JPH0243235A - Ultrahigh-molecular-weight polyolefin composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. having excellent heat stability and providing a molecularly oriented molding with excellent tensile strength, etc., by compounding an ultrahigh-MW polyolefin of a specified viscosity with specified amt. of a diluent and an org. phosphite stabilizer. CONSTITUTION:An ultrahigh-MW polyolefin compsn. is prepd. by mixing 3-80wt.% ultrahigh-MW polyolefin (A) having an intrinsic viscosity of 5-40dl/g as measured in decalin solvent at 135 deg.C (e.g., an ultrahigh-MW polyethylene), 97-20wt.% diluent (B) (e.g., paraffin wax) and 0.005-5 pts.wt. org. phosphite stabilizer [e.g., tris(2,4-di-t-butylphenyl) phosphite] based on 100 pts.wt. sum of the component A and B. As this compsn. scarcely undergoes thermal deterioration while molding, a molecularly oriented fiber, etc., obtd. by molding, exhibit excellent tensile strength, tensile elastic modulus, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an ultra-high molecular weight polyolefin composition suitable for obtaining a molecularly oriented molded article, and more specifically to an ultra-high molecular weight polyolefin composition that has excellent thermal stability during molding and long-term thermal stability. The present invention relates to an ultra-high molecular weight polyolefin composition for molding a molecularly oriented molded article.

Technical background of the invention and its problems It is already known that a molecularly oriented molded article having high tensile strength and high tensile modulus can be obtained by forming an ultra-high molecular weight polyolefin into a fiber, tape, etc. and then stretching it. ing. For example, Japanese Patent Publication No. 15408/1983 discloses a method of spinning a dilute solution of ultra-high molecular weight polyethylene and then drawing the resulting filament. Further, JP-A-59-130313 discloses a method in which ultra-high molecular weight polyethylene and wax are melt-kneaded, the kneaded product is extruded, the kneaded product is then cooled and solidified, and then stretched. Furthermore, JP-A-59-18761
Publication No. 4 discloses a method in which the molten mixture is extruded and then passed through a draft, and then the molten mixture is cooled, solidified, and stretched.

In this way, fibers using ultra-high molecular weight polyolefins,
When molding a molecularly oriented molded product such as a tape, a dilute solution of ultra-high molecular weight polyolefin is spun and the resulting filament is drawn, or a mixture of ultra-high molecular weight polyolefin and a diluent such as wax is melted. Operations such as extruding the mixed wire material after kneading, then cooling and solidifying the mixed wire material, and stretching the mixed wire material are required. During such operations, ultra-high molecular weight polyolefins may suffer from thermal stability during molding, such as being kept in a dilute solution at high temperatures for long periods of time, or undergoing thermal deterioration through extrusion in a high-temperature extruder. Because of the poor properties, the tensile strength, tensile modulus, etc. of the resulting molecularly oriented molded product were not necessarily sufficient.

Further, the above-mentioned ultra-high molecular weight polyolefin compositions all have a problem in that they are inferior not only in thermal stability during molding but also in long-term thermal stability.

Purpose of the Invention The present invention aims to solve one of the above-mentioned problems, and aims to provide a molecular orientation that does not impair the tensile strength, tensile modulus, etc. inherent in ultra-high molecular weight polyolefins. The object of the present invention is to provide an ultra-high molecular weight polyolefin composition that is suitable for obtaining a molded article and has excellent thermal stability during molding and long-term thermal stability.

Summary of the Invention The first ultra-high molecular weight polyolefin composition according to the present invention has (A) an intrinsic viscosity [η
Ultra-high molecular weight polio 1742 with a weight of 5 to 40 dN/g
23-80% by weight, and (B) diluent: 97-20% by weight.
and (C) organic phosphite stabilizer: It is characterized by comprising 0.005 to 5 parts by weight based on 100 parts by weight of the total weight of (A) ultra-high molecular weight polyolefin and (B) diluent.

Further, the second ultra-high molecular weight polyolefin composition according to the present invention has (A) an intrinsic viscosity [η
] is 5 to 40 dN/g, 3 to 80% by weight of an ultra-high molecular weight polyolefin, and (B) a diluent: 97 to 20% by weight.
and (C) organic phosphite stabilizer: 0.005 to 5 parts by weight based on 100 parts by weight of the total weight of (A) ultra-high molecular weight polyolefin and (B) diluent; (D) metal of higher fatty acid. Salt: It is characterized by consisting of 0.005 to 5 parts by weight based on 100 parts by weight of the total weight of (A) ultra-high molecular weight polyolefin and (B) diluent.

DETAILED DESCRIPTION OF THE INVENTION The ultra-high molecular weight polyolefin composition according to the present invention will be specifically described below.

Ultra-high molecular weight polyolefin (A) The intrinsic viscosity [η] of the ultra-high molecular weight polyolefin (A) used in the present invention measured in a decalin solvent at 135°C is:
It is at least 5 dN/g, preferably from 5 to 40 dΩ/g. If this intrinsic viscosity [η] is less than 5 dff/g, the obtained molecularly oriented molded product will not have sufficient tensile strength,
On the other hand, if it exceeds 40 dN/g, it is not preferable because it tends to become difficult to mold a molecularly oriented molded product.

The ultra-high molecular weight polyolefins (A) as described above include, for example, ethylene, propylene, 1-butene, ■-pentene, ■-hexene, ■-octene, ■-decene, 1-dodecene, 4-methyl-1-pentene, It consists of a homopolymer or copolymer of α-olefin such as 3-methyl-1-pentene. Among these, a homopolymer of ethyl chloride or a copolymer of ethylene and another α-olefin, with ethylene as the main component, is particularly preferred.

In the ultra-high molecular weight polyolefin composition according to the present invention, the ultra-high molecular weight polyolefin and the diluent (B) described below are such that the ultra-high molecular weight polyolefin (A) is the sum of both components (A) and (B). It is present in a proportion of 3 to 80% by weight. The ultra-high molecular weight polyolefin as described above is preferably present in a proportion of 15 to 60% by weight based on the total weight of component (A) and component (B). If the amount of the ultra-high molecular weight polyolefin (A) is less than 3% by weight, melt kneading becomes difficult and the stretchability of the molded product tends to be poor, which is undesirable. On the other hand, if it exceeds 80% by weight, the melt viscosity This is not preferable because it becomes too high, which makes melt-kneading or melt-molding difficult, and also causes the molded product to have a markedly rough surface and is prone to stretch breakage.

Diluent (B) The ultra-high molecular weight polyolefin composition according to the present invention contains a diluent (B) in addition to the above-mentioned ultra-high molecular weight polyolefin (A).

As the diluent, a solvent for ultra-high molecular weight polyolefin or various waxes having dispersibility for ultra-high molecular weight polyolefin are used.

The solvent used as the diluent (B) in the present invention is preferably a solvent having a boiling point higher than the melting point of the ultra-high molecular weight polyolefin, more preferably higher than the melting point +20°C.

Specifically, such solvents include n-nonane, n-
-dodecane, n-undecane, n-tetradecane, n-
Octadecane or liquid paraffin, aliphatic hydrocarbon solvents such as Toura, xylene, naphthalene, tetralin,
Aromatic hydrocarbon solvents such as butylbenzene, p-cymene, cyclohexylbenzene, diethylbenzene, pentylbenzene, dodecylbenzene, bicyclohexyl, decalin, methylnaphthalene, ethylnaphthalene or their hydrogenated derivatives, 1, 1, 2.2 -tetrachloroethane, pentachloroethane, hexachloroethane, 1,
2.3-trichloropropane, dichlorobenzene, 1,
Examples include halogenated hydrocarbon solvents such as 2.4-trichlorobenzene and bromobenzene, mineral oils such as paraffinic process oils, naphthenic process oils, and aromatic process oils.

Further, as the wax used as the diluent (B) in the present invention, an aliphatic hydrocarbon compound or a derivative thereof is used.

The aliphatic hydrocarbon compound is a paraffin wax mainly composed of a saturated aliphatic hydrocarbon compound, and usually has a molecular weight of 2,000 or less, preferably 1,000 or less, and more preferably 800 or less. Specifically, the following aliphatic hydrocarbon compounds are used.

N-alkanes with 22 or more carbon atoms such as tocosan, tricosane, tetracosane, and triacontane, or mixtures of these with lower n-alkanes as main components, so-called paraffin wax separated and refined from petroleum, ethylene or ethylene and other Polyethylene such as medium/low pressure polyethylene wax, high pressure polyethylene wax, ethylene copolymer wax, medium/low pressure polyethylene, high pressure polyethylene, etc., which are low molecular weight polymers obtained by copolymerizing with α-olefin, is thermally degraded. Waxes with lower molecular weights, oxides of these waxes, oxidized waxes modified with maleic acid, waxes modified with maleic acid, etc.

Examples of aliphatic hydrocarbon compound derivatives include one or more, preferably one to two, particularly preferably one, carboxyl group or hydroxyl group at the terminal or inside of an aliphatic hydrocarbon group (alkyl group, alkenyl group). , a compound having a functional group such as a carbamoyl group, an ester group, a mercapto group, or a carbonyl group having 8 or more carbon atoms, preferably 12 to 50 carbon atoms, or a molecular weight of 130 to 2,000, preferably 200 to 800 fatty acids, fats family alcohol,
Fatty acid amides, fatty acid esters, fatty/aliphatic mercaptans, aliphatic aldehydes, aliphatic ketones, etc. are used.

Specifically, the following compounds are used.

Fatty acids such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid, aliphatic alcohols such as lauryl alcohol, myristyl alcohol, cetyl alcohol, and stearyl alcohol, caprinamide, lauramide, valmitinamide, stearylamide, etc. Fatty acid amide, fatty acid ester such as stearyl acetate, etc.

In the ultra-high molecular weight polyolefin composition according to the present invention, the ultra-high molecular weight polyolefin and the diluent (B) are such that the diluent (B) is based on the total weight of both components (A) and (B). It is present in a proportion of 97 to 20% by weight. The diluent (B) as described above is preferably present in a proportion of 85 to 40% by weight based on the total weight of component (A) and component (B). Diluent (
If the amount of B) is less than 20% by weight, it is not preferable because the melt viscosity becomes too high, making it difficult to melt cross-wire or melt-molding, and the surface of the molded product is markedly rough, and it is likely to cause stretch breakage, etc. If it exceeds 97% by weight, it is not preferable because it becomes difficult to cross-wire the melt and the stretchability of the molded product tends to be poor.

Organic phosphite stabilizer (C) The ultra-high molecular weight polyolefin composition according to the present invention contains an organic phosphite stabilizer (C) in addition to the ultra-high molecular weight polyolefin (A) and diluent (B) as described above. ).

As the organic phosphite stabilizer, conventionally known stabilizers can be used without particular limitation, and specifically, the following compounds are used.

Trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl-diphenyl phosphite, tris(2,4-di-t-butylphenyl)
Phosphite, triphenyl phosphite, tris(butoxyethyl) phosphite, tris(nonylphenyl) phosphite, distearylpentaerythritol diphosphite, tetra(tridecyl)-1,1,3 but tris(2-methyl-5) -1-butyl-4-hydroxyphenyl)butane diphosphite, tetra(C12-C
15 mixed alkyl)-4,4'-isopropylidene diphenyl diphosphite, tetra(tridecyl)-4,
4°-Butylidenebis(3-methyl-et-t-butylphenol) diphosphite, tris(8,5-di-t-
Butyl-4-hydroxyphenyl) phosphite, tris(mono-dimixed nonylphenyl) phosphite, hydrogenated-4,4゛-isopropylidene diphenol polyphosphite, bis(octylphenyl) bis[4,4°
-butylidenebis(3-methyl-et-butylphenol)]-1,8-hexanediol diphosphite,
Phenyl・4,4°-isopropylidenediphenol・
Pentaerythritol diphosphite, tris[4,4
゜-Isopropylidene bis(2-t-butylphenol) cophosphite, phenyl diisodecyl phosphite, di(nonylphenyl)pentaerythritol diphosphite, tris(1,3-di-stearoyloxyisopropyl) phosphite, 4.4 °-isopropylidenebis(2-t-butylphenol)-di(nonylphenyl)phosphite, 9.10-di-hydro-9-oxa-9-oxa-10-phosphaphenanthrene-IO
- Examples include oxides.

Further, as the bis(dialkylphenyl)pentaerythritol diphosphite ester, a spiro type represented by the following formula (1) or a cage type represented by the formula (2) are also used. Mixtures of both isomers are usually used most often for economic reasons arising from the process of preparing such phosphite esters.

Here, RR2 is preferably an alkyl group having 1 to 9 carbon atoms, particularly a branched alkyl group, and particularly preferably a t-butyl group, and its substitution position in the phenyl group is most preferably at the 2, 4, and 6 positions. Suitable phosphite esters include bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis[2,6-di-t-butyl-
4-methylphenyl) pentaerythritol diphosphite, and also phosphonites with a structure in which carbon and phosphorus are directly bonded, such as tetrakis(2,4-di-t-butylphenyl)-4,4-biphenylene diphosphite. Compounds such as phonite may also be mentioned.

These organic phosphite stabilizers may be used alone or in combination.

In the ultra-high molecular weight polyolefin composition according to the present invention, the organic phosphite stabilizer (C) as described above is added to 100 parts by weight of the total weight of the ultra-high molecular weight polyolefin (A) and the diluent (B). 0.005 to 5 parts by weight, preferably 0.01 to 0.5 parts by weight, more preferably 0.05 parts by weight
It is used in an amount of ˜0.2 parts by weight. The amount of this organic phosphite stabilizer (C) is
) and diluent (B), based on 100 parts by weight of the total weight.
．． If it is less than 0.005 parts by weight, the effect of improving heat resistance will be low, which is undesirable, while if it exceeds 5 parts by weight, not only will the cost of the stabilizer increase, but the properties of the resin, such as strength and elongation, will be impaired. This is not desirable due to the risk.

Metal salt of higher fatty acid (D) The ultra-high molecular weight polyolefin composition according to the present invention comprises the above-mentioned ultra-high molecular weight polyolefin (A), a diluent (B
) and an organic phosphite stabilizer (C), it contains a metal salt of a higher fatty acid (D).

Examples of metal salts of higher fatty acids include stearic acid, oleic acid, lauric acid, capric acid, araxic acid, palmitic acid, behenic acid, 12-hydroxystearic acid,
Magnesium salts, calcium salts, alkaline earth metal salts such as barium salts, cadmium salts, zinc salts, lead salts, sodium salts of higher fatty acids such as ricinoleic acid and montanic acid,
Alkali metal salts such as potassium salts and lithium salts are used. Specifically, the following compounds are used.

Magnesium stearate, magnesium laurate,
Magnesium palmitate, calcium stearate,
Calcium oleate, calcium laurate, barium stearate, barium oleate, barium laurate, barium araxinate, barium behenate, zinc stearate, zinc oleate, zinc laurate, stearate, sodium stearate, palmitic acid Sodium, sodium laurate, potassium stearate, potassium laurate, calcium 12-hydroxystearate, calcium montanate, etc.

These metal salts of higher fatty acids may be used alone or in combination.

In the ultra-high molecular weight polyolefin composition according to the present invention, the metal salt of higher fatty acid (D) as described above is added to the ultra-high molecular weight polyolefin (A) and the diluent (B) in a total amount of
0.005 to 5 parts by weight, preferably 0.005 to 5 parts by weight.
0.01 to 0.5 parts by weight, more preferably 0.05 to 0.05 parts by weight.
It is used in an amount of 5 parts by weight. Metal salts of this higher fatty acid (
The amount of ultra-high molecular weight polyolefin (A) and dilute [IJ
0.005 for 11,100 parts by weight of total mold with (B)
If it is less than 5 parts by weight, residual chlorine in the polymer derived from the catalyst will not be absorbed sufficiently, causing resin deterioration, which is undesirable, while if it exceeds 5 parts by weight, the cost of the stabilizer will only increase. First, it is not preferable because there is a risk that the properties of the resin, such as tensile elongation, etc., may be impaired.

The metal salts of higher fatty acids as described above have effects as lubricants and antirust agents, so the ultrahigh molecular weight polyolefin composition according to the present invention has excellent moldability and is effective in preventing rust in molding machines, etc. .

In addition to the above-mentioned components (A), (B), (C) and (D), the ultra-high molecular weight polyolefin composition according to the present invention includes, for example, heat stabilizers, weather stabilizers, pigments, dyes, lubricants, Compounding agents such as antistatic agents that are usually added to polyolefins can be added within the range that does not impair the purpose of the present invention.

Effects of the Invention The ultra-high molecular weight polyolefin composition according to the present invention has excellent thermal stability during molding and long-term heat resistance stability, and suffers little thermal deterioration when molding molecularly oriented molded articles such as fibers and tapes. It can be used to produce molecularly oriented molded articles having high tensile strength, high tensile modulus, etc.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Ultra-high molecular weight polyethylene (intrinsic viscosity [η] -8,94d
l/g, l in decalin solvent at 135°C! Y1 constant) Powder 2
Tris (2,4-di- t-butylphenyl) phosphite) (manufactured by Ciba Geigy Field Japan, product name: PIIOSPI)
0.1 weight part of IITE 1811> was combined and melt-spun under the following conditions.

The mixture was extruded using a screw extruder (screw diameter 25 m,
L/D-25, manufactured by Thermoplastics),
After melt-kneading at a set temperature of 190° C., the melt was melt-spun using a spinning die with an orifice diameter of 2 ml attached to an extruder. The extruded melt was then withdrawn under the conditions of an air gap of 180 cm and a draft ratio of 35 times,
It was cooled and solidified in air to obtain undrawn fibers.

Furthermore, the undrawn fibers were drawn under the following conditions to obtain molecularly oriented fibers.

Two-stage stretching was performed using a Godetstrol made by Ohdai. At this time, the heating medium in the first drawing tank was n-decane at a temperature of 110°C, and the heating medium in the second drawing tank was triethylene glycol at a temperature of 145°C. The effective length of each tank was 50 cm. During stretching, the rotation speed of the first godet roll was 0.5/min, and the rotation speed of the third godet roll was 12.5/min (stretching ratio: 25 times).

The rotational speed of the second godet roll was appropriately selected within a range that allowed stable operation. Almost all of the initially mixed paraffin wax was extracted into n-decane during stretching.

Next, the obtained molecularly oriented fibers were washed with water, dried under reduced pressure at room temperature for a day and night, and subjected to measurements of intrinsic viscosity [η] and tensile properties. These measurement methods are as follows.

Intrinsic viscosity [η]: Intrinsic viscosity of the resin constituting the molecularly oriented fibers measured in a decalin solvent at 135°C. The measurement was performed at room temperature (23°C). At this time, the number of testers between the clamps was 100, and the tensile rate was 100/min (100% strain rate). The elastic modulus was calculated using the slope of the tangent at the initial elastic modulus. The fiber cross-sectional area required for calculation is density 0.960
It was calculated from the weight as g/cc.

The results are shown in Table 1.

Example 2 In Example 1, as the organic phosphite stabilizer,
Tris (2,4-di-t-butylphenyl) phosphite) (manufactured by Ciba Geigy Japan, trade name PIIO8PI)
Molecularly oriented fibers were prepared in the same manner as in Example 1, except that 0.1 part by weight of IITE L68) was used and 0.3 part by weight of calcium stearate (manufactured by Sankyoki ■) was added as a higher fatty acid metal salt. was obtained, and the above I) determination was performed.

The results are shown in Table 1.

Example 3 In Example 1, as an organic phosphite stabilizer,
Bis(2,4-di-t-butyl-phenyl)pentaerythritol diphosphite (manufactured by Bogwana Co., Ltd.,
Product name: ULTRANOX 826) Wo0. Molecularly oriented fibers were obtained in the same manner as in Example 1, except that 1 part by weight was used, and the above measurements were performed.

The results are shown in Table 1.

Example 4 In Example 1, as the organic phosphite stabilizer,
Bis(2,4-di-t-butyl-phenyl)pentaerythritol diphosphite (manufactured by Borgner Co., Ltd.,
The same procedure as in Example 1 was carried out, except that 0.1 part by weight of ULTRANOX 82B (trade name: ULTRANOX 82B) was used, and 0.3 parts by weight of calcium stearate (manufactured by Sankyoki ■) was added as a higher fatty acid metal salt. Molecularly oriented fibers were obtained and the measurements described above were performed.

The results are shown in Table 1.

Example 5 In Example 1, as the organic phosphite stabilizer,
Bis(2,6-di-t-butyl-4-methylphenyl)
Hepentaerythritol diphosphite (manufactured by Adeka Argus ■, product name: MARK PEP-36) at 0.1
The above measurements were carried out using the molecularly oriented fibers in the same manner as in Example 1, except that part by weight was used.

The results are shown in Table 1.

Example 6 In Example 1, as the organic phosphite stabilizer,
Bis(2,6-di-t-butyl-4-methylphenyl)
Using 0.1 part by weight of pentaerythritol diphosphite (manufactured by Adeka Argus ■, product 82M^RK PPP-36), and further adding 0.3 parts by weight of calcium stearate (manufactured by Sankyoki ■) as a higher fatty acid metal salt. Molecularly oriented fibers were obtained in the same manner as in Example 1, except that part by weight was added, and the above measurements were performed.

The results are shown in Table 1.

Example 7 In Example 1, as an organic phosphite stabilizer,
Trisnonylphenyl phosphite (azocaf-7'/
Made by Sfl, product name: MARK 329). Molecularly oriented fibers were obtained in the same manner as in Example 1, except that 1 part by weight was used, and the above measurements were performed.

The results are shown in Table 1.

Example 8 In Example 1, as the organic phosphite stabilizer,
Trisnonylphenylphosphite (Atefy 7-f
f Made by Im, product name: MARK 329) at 0.
Molecularly oriented fibers were obtained in the same manner as in Example 1, except that 0.3 parts by weight of calcium stearate (manufactured by Sankyoki ■) was used as a higher fatty acid metal salt, and the above measurements were carried out. I did it.

The results are shown in Table 1.

Example 9 In Example 1, as the organic phosphite stabilizer,
Tetrakis (2,4-di-t-butylphenyl) 4.4
- Biphenylene phosphonite (manufactured by Sandoz, product name:
Molecularly oriented fibers were obtained in the same manner as in Example 1, except that 0.1 part by weight of 5ANDO3TAB P-EPQ) was used, and the above measurements were performed.

The results are shown in Table 1.

Example 10 In Example 1, as an organic phosphite stabilizer,
Tetrakis (2,4-di-t-butylphenyl) 4.4
Using 0.1 part by weight of °-biphenylene phosphonite (manufactured by Sandoz Co., Ltd., trade name: 5ANDO3TAB P-EPQ), further, 0.3 part by weight of calcium stearate (manufactured by Sankyoki ■) as a higher fatty acid metal salt. The molecularly oriented fibers were added in the same manner as in Example 1 except that 1F4,
The above measurements were carried out.

The results are shown in Table 1.

Comparative Example 1 Molecularly oriented fibers were obtained in the same manner as in Example 1, except that the organic phosphite stabilizer was not used, and the above measurements were performed.

The results are shown in Table 1.

From an ultra-high molecular weight polyethylene composition containing a surface stabilizer, molecularly oriented fibers with good tensile properties and less decrease in intrinsic viscosity [η] due to molding can be obtained.

Claims (1)

[Claims] 1) (A) 3 to 80% by weight of an ultra-high molecular weight polyolefin having an intrinsic viscosity [η] of 5 to 40 dl/g measured in a decalin solvent at 135°C; (B) a diluent: and (C) organic phosphite stabilizer: 0.005 to 5 parts by weight based on 100 parts by weight of the total weight of (A) ultra-high molecular weight polyolefin and (B) diluent. An ultra-high molecular weight polyolefin composition characterized by: 2) (A) ultra-high molecular weight polyolefin having an intrinsic viscosity [η] of 5 to 40 dl/g measured in a decalin solvent at 135°C: 3 to 80% by weight; (B) a diluent: 97 to 20% by weight. , (C) organic phosphite stabilizer: 0.005 to 5 parts by weight per 100 parts by weight of the total weight of (A) ultra-high molecular weight polyolefin and (B) diluent, and (D) metal salt of higher fatty acid. : An ultra-high molecular weight polyolefin composition comprising 0.005 to 5 parts by weight based on 100 parts by weight of the total weight of (A) ultra-high molecular weight polyolefin and (B) diluent.