoaluminum compounds or organoaluminum halides.

The II-generation catalyst is a I-generation catalyst having an organomagnesium compound as a carrier or an organochrome compound supported on SiO ₂ as a main component.

The third generation catalyst is a Ziegler type complex catalyst supported on a halogen-containing magnesium compound.

A Generation IV catalyst is a Generation III catalyst containing a silane donor.

Generation V catalysts are bis-indenyl organotitanium compounds supported on alumoxane or bis-cyclopentadienyl-titanium halides activated by aluminum alkyl compounds.

Particularly useful for the production of highly stereoregular polyolefins, the next generation of very special catalysts currently under development also belong to the above-mentioned generation of supported catalyst systems according to the invention. Examples of such highly stereoregular polyolefins are syndiotactic polypropylene, isotactic stereoblock polymers, isotactic polypropylene containing steric defects distributed along the polymer chain (so-called anisotactic polypropylene) or stereoregular. It is a stereoblock polymer.

Due to the rapid progress made in the development of new generation supported catalyst systems (eg metallocene catalysts), the commercial significance of these polymers with highly advantageous new properties is steadily increasing. However, the residue of such a next-generation catalyst contains the metal of 3d, 4d, and 5d of the periodic table supported in the same manner as the catalyst of the conventional generation, and such a residue is not physically removed. If left in the polymer, even in its deactivated form, it can lead to adverse properties to the polymer.

These generations of catalysts are described in May 1990, 2
Adva held in Lucerne, Switzerland from 1st to 23rd
nces in the Stabilization
and Controlled Degradati
The paper "New by Rolf Mulhaupt" at the 12th Annual International Conference on on Polymers
Trends in Polyolefin Cat
alysts and Fluence on Po
Lymer Stability "pp. 181-196.

The contents of this article, in particular Table I on page 184, which describes the catalyst generation, is hereby incorporated by reference:

[0035]

[Table 1]

In the table, R is an organo group, HDPE is high density polyethylene, LLDPE is linear low density polyethylene, Cp is cyclopentadienyl, Et is ethyl and PP is polypropylene. Yes, MWD is the molecular weight distribution.

The masterbatch of the present invention may be added before the polymerization step, during the polymerization step, or after the polymerization step. And 90% by weight of the composition in solid or molten form or solution, preferably 90% by weight.
As a liquid concentrate comprising ~ 20% by weight of solvent, or
90 to 20% by weight (more preferably 60 to 30% by weight) which is identical or compatible with 0 to 80% by weight (more preferably 40 to 70% by weight) of the composition to be stabilized. Can be added as a solid masterbatch composition comprising

It is of particular importance to blend the masterbatch into the melt containing the polymeric material to be stabilized.

The oxidized sulfur dye may be incorporated into the polymeric material to be stabilized by known methods. Such methods include dry blending sulfur dyes and fluffy polymers. For example, a sulfur dye may be added to the melt in a melt blender or during molding of molded articles (eg foils, films, tubes, containers, bottles, fibers and foams), injection molding, blow molding, spin molding, spinning or wire coating. Blending is especially important. For all types of polypropylene and polyethylene products,
It is particularly preferred to use the sulfur dyes of the invention alone or as a masterbatch.

Other antioxidants may be added to the polymeric material before, during or after the addition of the composition of the present invention (but prior to the initiation of polymerization).

Examples of other suitable antioxidants include benzofuran-2-one, indoline-2-one, sulfur and phosphorus containing compounds, and mixtures thereof.

Preferred sulfur-containing antioxidant co-stabilizers that can be used include ditridecyl-3,3-thiodipropionate, distearyl-3,3-thiodipropionate, dilauryl-3,3-thiodipropionate. , Methane tetrakis (methylene-3-hexyl thiopropionate), methane tetrakis (methylene-3-dodecyl thiopropionate) and dioctadecyl disulfide.

Preferred phosphorus-containing costabilizers which can be used are trinonylphenyl phosphite, 4,9-distearyl-3,5,8,10-tetraoxadiphosphaspiroundecane, tris- (2,4- Di-t-butylphenyl) phosphite, trilaurylphosphite,
Bis (2,6-di-t-butyl-4-methylphenyl)
Pentaerythrityl diphosphite, bis (2,4-di-t-butylphenyl) pentaerythrityl diphosphite, distearyl pentaerythrityl diphosphite and tetrakis- (2,4-di-t-butylphenyl)
Includes -4,4'-biphenylene diphosphonite.

Other additives that can be added to the polymer composition of the present invention include aminoaryl compounds, ultraviolet stabilizers, antistatic agents, flameproofing agents, softening agents, plasticizers, lubricants, and guard agents. ), Complexing agents, nucleating agents, metal deactivators, biocides, impact modifiers, fillers, pigments and bactericides.

Preferred aminoaryl compounds include N,
N'-dinaphthyl-p-phenylenediamine and N,
N'-hexamethylene-bis-3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionamide.

Preferred UV stabilizers include UV absorbers such as 2- (2'-hydroxyphenyl) benzotriazole, 2-hydroxybenzophenone, 2-hydroxyphenyl-1,3,5-triazine 1,3-bis-. (2′-hydroxybenzoyl) benzene salicylate, cinnamate and oxalic acid diamide), UV quenchers (eg benzoates and substituted benzoates), and hindered amine light stabilizers (eg N-unsubstituted, N-alkyl or N-acyl-substituted 2). , 2,6,6-Tetraalkylpiperidine compound).

Such an additive is known as "Kunstoff".
e Additive ”Gachter / Mulle
r, Vol. 3, 1990, pp. 42-50. The contents of which are incorporated herein by reference. See the last two lines on page 4 for this.

[0048]

The present invention will be described in the following examples. All parts and percentages are by weight and all temperatures are in ° C.

90 parts of low density polyethylene in powder form, commercially available as Escorene (Exxon), was mixed with 10 parts of ultrafine C.I. I. Mix with Sulfur Brown 96 (average size: 1-5μ) for 4-5 minutes.

This mixture was then predispersed in a TRAF Brabender at 140 rpm for 3 seconds. The obtained masterbatch was added to polypropylene commercially available as Moplen manufactured by Himont at a concentration of 0.05%. It is then extruded 5 times, M after each pass
The FI (melt flow index) was measured.

Another commercially available polyethylene that can be used in place of Escorene in this example is PE from Repsal.
022 GRADO 70, DSM Stamyla
Riblen manufactured by nLD and Enichem.

Another commercially available polypropylene that can be used in place of Moplen in this example is Propa from ICI.
These are tene, Solvay's Eltex, and Shell's SM.

0.05% of C.I. I. Sulfur Black 1, C.I. I. Sulfur Black 11 and C.I. I. The example was repeated using Sulfur Green 16. The results are as follows:

[0054]

[Table 2]

Claims (4)

[Claims] 1. The use of sulfur dyes in solid form as antioxidants for polymeric substances. 2. A C.I. I. Use according to claim 1 of Sulfur Brown 96. 3. A masterbatch composition comprising a polymeric material and a sulfur dye as an antioxidant. 4. The sulfur dye is C.I. I. The masterbatch according to claim 3, which is Sulfur Brown 96.