JPH06184365A - Stabilized polyolefinic resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition by mixing a polyolefinic resin with a hindered phenolic compound and a specified phosphorus compound and an N-substituted hindered piperidine compound. CONSTITUTION:This resin composition is prepared by mixing 100 pts.wt. polyolefinic resin with 0.01-1 pt.wt. hindered phenolic compound (A) of formula I (wherein R is H or 1-3 C alkyl), 0.01-1 pt. wt. specified phosphorus compound (B) selected from among bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl) phosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, etc., and 0.01-1 pt. wt. N-substituted hindered piperidine compound having at least one group of the formula II (wherein X is 1-4 C alkyl or 1-8 C alkoxyl) in the molecule.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a stabilized polyolefin resin composition. More specifically, a polyolefin that is not only stable against thermal oxidative deterioration and photodegradation during use, but also has excellent stability against discoloration due to combustion gas or nitrogen oxide gas (hereinafter abbreviated as NOx gas). The present invention relates to a resin composition.

[0002]

2. Description of the Related Art Polyolefin resins such as polypropylene and polyethylene have excellent physical, chemical and electrical properties and are therefore often used as materials for fibers, films, sheets and other molded articles. There is.
However, when these polyolefin resins are used, heat,
It has a problem that it is deteriorated by the action of oxygen or light and mechanical properties are deteriorated.

In order to suppress such deterioration, various stabilizers such as phenolic antioxidants, phosphorus antioxidants and hindered piperidine light stabilizers have been conventionally used.

As the phenolic antioxidant, for example, the following ones are used.

2,6-Di-t-butyl-4-methylphenol, 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 1,
3,5-tris (4-t-butyl-3-hydroxy-
2,6-Dimethylbenzyl) isocyanurate, tetrakis [(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane.

As the phosphorus-based antioxidant, for example, the following ones are used.

Distearyl pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,2 4-di-t-butylphenyl)
4,4'-biphenylene diphosphonate.

As the hindered piperidine-based light stabilizer, for example, the following ones are used.

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}], poly [(6-morpholino-1,3,5-triazine-2,4-
Diyl) {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-
Tetramethyl-4-piperidyl) imino}], a polycondensation product of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine.

On the other hand, the polyolefin resin is, for example,
In the drying process when molding into fibers, films, etc.
Often exposed to combustion gases such as city gas and kerosene,
Further, even in the usage environment after molding, there is a case where it is exposed to combustion gas generated from an automobile or an oil stove. The polyolefin-based resin containing various stabilizers as described above has a problem that it is easily discolored when exposed to this kind of combustion gas.

In order to improve such a problem, for example, Japanese Patent Application Laid-Open No. 4-7342 proposes a method of blending a specific hindered phenolic compound with a specific oligomeric hindered pipedrine compound. .

[0012]

However, the polyolefin resin compositions proposed hitherto are not only stable to heat, oxygen and light, but also to combustion gas and NOx.
Both of the stability against gas discoloration were not sufficiently satisfied. For example, the polyolefin composition described in Japanese Patent Laid-Open No. 4-7342 has a combustion gas and NO
Although it has excellent stability against discoloration due to x gas, its stability against light was not always sufficient.

Therefore, the present inventors have a sufficient stability against heat, oxygen and light, and at the same time, combusted gas and NO.
x As a result of earnest research to develop a polyolefin-based resin composition having excellent stability against discoloration due to gas, specific hindered phenol-based compounds, specific phosphorus-based compounds and specific hinder-based compounds are found in polyolefin-based resins. It has been found that by adding a dopiperidine compound, very excellent performance can be obtained, and the present invention has been completed.

[0014]

Means for Solving the Problems That is, according to the present invention, the following components (A), (B) and (C) are added in an amount of 0.01 per 100 parts by weight of a polyolefin resin.
The present invention provides a polyolefin-based resin composition containing 1 to 1 part by weight.

(A) The following formula (I)

[0016]

[Chemical 6]

(In the formula, R represents hydrogen or alkyl having 1 to 3 carbon atoms)

A hindered phenolic compound represented by:

(B) Bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite,
Tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite,
Bis (2,4,6-tri-t-butylphenyl) pentaerythritol diphosphite, tetrakis (2,4-di-t-butylphenyl) 4,4'-biphenylene diphosphonate, 2,2'- Ethylidene bis (4,6-di-t-butylphenyl) fluorophosphite, and 2,2'-methylenebis (4,6-
Di-t-butylphenyl) octyl phosphite;

(C) The following formula (II)

[0021]

[Chemical 7]

(In the formula, X represents alkyl having 1 to 4 carbons or alkoxy having 1 to 8 carbons)

An N-substituted hindered piperidine compound having at least one group represented by

The polyolefin resin used in the present invention is
Ethylene, propylene, 1-butene, isobutene, 1
-Hexene, 3-methyl-1-butene, 4-methyl-1
A homopolymer obtained from an α-olefin such as pentene or 1-decene, a random or block copolymer obtained from two or more α-olefins, an α-olefin and another copolymerizable unsaturated compound Copolymers and the like are included. These may be used alone or in a blend of two or more.

Examples of the homopolymer of α-olefin include polyethylene, polypropylene, poly-1-butene, polyisobutene, poly-3-methyl-1-butene, and poly-4.
-Methyl-1-pentene and the like are exemplified. Further, as the copolymer of α-olefins, ethylene / propylene copolymer, ethylene / 1-butene copolymer, propylene / 4-methyl-1-pentene copolymer, propylene /
Examples thereof include 1-butene copolymer, 1-decene / 4-methyl-1-pentene copolymer, ethylene / propylene / 1-butene copolymer and the like. Further, a polyunsaturated compound such as a conjugated diene or a non-conjugated diene or a monounsaturated compound such as acrylic acid, methacrylic acid or vinyl acetate as a copolymerization component is also included together with the α-olefin. These polymers may be acid-modified, for example, graft-modified with α, β-unsaturated fatty acids, alicyclic carboxylic acids, or derivatives thereof.
Among these polyolefin resins, polypropylene is particularly preferably used in the present invention.

In the present invention, the specific hindered phenol compound (A), the specific phosphorus compound (B) and the specific hindered piperidine compound (C) listed above are added to such a polyolefin resin. Compound.

The phenolic compound as the component (A) used in the present invention is represented by the above formula (I). R in the formula is hydrogen or alkyl having 1 to 3 carbon atoms, among which alkyl, that is, methyl, ethyl or propyl is preferable, and methyl is particularly preferable. As the phenolic compound (A), one in which R in the formula (I) is hydrogen or alkyl having 1 to 3 carbon atoms may be used alone, or two or more different Rs are combined. Can also be used.

The phosphorus-based compound as the component (B) is the above-mentioned 7
Selected from types. These phosphorus compounds may be used alone or in combination of two or more.

The piperidine compound as the component (C) is a group represented by the above formula (II), that is, N-substituted-2,2,2.
It has at least one 6,6-tetramethyl-4-piperidyl group in the molecule. X in formula (II)
Is alkyl, including methyl, ethyl, propyl and butyl, or methoxy, ethoxy, propoxy,
It is an alkoxy including butoxy, hexyloxy, octyloxy and the like, and in the case where each has 3 or more carbon atoms, it may be a straight chain or branched chain. Thus, in the present invention, a hindered piperidine compound in which the N-position of the piperidine ring is substituted with a specific group is used.

Although any compound having a group represented by the formula (II) can achieve the effect intended by the present invention, particularly preferable piperidine compounds are, for example, the following (C1) to (C3). ).

(C1) A compound represented by the following formula (III):

[0032]

[Chemical 8]

In the formula, X has the above-mentioned meaning. Specific examples of the compound contained in (C1) include bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate described in JP-A-58-90551 and JP-A-1-113.
And bis (2,2,6,6-tetramethyl-1-octyloxy-4-piperidyl) sebacate described in Japanese Patent No. 368.

(C2) A compound represented by the following formula (IV):

[0035]

[Chemical 9]

In the formula, X has the above-mentioned meaning. Specific examples of the compound contained in (C2) include tetrakis (1,
2,2,6,6-pentamethyl-4-piperidyl)
1,2,3,4-butane tetracarboxylate and the like can be mentioned.

(C3) A condensate of an aliphatic polyamine and a chlorotriazine compound represented by the following formula (V).

[0038]

[Chemical 10]

In the formula, X represents the above meaning, and Y represents hydrogen or alkyl having 1 to 4 carbon atoms. The alkyl represented by Y can be methyl, ethyl, propyl or butyl.

The aliphatic polyamine used for obtaining the condensate (C3) is an aliphatic compound having at least two primary or secondary amino groups in the molecule, and further 3
It may have a primary amino group, but it is particularly preferable that these amino groups are linked by alkylene, which is also linked by alkylene having about 2 to 18 carbon atoms. Specific examples of the aliphatic polyamine include 4,7-diazadecane-1,10-diamine, tris (2-aminoethyl) amine, 1,6,11.
-Triaminoundecane and the like.

Specific examples of the compound contained in (C3) include N, N ', which are described in JP-A No. 1-190678.
4,7-Tetrakis [4,6-bis {N-butyl-N-
(1,2,2,6,6-Pentamethyl-4-piperidyl) amino} -1,3,5-triazin-2-yl]-
4,7-diazadecane-1,10-diamine and the like can be mentioned.

The hindered piperidine compounds (C) described above may be used alone or in combination of two or more.

In the present invention, the above (A),
Each of the compounds (B) and (C) is an essential component, and the amount of each is 0.01 to 1 part by weight per 100 parts by weight of the polyolefin resin. These (A),
If the compounding amount of each of the compounds (B) and (C) is less than 0.01 part by weight, it is difficult to obtain the desired effect.
Further, even if the amount is more than 1 part by weight, the effect corresponding to the improvement cannot be obtained, which is economically disadvantageous. Within this range, the preferred amount of each compound used is about 0.02-0.5 parts by weight of the hindered phenolic compound (A),
The phosphorus compound (B) is about 0.02 to 0.5 part by weight,
The hindered piperidine compound (C) is 0.02-0.7.
It is about 5 parts by weight.

The polyolefin resin composition of the present invention is
In addition to the components described above, other additives, such as processing stabilizers, antioxidants, light stabilizers, metal soaps, nucleating agents, lubricants, neutralizing agents, and electrostatic charge, as long as their characteristics are not impaired. It may contain an inhibitor, a metal deactivator, a flame retardant, a pigment, an optical brightening agent and the like.

Specific examples of processing stabilizers that can be used include:
2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-3,5-di-
t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate and the like.

Specific examples of the metallic soaps include calcium stearate, zinc stearate, nickel stearate and the like. Specific examples of the lubricant include
Examples thereof include erucic acid amide, stearic acid amide, and stearic acid monoglyceride. Specific examples of the antistatic agent include quaternary ammonium salts and alkyl phosphates. Specific examples of the neutralizing agent include hydrotalcite and the like.

Specific examples of the flame retardant include halogen-containing phosphoric acid esters such as tris (2-chloroethyl) phosphate, halogen compounds such as hexabromocyclododecane and decabromodiphenyl oxide, antimony trioxide, pentavalent Examples thereof include metal-containing inorganic compounds such as antimony oxide and aluminum hydroxide.

As a method for blending the above-mentioned compounds (A), (B) and (C) used in the present invention, or other additives to be blended, if necessary, with a polyolefin resin, a uniaxial extruder is used. Alternatively, any method suitable for obtaining a homogeneous mixture can be used, such as kneading using a twin-screw extruder. Further, these raw materials may be blended at the same time, individually in a plurality of steps, or further, they may be mixed as a masterbatch.

The polyolefin resin composition of the present invention is
Although it can be used as a material for fibers, films, sheets and other molded articles, it is useful as a material for fibers and films, especially fibers.

The composition of the present invention can be made into fibers or films by various known methods. In the case of fibers, for example, a method of melt spinning and further stretching by a usual method, or a method of performing surface treatment with a finishing agent such as an oil agent and an antistatic agent after melt spinning and further stretching can be adopted. Further, in the case of forming a film, a method of forming into a film using an ordinary film extruder and simultaneously stretching depending on the purpose can be adopted.

[0051]

The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Parts and% in the examples represent parts by weight and% by weight, respectively, unless otherwise specified.

The test stabilizers used in the examples are as follows, and are indicated by respective symbols below.

Phenolic compound A-1: 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2 , 4, 8,
10-Tetraoxaspiro [5.5] undecane A-2: 1,3,5-Tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate A-3: Tetrakis [3- (3 , 5-Di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane A-4: bis (3,5-di-t-butyl-4-hydroxybenzylphosphonate ethyl) calcium

Phosphorus compound B-1: bis (2,4-di-t-butylphenyl)
Pentaerythritol diphosphite B-2: Tris (2,4-di-t-butylphenyl) phosphite B-3: Bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite B-4: Bis (2,4,6-tri-t-butylphenyl) pentaerythritol diphosphite B-5: Tetrakis (2,4-di-t-butylphenyl) 4,4'-biphenylene diphospho Night

Piperidine compound C-1: N, N ', 4,7-tetrakis [4,6-
Bis {N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino} -1,3,5-triazin-2-yl] -4,7-diazadecane-1,10
-Diamine C-2: Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate C-3: Bis (2,2,6,6-tetramethyl-1)
-Octyloxy-4-piperidyl) sebacate C-4: 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}] C-5: Polycondensate of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine C- 6: Bis (2,2,6,6-tetramethyl-4
-Piperidyl) sebate

Example 1

[Composition] Unstabilized polypropylene 100 parts Calcium stearate 0.05 parts Stabilizers listed in Table 1

After dry blending the above composition,
Cylinder temperature 210 ~ 22 in 40mmφ single screw extruder
The mixture was kneaded at 0 ° C and pelletized. 30 this pellet
mmφ extruder (die shape: 0.8 mmφ x 24 holes), cylinder temperature 220-250 ° C, discharge resin pressure 1
Melt spinning was performed under the conditions of 00 kgf / cm ² and a winding speed of 400 m / min to obtain an undrawn yarn. This undrawn yarn is
A fiber having a denier of 19 denier / filament was obtained by stretching at a temperature of about 3.3 times, and the following performance items were evaluated for this fiber.

(1a) Thermal oxidation resistance: The fibers obtained above were put in a gear oven at 150 ° C. and subjected to a tensile test every 100 hours. Then, the time until the tensile strength was reduced to 50% of the initial value was determined, and the stability to thermal oxidation was determined by the time until the tensile strength was reduced to half. In addition,
Within the 100-hour interval in which the tensile test was performed, the time was apportioned from the tensile strength values before and after. The longer the time until the tensile strength is reduced to half, the better the stability against thermal oxidation.

(1b) Photo-oxidation resistance: The fiber obtained above was put into a xenon fade meter according to SAE J 1885, and subjected to a tensile test at every energy irradiation amount of 100 kJ. Then, the amount of energy irradiation until the tensile strength was reduced to 50% of the initial value was determined, and the stability against photooxidation was determined by the amount of energy irradiation until the tensile strength was reduced to half. In addition, the energy dose 100
Within the interval of each kJ, the energy dose was apportioned from the tensile strength values before and after. The larger the amount of energy irradiation until the tensile strength is reduced to half, the more excellent the stability against photooxidation is.

(1c) Combustion gas discoloration resistance: The fiber obtained above was cut into a length of 5 cm, and about 3 g thereof was bundled at the center to obtain a test sample. This sample was exposed to city gas combustion gas at 60 ° C. for 20 hours in accordance with AATCC 23-1972, and the degree of discoloration was evaluated by visual judgment according to the following 5 grades. The smaller the value, the more excellent the resistance to discoloration.

[Criteria] 1: No discoloration 2: Slight discoloration 3: Medium to low discoloration 4: Slight discoloration 5: Large discoloration

(1d) NOx gas discoloration resistance: A sample similar to the above (1c) was prepared, and the NOx concentration was 2% by volume in accordance with JIS L 0855 "Test method for dye fastness to nitric oxide gas". Was exposed to the atmosphere for 24 hours, and the degree of discoloration was evaluated by visual judgment according to the same 5 grades as described in (1c). The smaller the value, the more excellent the resistance to discoloration.

Table 1 shows the above evaluation results. In the table, (1a) to (1d) in the result column correspond to the above performance evaluation items and are as follows.

(1a) Thermal oxidation resistance: 150 ° C. Tensile strength half-time (hrs) (1b) Photo-oxidation resistance: Tensile strength half-energy energy dose (kJ) (1c) Combustion gas discoloration resistance (1d) NOx gas discoloration resistance

[0066]

[Table 1]

Example 2

[Composition] Unstabilized polypropylene 100 parts Calcium stearate 0.05 parts Stabilizers listed in Table 2

After dry blending the above composition,
Cylinder temperature 220 ~ 23 in 30mmφ single screw extruder
The mixture was kneaded at 0 ° C and pelletized. This pellet 5.5
Cylinder temperature 230-24 by ounce injection molding machine
Molding was performed at 0 ° C. to obtain a No. 2 (1/2) type dumbbell type test piece conforming to JIS K 7113 and a sheet of 40 × 60 × 1 mm. The performance items shown below were evaluated using these dumbbell-shaped test pieces or sheets.

(2a) Thermal oxidation resistance: 1 dumbbell type test piece
It was placed in a gear oven at 60 ° C. and subjected to a tensile test every 120 hours. Then, the time until the tensile strength was reduced to 50% of the initial value was determined, and the stability to thermal oxidation was determined by the time until the tensile strength was reduced to half. In addition,
Within the 120-hour interval in which the tensile test was performed, the time was proportionally divided from the tensile strength values before and after. The longer the time until the tensile strength is reduced to half, the better the stability against thermal oxidation.

(2b) Photo-oxidation resistance: The above-mentioned sheet was put in a sunshine weather meter and irradiated with light under conditions of a black panel temperature of 63 ° C. and a water spray cycle of 18 minutes / 120 minutes, and the surface of the test piece every 60 hours. Was observed to measure the time (crack life) until a crack was generated on the surface of the test piece, and the stability against photooxidation was determined. The longer the crack life, the better the stability against photooxidation.

(2c) Combustion gas discoloration resistance: The above sheet was exposed to a city gas combustion gas at 98 ° C. for 4 hours, and the difference in yellowness index between test pieces before and after exposure (hereinafter referred to as ΔYI
Abbreviated) was evaluated to evaluate the degree of discoloration. ΔY
The smaller I is, the more excellent the color fastness is.

(2d) NOx gas discoloration resistance: The above sheet was exposed to an atmosphere having a NOx concentration of 2% by volume for 24 hours,
The ΔYI of the test piece before and after the exposure was measured to evaluate the degree of discoloration. The smaller ΔYI, the more excellent the resistance to discoloration.

Table 2 shows the above evaluation results. In the table, (2a) to (2d) in the result column correspond to the above performance evaluation items and are as follows. (2a) Thermal oxidation resistance: 160 ° C Tensile strength half time (hrs) (2b) Photo oxidation resistance: Crack life (hrs) (2c) Combustion gas discoloration resistance: ΔYI (2d) NOx gas discoloration resistance: ΔYI

[0075]

[Table 2]

[0076]

The composition obtained by blending a specific compound with a polyolefin resin according to the present invention has sufficient stability against heat, oxygen and light and is excellent in discoloration due to combustion gas or NOx gas. Shows good stability.

Claims (3)

[Claims] Claims: (A) The following formula (I): (In the formula, R represents hydrogen or alkyl having 1 to 3 carbon atoms) 0.01 to hindered phenol compound
1 part by weight; (B) bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di- t-butyl-4-methylphenyl)
Pentaerythritol diphosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol diphosphite, tetrakis (2,4-di-t-butylphenyl) 4,
4'-biphenylene diphosphonate, 2,2'-ethylidene bis (4,6-di-t-butylphenyl) fluorophosphite, and 2,2'-methylenebis (4,6-di-t-butylphenyl) ) 0.01 to 1 part by weight of a phosphorus compound selected from octyl phosphite; and (C) the following formula (II) (In the formula, X is alkyl having 1 to 4 carbons or 1 carbon
(Representing alkoxy of 8 to 8), and a N-substituted hindered piperidine compound (0.01 to 1 part by weight) having at least one group represented by the formula; . 2. A piperidine compound (C) is represented by the following compound groups (C1) to (C3): (C1) The following formula (III): (Wherein X represents the meaning described in claim 1); (C2) the following formula (IV): (Wherein X represents the meaning described in claim 1); (C3) an aliphatic polyamine and the following formula (V): (Wherein X represents the meaning described in claim 1 and Y represents hydrogen or alkyl having 1 to 4 carbon atoms), and a condensate with a chlorotriazine compound; object. 3. The composition according to claim 1, wherein the polyolefin resin is polypropylene.