JPS59122546A - Polyamide composition - Google Patents

Abstract

PURPOSE:To provide the titled composition having remarkably improved rigidity, low-temperature impact resistance, salt water resistance, etc., and having excellent moldability, by compounding a polyamide with specific amounts of a specific modified ethylene-alpha-olefin-diene elastic copolymer and specific crystalline ethylenic polymer. CONSTITUTION:The objective composition is prepared by compounding (A) 100pts.wt. of a polyamide with (B) 1-100pts.wt. of a modified ethylene-alpha-olefin- diene elastic copolymer composed of 0.01-10pts.wt. of an unsaturated carboxylic acid or its derivative component unit grafted to 100pts.wt. of an ethylene-alpha- olefin-diene elastic copolymer, and having a crystallinity of <=40% and a melt flow rate (190 deg.C) of 0.01-50g/10min, and (C) 1-200pts.wt. a crystalline ethylenic polymer composed mainly (>=70mol%) of ethylene unit and having a melt flow rate (190 deg.C) of 0.01-50g/10min.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyamide resin composition that has excellent rigidity, low-temperature box impact resistance, salt water resistance, and moldability.

Polyamide resin is expected to be in great demand as an engineering plastic due to its excellent physical properties.

However, performance such as low-temperature impact resistance, water resistance, and salt water resistance is not sufficient, and improvements are desired. As a method for improving impact resistance such as Izot impact strength, for example, Japanese Patent Publications No. 12546/1982 and Japanese Patent Publication No. 441/1982
No. 08, JP-A-55-9661, JP-A-Sho 55
Prior art documents such as Publication No. 9662 describe a method of blending a modified α-olefin elastic polymer such as an ethylene/(r-olefin copolymer) grafted with a, β-unsaturated carboxylic acid into a polyamide resin. In all of the compositions proposed in these prior art documents, when the impact resistance such as Izotsu ship impact strength is improved, the rigidity decreases significantly, and furthermore, the falling weight impact strength at low temperatures also deteriorates. However, these compositions have the disadvantage that it is difficult to obtain actual molded products with high rigidity and high impact resistance.Furthermore, these compositions often have too low melt flowability, and depending on the molding method, molding may be difficult. They also have the disadvantage of reduced processability.Furthermore, these compositions have poor water resistance, particularly hydrolysis resistance, under conditions of contact with salt water such as various alkali metal salts or alkaline earth metal salts; Its use was also limited in fields where it was required, particularly in automobile parts.

In addition, as a method for improving water resistance such as hygroscopicity or salt water resistance of polyamide resin, Japanese Patent Application Laid-Open No. 55-8001
Publication No. 4, JP-A-56-167751, JP-A-5
No. 6-109247 and JP-A-56-157451 disclose that ethylene and α
, a method of blending a neutralized β-unsaturated monocarboxylic acid copolymer (ionomer resin) has been proposed. Although the compositions proposed in these prior art documents can improve water resistance such as water absorption and salt water decomposition resistance, they have a drawback in that they are inferior in the effect of improving low-temperature impact resistance.

Furthermore, as a method for improving the decrease in rigidity of the above-mentioned polyamide resin composition, JP-A-57-8246 discloses a graft modified product of a composition of +A crystalline polyolefin and an ethylene/α-olefin elastic copolymer. A method of blending has been proposed. However, in this method, the modified polyolefin in the graft modified product and modified ethylene/α-
It is difficult to control the melt fluidity of each olefin elastic copolymer, and as a result, it becomes impossible to obtain a polyamide composition with good dispersibility, and the temperature range for improving impact resistance becomes extremely narrow, and the improvement effect is also small. In particular, there are disadvantages in that the low-temperature Izotl[i'M strength and falling weight impact strength at temperatures below -20 DEG C. are significantly lowered, and the melt flowability of the composition is also lowered.

Furthermore, among the prior art documents mentioned above, Japanese Patent Application Laid-Open No. 55-562
No. 79 discloses that, as mentioned above, when blending a modified ethylene/α-olefin elastic copolymer to improve the impact resistance of polyamide, an unmodified ethylene/α-olefin elastic copolymer is also added. When blended with polyamide, a polyamide composition with improved appearance and color tone can be obtained, and the proportion of expensive modified ethylene/α-olefin elastomeric copolymer used can be reduced, so it is also economically effective. It is stated that. However, according to the description of the publication, especially the description of Examples and Comparative Examples, it is clear that a modified ethylene/α-olefin elastomeric copolymer and an unmodified ethylene/α-olefin elastomeric copolymer blended into polyamide Considering the effect of improving the impact resistance of polyamide compositions obtained by changing the toner composition, compared to the experiment in which unmodified ethylene/α-olefin elastic copolymer was blended alone (Comparative Example 1), However, compared to the experiment (reference example) in which the modified ethylene/α-olefin elastic copolymer was blended alone, the M resistance was improved! J impact resistance is only improved in proportion to the blending ratio of the modified ethylene/α-olefin elastic copolymer, and the amount of the modified ethylene/α-olefin elastic copolymer used should be reduced. This has only been achieved through economic effects.

As a result of testing for the development of polyamide compositions with excellent performance, the present invention was developed based on modified ethylene, α-olefin,
By blending a diene elastic copolymer and a crystalline ethylene-based polymer into a polyamide in a specific range to form a composition, the modified There is a synergistic effect in the blending of the ethylene-α-olefin/diene elastomeric copolymer and the crystalline ethylene-based polymer, and there is only the effect of reducing the amount of the modified ethylene/α-A refine/diene elastomeric copolymer used. We have discovered that this is not the case, and have arrived at the present invention.

According to the present invention, the polyamide composition of the present invention has improved impact properties such as isot impact strength and falling weight impact strength at low temperatures, stress crack resistance, and has improved water absorption and salt water decomposition resistance under salt water conditions. Water resistance has been significantly improved, and this composition has the characteristics of excellent molding processability because there is little decrease in melt flowability.

To summarize the present invention, the present invention comprises polyamide (A), modified ethylene/a-olefin C diene elastic material "6t<'
A polyamide composition comprising a crystalline ethylene polymer (B) and a crystalline ethylene polymer (C), wherein the composition of each component in the composition is different from that of the polyamide (A
) 100 parts by weight so that the modified ethylene/α-olefin/diene elastic copolymer (D) is in the range of 1 to 100 parts by weight, and the crystalline ethylene polymer (C) is in the range of 1 to 200 parts by weight. 1 [11] The modified ethylene/α-olefin/diene bomb'
6 copolymer (B) 6s/base ethylene/α-olefin/diene elastomeric copolymer 10 parts by weight The melt flow rate ( ) / I F F! is made by a range of raft copolymerization, and its crystallinity is 40% or less. 1
96C) is in the range of 0.01 to 50 g/10 min, and C! ! The crystalline ethylene polymer (C) is mainly composed of ethylene component units, and has a melt flow rate [MFR19°・C] of 0.01 to 190°C. 50 g/10 min.

The polyamide (A) used in the polyamide composition of the present invention has a molecular weight sufficient to produce a molded article, and is a saturated organic dicarboxylic acid having 4 to 12 carbon atoms. It can be produced by combining 4 equimolar amounts of 2 L/) and an organic diamine having 134 carbon atoms. Here, if necessary, diamine can be used in the polyamide so that the amino group ends are in excess compared to the carboxyl group ends, or conversely, dicarboxylic acid can be used so that the carboxyl groups are in excess. can. These polyamides can also be produced from the amine and acid-forming derivatives and amine-forming derivatives, such as esters, acid chlorides, amine salts, and the like. Typical dicarboxylic acids used to make polyamides include adipic acid, pimelic acid, superric acid, sebacic acid and dodecandioic acid. On the other hand, typical diamines include hexamethylene diamine and octamethylene diamine. Furthermore, polyamides can also be produced by self-condensation of lactams. Examples of polyamides include polyhexamethylene adipamide (6,6 nylon), polyhexamethylene adipamide (6,9 nylon), polyhexamethylene sebaamide (6,10 nylon), and polyhexamethylene Dodeca/amide (6,12 nylon), polybis(4-aminocyclohexyl)methandodecanamide, or polyamides produced by ring opening of lactams, i.e. polycaprolactam (6,12 nylon), polymaurilactam or poly-11 -There is aminoundecanoic acid. at least two used to produce said polyamide
By polymerization of species 7-mine or acids? It is also possible to use polyamides manufactured by JM, for example polymers made from adipic acid and isophthalic acid and dichloromethane diamine. It is also possible to use blends of polyamides such as nylon 6.6 and mixtures of nylon 6. The condensed polyamide used in the present invention is preferably polyhexamethylene adipamide (6,6 nylon) or polyhexamethylene aceramide (6,9 nylon) and polycaprolactam (6,9 nylon). be.

Modified ethylene compounded in the polyamide composition of the present invention
α-olefin/diene elastomeric copolymer (B) (c) Base: 0.01 to 10 parts by weight of an unsaturated carboxylic acid or its derivative component unit per 100 parts by weight of the ethylene/α-olefin/diene elastomeric copolymer. The crystallinity is in the range of 40% or less, and the melt flow rate (MFR:) at 190°C is in the range of 0.01 to 50190°C g/10m1n. In addition, the base ethylene eα-olefin hacyene elastic copolymer 1
0.00 parts by weight of unsaturated carboxylic acid or its derivative component units in the range of 0.05 to 5 parts by weight, the degree of crystallinity is in the range of 1 to 60%, and 190% by weight. Melt flow rate +- in °C
, CMF'j'9c, c] is 0.05 to 20 g/1
It is preferably in the range of 0 m1n. Furthermore, other physical properties of the modified ethylene/a-olefin/diene elastic copolymer (B) include a molecular weight distribution (M-VV/Mn) usually in the range of 1.5 to 50, preferably 3 to 20; The glass transition temperature is usually -10°C or lower, preferably -20°C or lower. The modified ethylene (Y
- The grafting ratio of unsaturated carboxylic acid or its derivative component units in the olefin-diene elastic copolymer is 0.01
When it is less than 10 parts by weight, the compatibility with polyamide becomes poor and the impact strength of the polyamide composition decreases.
When the amount exceeds 1 part by weight, the degree of crosslinking of the graft modified product increases, and the effect of improving the impact resistance of the composition decreases even when blended with polyamide. The modified ethylene α
-Crystallinity of olefin-diene elastic copolymer is 40%
When the size is larger, the impact resistance of the polyamide composition becomes irregular, and the melt flow rate becomes 0.0.
If it is less than 1 g/10 m1n, the impact resistance and melt flowability of the polyamide composition will decrease, and if it is greater than 50 g/10 + nin, the impact resistance will decrease.

The base polymer constituting the modified ethylene/α-olefin/diene elastic copolymer is ethylene or 0-
It is a random copolymer of olefin and diene components and is an elastic copolymer with low crystallinity. Its composition is such that the content of the ethylene component is usually 95 to 65 mol%, preferably 90 to 40 mol%, and the content of the 0-olefin component is usually 5 to 65 mol%, preferably 10 to 60 mol%.
The mole % and diene component content are usually in the range of 0.05 to 15 mole %, preferably 0.5 to 10 mole %. Further, its crystallization rate is usually 40% or less, preferably 30% or less, and its melt flow rate (114FR) is usually 0.01 to 190°C 50 g/10 m1n, preferably 0.05 to 2
0 g/10 r++j,,n, and its glass transition temperature is usually -10°C or lower, preferably -20°C or lower.
The range is below °C. □- other than ethylene constituting the base ethylene/α-olefin/diene elastic copolymer
Examples of the olefin component unit include (propylene) 1-butene, 1-benzone, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and the like. In addition, as diene component units, 1,4-hexadiene, dicyclopentadiene, 5-
Non-conjugated diene components such as ethylidene-2-norbornene and 2,5-turbonasien, butadiene, isoprene,
Examples include conjugated diene components such as piperylene, but non-conjugated diene components are preferred.

Specifically, the base ethylene/alpha-olefin/diene elastomeric copolymer includes ethylene/propylene/1,4-hexadiene copolymer, ethylene/propylene/dicyclopentadiene copolymer, ethylene・Propylene/5-ethylene-2-norbor/7, polymer, ethylene/propylene/2,5-turbonasiene copolymer, ethylene/1-butene/1,4-hexadiene copolymer, ethylene/1-butene Examples include dicyclopentadiene copolymer, ethylene/1-butene/5-ethylidene-2-norbornene copolymer, and the like.

Examples of the unsaturated carboxylic acid or its derivative component unit of the graft monomer component constituting the modified ethylene/tI-olefin/diene elastic copolymer (B) include acrylic acid, methacrylic acid/α-ethyl acrylic acid, and maleic acid. , fumaric acid, itaconic acid, citraconic acid 1-tetrahydrophthanoic acid, methyltetrahydrophthalic acid,
Endocys-bicyclo(2,2,1)hept-5-ene-2,3-dicarboxylic acid (Nadic?), Methyl-endocys-bicyclo(2,2,1)hept-5-ene-2
, unsaturated dicarboxylic acids such as 3-dicarboxylic acid (methylnadic acid 0), acid halides of the unsaturated dicarboxylic acids,
Examples include derivatives of unsaturated dicarboxylic acids such as amides, imides, anhydrides, and esters; specific examples include maleyl chloride, maleimide, maleic anhydride, citrafunic anhydride,
Examples include monomethyl maleate, dimedyl maleate, and glycidyl maleate. Among these, unsaturated dicarboxylic acids or their acid anhydrides are preferred, and maleic acid, nadic acid, or their acid anhydrides are particularly preferred.

A Relcraft monomer selected from the unsaturated carboxylic acids or derivatives thereof is graft copolymerized to the ethylene/a-olefin and diene elastic copolymer to obtain the modified ethylene/α-
Various conventionally known methods can be used to produce the olefin/r/n/diene elastic copolymer. For example, there is a method of melting an ethylene/α-olefin/diene elastic copolymer and adding a graft monomer to carry out graft copolymerization, or a method of dissolving the ethylene/α-olefin/diene elastic copolymer in a solvent and adding a graft monomer to carry out graft copolymerization. In any case, in order to efficiently graft copolymerize the graft monomer, it is preferable to carry out the reaction in the presence of a radical initiator. Grafting reaction is usually 60 to 350
°C (d temperature).

The proportion of the radical initiator to be used is approximately 0.00 parts by weight per 100 parts by weight of the ethylene/V-olefin/diene elastomeric copolymer.
The range is from 0.01 to 20 parts by weight. As a radical initiator, organic peroxide, organic bereester2. Azo compounds and the like are used.

The crystalline ethylene polymer (C) blended into the polyamide composition of the present invention is an ethylene homopolymer or a copolymer containing ethylene as a main component and an α-olefin other than ethylene, and is a crystalline ethylene polymer. It is an ethylene polymer whose melt temperature at 190°C is 70°C (MFi()
is required to be in the range of 0.01 to 190° C. 50 g/10 m1n, and more preferably in the range of 0.05 to 2'Og/10 min. Regarding other physical properties of the crystalline ethylene polymer, the ethylene content is usually 70 mol%.
The crystallinity is usually 50% or more, preferably 6o to 95%.
The melting point is usually in the range of 6o to 135'C,
It is preferably in the range of 80 to 1300C, and its density is usually in the range of 0.90 to 0.98 g/cm3, preferably 0.92 to 0.97 g/Orl'.

Melt flow rate ("R") of the crystalline ethylene polymer
? 9oc) is less than O-01 g/10 min, the impact resistance and melt flowability of the polyamide composition will decrease, and if it is greater than 50 g/10 min, the impact resistance will decrease.

When the crystalline PfE ethylene polymer is an ethylene/α-olefin copolymer, the α-olefin component units include propylene, 1-phthene, 1-bentene, 4-
Methyl-1-pentene, 1-hexene, 1-octene,
Examples include 1-decene and 1-totycene.

In the polyamide composition of the present invention, the modified ethylene
When blending the α-olefin/diene elastic copolymer (B) and the crystalline ethylene polymer (C) into polyamide, the melt flow rate of both at 190°C [8! The ratio of IFR:), 19+]”c (JV!PR)/(MFR) 190°C 190°C, is usually adjusted to a range of 0.01 to 100, and further adjusted to a range of 0.5 to 50. It is preferable.

In the polyamide composition of the present invention, the polyamide (
The ratio ViJ of the modified ethylene/α-olefin/diene elastomeric copolymer (B) to 100 parts by weight of A) must be in the range of 1 to 100 parts by weight;
It is preferably in the range of 5 to 80 parts by weight, particularly preferably 5 to 50 parts by weight. The modified ethylene content α-
If the blending ratio of the melefin/diene elastomeric copolymer exceeds 100 parts by weight, the rigidity and melt flowability of the polyamide composition will decrease, and if it becomes less than 1 part by weight, the impact resistance and resistance of the polyamide composition will decrease. Stress crack resistance and water resistance begin to deteriorate. Further, the blending ratio of the crystalline ethylene polymer (C) to 100 parts by weight of the polynamide (A) needs to be in the range of 1 to 200 parts by weight, and more preferably 5 to 15 parts by weight.
Preferably, the amount is in the range of 0 parts by weight.

When the blending ratio of the crystalline ethylene polymer exceeds 200 parts by weight, the rigidity and melt flowability of the polyamide composition decrease, and when it becomes less than 1 part by weight, the impact resistance of the polyamide composition decreases. , stress crack resistance and water column resistance are reduced. Further, in the polyamide composition of the present invention, the blending ratio of the crystalline raw ethylene polymer (0) to 100 parts by weight of the modified ethylene/α-olefin-diene elastic copolymer (E) is usually 5 to 2000 parts by weight. parts, preferably 10 to 1
The range is 501:1ffi parts. Furthermore, in the polyamide composition of the present invention, the modified ethylene α
- The ratio of the graft-copolymerized unsaturated carboxylic acid or its derivative component units to the total amount of the olefin/diene elastic copolymer (B) and the crystalline ethylene polymer (C) is usually 0.02 to 7% by weight %, preferably in the range of 0.05 to 5% by weight.

In addition to the above-mentioned three essential components, the polyamide composition of the present invention may optionally contain an antioxidant, an ultraviolet absorber, a photoprotectant,
Phosphite stabilizer, peroxide decomposer, basic adjuvant, nucleating agent, plasticizer, lubricant, antistatic agent, flame retardant, pigment, dye, carbon black, asbestos, glass fiber, potassium titanate whisker , mica, carrion, talc, silica,
It is also possible to incorporate fillers such as silica alumina.

Furthermore, other polymers may be blended into the composition of the present invention within a range that does not impair its physical properties. The blending ratio of these additives is within an appropriate range.

The polyamide compositions of the present invention are prepared by melt mixing in a variety of ways. For example, two essential components may be premixed and then mixed with the remaining components, or three essential components may be mixed with other remaining components at the same time. Moreover, the above-mentioned additives, such as antioxidants, can be added at any of these stages as necessary.

The polyamide composition of the present invention has excellent properties such as rigidity, impact resistance, and water resistance. Among these, the fJI composition obtained by melt-mixing the polyamide (A) component into a premix prepared by melt-mixing the component (B) and the component (Cj) during production of the composition has particularly high performance. Are better.

Melt flowability (melt flow rate) of the composition of the present invention (
b, rllPR,' 235°C, 1000, g load)
] is usually 0.1 to 500 g/10m1n,
Preferably it is in the range of 0.2 to 100 g/10 m1n.

The polyamide composition of the present invention can be molded into various shapes by various conventionally known melt molding methods. Examples include methods such as injection molding, extrusion molding, compression molding, and foam molding, and are used for a wide range of applications including automobile parts, electrical appliances, and electrical parts.

Next, the present invention will be specifically explained using examples. In addition, in Examples and Comparative Examples, crystallinity and 190'
Melt flow rate CMFR19o at C. ] was measured by the following method.

Crystallinity was measured by X-ray diffraction at 26°C.

Melt flow rate (MFJqo, c): ASTMJ)
Measured under -E conditions (190°C, 2160g).

Example 1 Maleic anhydride modified ethylene/propylene/ENB copolymer (ethylene content 61 mol%, ENB content 2.6 mol%, MFR 1,85 g/iomin% anhydride 719
0℃ Leic acid content 0.5g/100g base, density 0.87
g/Cm6, crystallinity 14%) and polyethylene (1-butene content 1.9 mol%, MFR 1.5 g/l 0 m1n
% density 0.96190℃ g/C horn 13, crystallinity 76%) using a 33mmφ extruder (L/D=28.3Qm+
The mixture was premixed at 230° C.). Continuing,
This premix and nylon 6 (manufactured by Toshishiku Co., Ltd.), Amiran 1021XF, MFR 3,74g/10m1n, Q
Conditions] were mixed in the proportions shown in Table 1 to prepare a triblend consisting of two types of pellets. Zarani, 2
Single screw extrusion set at 60°C (L/D 28.3Qmm
φ) to prepare a melt blend (pellet form). The pellets were vacuum-dried at 100° C. for one day and night, and then injection molded under the following conditions to prepare specimen for measuring physical properties.

Cylinder temperature 260°C Injection pressure 650 kq / Cm2 Injection time
i Q sec Mold temperature 80'C Then 1. Physical properties were evaluated by the following method.

MFR measurement; ASTlvl D-! 238-79 Q
MFR was measured under the following conditions.

Bending test; using a 1/8" thick test piece, ASTIvl
Flexural modulus FM (kg/'C) by D-790-80
Id2), bending yield strength F S (1 (17/1J2)
was measured. The condition of the test piece was adjusted at 2°C at 150°C.
The test was carried out in a constant temperature and humidity room at %RH for 3 days.

Falling weight impact strength: By dropping a weight of a certain shape from a height of 90 (Jl) onto a test piece (diameter 5Qmmφ, thickness 1.2mm) placed horizontally at -60°C, and changing the weight of the weight, Falling weight impact strength was evaluated using the weight of the weight required to break 50% of a certain number of test pieces (ω).
Conditioning of the test piece was carried out for 6 days in a constant temperature and humidity room at 26° C. and 150% RH.

Izot impact strength: using a 1/8" thick test piece, A
-40°C notched isot impact strength was measured using STM D256. Conditioning of the test piece was at 23°C1
The test was carried out for 3 days in a constant temperature and humidity room at 50% RH.

Water absorption test: According to ASTIvl D570, test piece (
2 inches in diameter and 1/8 inch in thickness) at 100'C and 24
After intermittent drying, a water absorption test was conducted in 50'C water for 48 hours, and the water absorption rate was determined from the weight change rate of the test piece.

The results are shown in Table 1.

Examples 2 to 11, Comparative Examples 2 to 5 Same as Example 1 except that the modified ethylene/Q olefin/diene elastic copolymer and crystalline ethylene polymer shown in Table 1 were used in the proportions shown in Table 1. A blend was prepared using the method described above, and its physical properties were measured.

The results are shown in Table 1.

Claims (1)

[Claims] (1) A polyamide composition comprising a polyamide (A), a modified ethylene/α-olefin/diene elastic copolymer (B), and a crystalline ethylene polymer (Iυ), [1] Each of the components in the composition The composition of the components is such that the polyamide (
A) 100 weight W: parts of the modified ethylene Q-Ot
~Fin-diene elastic copolymer (B) from 1 to 100
Parts by weight of the crystalline ethylene polymer (0)
(!!) The modified ethylene/α-olefin/diene elastomeric copolymer (g) is in the range of 1 to 200% (!!) 0.01 to 10 units of unsaturated carboxylic acid or its derivative component per part by weight
It is obtained by graft copolymerization in a range of parts by weight, has a crystallinity of 40% or less, and has a melt flow rate at 190°C. FR19o, c] is in the range of 0.01 to 50 g/10 m1n, and (iii) the crystalline ethylene polymer (C) is one whose main component is an ethylene component unit;
Melt flow rate at 9o'c) (M”R190
A polyamide composition characterized in that 'C] is in the range of 0.01 to 5Qg/10m1n.