DE2828363A1 - LIGHT-STABLE POLYOLEFINE MATERIAL - Google Patents

Description

PFENNING MAAS

MEtNIG - LEMKE - Mockery

6CHL.E15SHE1MERSTR. 299 8000 MUNICH 40

26 798

American Cyanamid Company, Wayne, New Jersey, V.St.A. Light stable polyolefin compound

The invention relates to a light-stable polyolefin composition. It deals in particular with a polyolefin composition which stabilizes against degradation by the action of light which is characterized in that it is a combination of a stabilizer

(a) 2-Hydroxy-4-alkoxybenzophenone or a 2- (2 ^! -hydroxy-5'-alkylphenyl) benzotriazole in which the alkoxy and alkyl substituents contain up to 12 carbon atoms, and

(b) a compound of the formula (I)

(D

wherein

represents alkyl or alkenyl each having 1 to 20 carbon atoms,

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R2 denotes alkyl with 1 to 8 carbon atoms and

R _{3 is} an alkyl branched on the alpha carbon atom and having 3 to 8 carbon atoms,

contains.

The substituent R ₁ is preferably alkyl having 6 to 20 carbon atoms, and the substituents are preferably each t-butyl.

20 carbon atoms, and the substituents R _? as well as R.,

Sunlight and other sources of ultraviolet light are known to cause polymer degradation to occur by the plastic objects made from them becoming brittle or yellowing. This degradation can go through Incorporation of light-stabilizing additives in such counterpart. to inhibit stands.

To extend the service life of products made from polyolefins Various additives are already used in objects, either alone or in combinations. None however, these additives give completely satisfactory results, and new and better compounds are therefore being sought or connection combinations sought.

Surprisingly, it has now been found that polyolefin compositions to stabilize against degradation by the action of light, if one of these stabilizing amounts from (a) a 2-hydroxy-4-alkoxybenzophenone or a 2- (2'-hydroxy-5'-alkylphenyl) benzotriazole, wherein the alkoxy and alkyl substituents contain up to 12 carbon atoms, and (b) one Compound of the formula (I) mentioned at the outset is added.

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Effective stabilization generally occurs when the corresponding polyolefin compositions about 0.1 to contain about 4.0% of each light stabilizing compound based on the weight of the polyolefin.

The masses to be stabilized are preferably polypropylene masses, which are about 0.2 to 2.0% of each contain light stabilizing compound, based on the weight of the polypropylene. Above all, it is to compositions of polypropylene containing about 0.25 percent by weight of 2-hydroxy-4-n-octyloxybenzophenone or 2- (2'-hydroxy-5'-toctylphenyl) benzotriazole and 0.25 percent by weight n-hexadecyl 3f5-di-t-butyl-4-hydroxybenzoate included, based on the weight of the polypropylene.

The masses according to the invention are significantly more stable than similar masses to the destructive influence of light of polyolefin and an equal total amount of a single known light stabilizing compound with the sole Use.

The compositions according to the invention result in light-stable polyolefins, which are suitable for the production of films, foils and fibers, in particular films and foils.

The light-stabilizing compounds can be converted into such Plastic materials according to any known one suitable for this purpose. Process can be incorporated by either dry mixing the additive with the polyolefin in powder or granular form, the whole is then ground, mixed in a Banbury mill, shaped, poured, extruded or swelled leaves, or by the polyolefin, for example as a film, sheet or fiber, in a solution of the additive in a suitable Solvent (as in a dyeing process) dips.

80983S / ÖS56

The amounts of light-stabilizing substances required for effective stabilization of the polyolefin against degradation Compounds are dependent on the type of polyolefin and the degree of exposure to ultraviolet light to which the respective Item is later exposed.

The esters of the formula (I) mentioned at the outset can be prepared by adding a corresponding 3,5-dialkyl-4-hydroxybenzoic acid with a suitable alcohol in the presence of a catalyst such as sulfuric acid. You let by reacting the corresponding alcohol with a suitable 3,5-dialkyl-4-hydroxybenzoyl chloride produce.

The preparation of a number of compounds of the formula (I) can be found in the literature. In U.S. Patent No. 3,681,431, Examples 1 to 3 describe the preparation of n-octadecyl, n-hexyl, and n-dodecyl esters of _{3/5-di-t-butyl-4-hydroxybenzoic} acid.

Examples of suitable compounds falling under formula (I) are the following:

n-octadecyl-3,5-di-t-butyl-4-: hydroxybenzoate, n-hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate, n-octadecyl-3,5-diisopropyl-4-hydroxybenzoate, Isobutyl 3,5-di-t-octyl-4-hydroxybenzoate, Methyl 3-methyl-5-isopropyl-4-hydroxybenzoate, Cyclohexyl 3,5-di-t-amyl-4-hydroxybenzoate, Allyl 3,5-di-t-butyl-4-hydroxybenzoate,

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2-butenyl-3,5-diisopropyl-4-hydroxybenzoate or n-Octadecyl-S-n-octyl-S-t -butyl ^ -hydroxybenzoate.

Examples of suitable light stabilizers from the class of the 2-hydroxy-4-alkoxybenzophenones are the following:

2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-n-butoxybenzophenone, 2,2'-dihydroxy-4-n-octyloxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-n-decyloxybenzopheno.n, 2,2'-dihydroxy-4,4'-di-n- (octyloxy) benzophenone, 2,2'-dihydroxy-4-i-butoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone or 2-hydroxy-4-isooctyloxybenzophenone.

Examples of suitable light stabilizers from the class of the 2- (2'-hydroxy-5 ¹ -alkylphenyl) benzotrxazoles are the following;

2- (2'-Hydroxy-5'-t-octylphenyl) benzotriazole, 2- (2 ¹ -hydroxy-5'-methy! Phenyl) benzotriazole,

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2- ^(2-hydroxy-r 5'-t-butyl-phenyl) benzotriazole, 2- (2'-hydroxy-5'-amylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dimethylphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-buty! phenyl) -5-chlorobenzotriazole, 2- (2 ¹ -hydroxy-5 ¹ -t-octylphenyl) -5-methoxybenzotriazole, 2- (2'- Hydroxy-5'-t-octylphenyl) -5-ynethylbenzotriazole, 2- (2'-hydroxy-5'-dodecylphenyl) benzotriazole,

2- (2'-Hydroxy-3'-t-butyl-5'-methy! Phenyl) -5-chlorobenzotriazole or

2- (2'-Hydroxy-3 ', 5 * -di-t-butylphenyl) -5-chlorobenzotriazole.

The combination according to the invention of the light stabilizing Compounds is useful for protecting organic polymeric materials that normally degrade by ultraviolet light especially for the protection of polyolefins. Such polyolefins include homopolymers, such as high-density polyethylene, High pressure polyethylene, polypropylene, polystyrene, Polybutadiene, polybutylene or polyisoprene, and copolymers such as ethylene-propylene copolymer, ethylene-butylene copolymer, Ethylene-vinyl acetate copolymer, styrene-butadiene copolymer or Acrylonitrile-styrene-butadiene copolymer.

The above-mentioned combination of light stabilizing compounds can also be used in combination with other additives, such as antioxidants, fillers, Pigments, dyes, or antistatic agents.

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The invention is further illustrated by the following examples. All parts and percentages contained therein are based on weight, unless otherwise stated.

Examples 1-6 General Procedure

Unstable polypropylene (100 parts) is dry blended with 2,6-di-t-butyl-4-methylphenol (0.05 part) octadecyl-3,5-di-t-butyl-4-hydroxyhydrocinnamate (0.05 part) , Calcium stearate (0.10 part) and the stabilizer additive to be examined (0.50 part) or the combination of two stabilizer additives to be examined (0.25 part each). The mixed mass is then extruded ^{at a maximum temperature of 227 ° C.} and pelletized. 1 to Einfäden: thereafter extruding the resulting pellets under a maximum temperature of 252 ⁰ C and a draw ratio of. 7 The threads obtained are then exposed to a xenon arc in a weathering device (Weather-Ometer) for various periods of time, whereupon the breaking strength of the threads is examined. The results obtained in this way are converted into percentages compared to the original strength of the threads.

According to the method described above using appropriate light-stabilizing compounds or combinations Results obtained from light-stabilizing compounds are shown in Table I below. The examples 1 to 4 of this table show those using in each case 0.5 part of the specified light-stabilizing compound results obtained alone. Also in this

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4 »

Table also shows the test results of combinations of 2-hydroxy-4-alkoxybenzophenone and 2- (2'-hydroxy-5'-alkoxyphenyl) benzotrxazoles with 3,5-di-alkyl-4-hydroxybenzoate (Examples 5 to 6 - prior art) or with alkyl-3,5-di-alkyl-4-hydroxybenzoate (Examples 7 to 8 - invention) present-

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Table I.

thread

Example addition

1 * 2-hydroxy-4-n-octyloxybenzophenone (0.50 parts)

O CO OO 00 OD

2 * 2- (2'-hydroxy-5'-t-octylphenyl) benzo triazole (0.50 parts)

3 * 2,4-di-t-butylphenyl ~ 3,5-di-t-butyl-4-hydroxybenzoate (0.50 parts)

4 * n-hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate (0.50 parts)

5 * 0.25 parts each of the additives of Examples 1 and

6 * 0.25 parts each of the additives of Examples 2 and

7 each 0.25 part of the additives of Examples 1 and

8 each 0.25 part of the additives of Examples 2 and

* = Comparative examples

denier

133

134

140

145

147

169

158

155

Initial toughness

6.8 6.9 6.7 7.0 6.5 6.4 7.0 6.2

Percent of the original strength

1200 1600 2000 2400 2600 hours hours hours hours hours hours

88

88

79

88

87

94 '

95

73

73

81

79

87

82

87

96

67

62

61

70

73

72

93

89

57

54

63

62

75

66

85

93

NJ CO GO CO

The above test results show that the invention Bar / lizer combinations result in a significant improvement in the light stabilization of polypropylene.

The process described in Example 4 is repeated, but instead of the additive used there 0.25 part of the following compounds used: n-octadecyl-3,5-diisopropyl-4-hydroxybenzoate, Isobutyl-3,5-di-t-octyl-4-hydroxybenzoate, methyl-B-methyl-S-isopropyl ^ -hydroxybenzoate, Cyclohexyl 3,5-di-t-amyl-4-hydroxybenzoate, allyl-3,5-di-t-butyl-4-hydroxybenzoate, n-octadecyl-3,5-di-t-butyl-4-hydroxybenzoate or n-dodecyl-3,5-di-t-butyl-4-hydroxybenzoate. Similar results are obtained.

The process described in Example 7 is repeated, using instead of the 2-hydroxy-4-n-octyloxybenzophenone used there here, however, 0.1 to 4.0 parts of the following compounds are used: 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-n-butoxybenzophenone, 2,2 "-dihydroxy-4-n-octyloxybenzophenone, 2,2'-dihydroxy-4 , 4'-dimethoxybenzophenone, 2,2 ', 4,4'-n-octyloxybenzophenone, 2,2'-dihydroxy-4-i-butoxybenzophenone or 2,2'-dihydroxy-4-methoxybenzophenone. One arrives at similar ones Results.

The process described in Example 8 is repeated, using instead of the 2- (2'-hydroxy-5'-tocty! Phenyl) benzotrxazole used there here, however, 0.1 to 4.0 parts of the following compounds are used: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-Hydroxy-5'-t-buty! Phenyl) benzotriazole, 2- (2-hydroxy-5'-amylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dimethylphenyl) benzotriazole, 2- (2'-Hydroxy-5'-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'-Hydroxy-5'-t-octylphenyl) -5-methoxybenzotriazole, 2- (2'-Hydroxy-5'-toctylphenyl) -5-methylbenzotriazole, 2- (2'-Hydroxy-5'-n-dodecylphenyl) benzotriazole, 2- (2'-Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole or 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole. This again gives similar results.

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Example9

The method described in Examples 7 to 8 is carried out using 0.125 parts each of the light stabilizers according to Examples 1 and 2 and 0.25 parts of the ester according to Example 4, each to 100 parts of polypropylene, repeated, giving similar results.

Examples 10-11

The procedure described in Examples 7 to 8 is followed repeated, but using a high-impact ethylene-butylene copolymer instead of polypropylene. Again, similar results are obtained.

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Claims (8)

Claims 1. \ Light-stable polyolefin compound, thereby indicates that they are a combination of a stabilizer (a) 2-hydroxy-4-alkoxybenzophenone or a 2- (2'-hydroxy-5'-alkylphenyl) benzotrxazole, wherein the alkoxy and alkyl • contain substituents up to 12 carbon atoms, and (b) a compound of the formula (I) C-OR, wherein represents alkyl or alkenyl each having 1 to 20 carbon atoms, R. Denotes alkyl with T to 8 carbon atoms and an alkyl branched on the alpha carbon atom with 3 to 8 carbon atoms, contains. 2. Mass according to claim 1, characterized that it contains about 0.1 to 4.0% of each light stabilizing compound, based on · the weight of the polyolefin. " ORIGINAL INSPECTED 3. Composition according to claim 2, characterized in that it is about 0.2 to 2.0% of each Contains light stabilizing compound and the polyolefin to be stabilized is polypropylene. 4. Composition according to claim 1, characterized in that it contains a compound of the formula (I) in which R "and R _{3 are} each t-butyl. 5. Composition according to claim 1, characterized in that it contains a compound of the formula (I) in which R _{1 is} alkyl having 6 to 20 carbon atoms. 6. Composition according to claim 1, characterized draws that it contains a copolymer of propylene and ethylene as olefin. 7. Composition according to claim 1, characterized draws that they are made of polypropylene and each 0.25 percent by weight of 2-hydroxy-4-n-octyloxybenzophenone and n-hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate. 8. Composition according to claim 1, characterized in that it is made of polypropylene and 0.25 percent by weight of 2- (2 ¹ -hydroxy-5'-t-octylphenyl) benzotriazole and n-hexadecyl-3,5-di-t- butyl 4-hydroxybenzoate. 809836/0656