JPH0368902B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyamide resin composition that has excellent rigidity, low-temperature impact resistance, salt water resistance, and moldability. Polyamide resins are expected to be in great demand as engineering plastics due to their excellent physical properties. However, low temperature impact resistance, water resistance,
Performance such as salt water resistance is not sufficient, and improvements are desired. For example, as a method of improving impact resistance such as Izotsu impact strength,
Publication No. 12546, Japanese Patent Publication No. 1983-44108, Japanese Patent Publication No. 1983
Prior art documents such as JP-A-9661 and JP-A-55-9662 describe modified α-olefin systems such as ethylene/α-olefin copolymers, which are polyamide resins grafted with α,β-unsaturated carboxylic acids. A method of compounding an elastomeric polymer has been proposed. The compositions proposed in these prior art documents all have improved impact resistance such as Izot impact strength.
There is a drawback that the rigidity is greatly reduced, and the falling weight impact strength at low temperatures is also insufficient, resulting in a molded product having poor low-temperature impact resistance. Also,
These compositions often have excessively low melt fluidity and, depending on the molding method, also have the disadvantage of low molding processability. Furthermore, these compositions have poor water resistance, especially hydrolysis resistance, under conditions of contact with various alkali metal salts or alkaline earth metal salts, and are therefore not suitable for use in fields where such performance is required, particularly for automobiles. Its use in parts, etc. was also restricted. In addition, as a method to improve water resistance such as hygroscopicity or salt water resistance of polyamide resin,
53-80014, JP-A-56-167751, JP-A-56-109247, and JP-A-56-157451 disclose that polyamide resin contains ethylene as one component.
A method of blending a neutralized α,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 do not have the effect of improving impact resistance such as Izot impact strength, especially low-temperature impact resistance. It has the disadvantage of being inferior in some respects. Furthermore, as a method for improving the decrease in rigidity of the polyamide resin composition mentioned above, Japanese Patent Application Laid-Open No. 57-8246 discloses that crystalline polyolefin and low-crystalline ethylene.
A method of blending a graft modified composition with an α-olefin copolymer has been proposed. but,
In this method, it is difficult to control the melt fluidity of the modified polyolefin and modified low-crystalline ethylene/α-olefin copolymer in the graft modified product due to crosslinking, and as a result, a polyamide composition with good dispersibility cannot be obtained. The temperature range for improving impact resistance becomes significantly narrower, and the improvement effect is also small, especially at -20°C.
There are disadvantages in that the following low-temperature Izot impact strength and falling weight impact strength are significantly lowered, and the melt flowability of the composition is also lowered. Furthermore, in the prior art document, JP-A-55-
Publication No. 36279 describes the use of modified low-crystalline ethylene to improve the impact resistance of polyamide, as mentioned above.
When blending an α-olefin copolymer with an unmodified low-crystalline ethylene/α-olefin copolymer, a polyamide composition with excellent appearance and color tone can be obtained. It is also described that the use ratio of the crystalline ethylene/α-olefin copolymer can be reduced, so that it has excellent economic effects. However, according to the description of the publication, especially the description of Examples and Comparative Examples, it is clear that the modified low-crystalline ethylene/α-olefin copolymer blended into polyamide and the unmodified low-crystalline ethylene/α-olefin copolymer are blended into polyamide. Considering the effect of improving the impact resistance of polyamide compositions obtained by changing the composition with the olefin copolymer, unmodified low-crystalline ethylene/α-
An improvement in impact resistance was observed compared to the experiment in which the olefin copolymer was blended alone (Comparative Example 1), but the experiment in which the modified low-crystalline ethylene/α-olefin copolymer was blended alone (Reference Example) ), its impact resistance is higher than that of modified low-crystalline ethylene α-
The impact resistance is only improved in proportion to the blending ratio of the olefin copolymer, and economic effects are achieved by reducing the amount of the modified low-crystalline ethylene/α-olefin copolymer used. It's just that. As a result of studying the development of a polyamide composition with excellent performance, the present inventors discovered that a modified polar vinyl monomer-containing ethylene-based random copolymer and an α-olefin-based elastomeric polymer were mixed in a specific range. By blending the modified polar vinyl monomer-containing ethylene random copolymer with the α-olefin elastomeric polymer, it is possible to improve the impact resistance of the polyamide composition by blending it with polyamide to form a composition. It was discovered that there is a synergistic effect and that it is not just an effect of reducing the amount of the modified polar vinyl monomer-containing ethylene random copolymer used, and the present invention was achieved. According to the present invention, the polyamide composition of the present invention has improved impact resistance such as isot impact strength and falling weight impact strength at low temperatures, stress crack resistance, and water absorption and salt water decomposition resistance under salt water conditions. The water resistance of the composition has been significantly improved, and furthermore, this composition has excellent moldability because there is little decrease in melt flowability. To summarize the present invention, the present invention comprises polyamide
(A), a modified polar vinyl monomer-containing ethylene-based random copolymer (B), and an α-olefin-based elastic polymer (C), wherein the composition of each component in the composition is The modified polar vinyl monomer-containing ethylene random copolymer (B) is in the range of 1 to 100 parts by weight with respect to 100 parts by weight of the polyamide (A), and the α-olefin elastomer (C) is in the range of 1 to 100 parts by weight. [] The modified polar vinyl monomer-containing ethylene random copolymer (B) contains ethylene component units as a main component, and contains vinyl acetate and (meth)acrylic acid as polar vinyl monomers. 100% of a base polar vinyl monomer-containing ethylene random copolymer containing at least one component unit selected from the group consisting of esters, (meth)acrylic acid, and neutralized salt component units of (meth)acrylic acid.
It is obtained by graft copolymerizing an unsaturated carboxylic acid or its derivative component unit in the range of 0.01 to 10 parts by weight, and has a melt flow rate at 190°C [MFR190°C] of 0.01 to 10 parts by weight.
50 g/10 min, and [] the α-olefin elastomer (C) has a crystallinity of 40% or less;
The gist of the invention is a polyamide composition characterized by having a melt flow rate at 190°C [MFR190°C] in the range of 0.01 to 100g/10min. The polyamide (A) used in the polyamide composition of the present invention is of sufficient molecular weight to produce molded articles, and is composed of a saturated organic dicarboxylic acid having 4 to 12 carbon atoms and a saturated organic dicarboxylic acid having 2 to 13 carbon atoms. It can be produced by condensing equimolar amounts of organic diamines having 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, suberic acid, sebacic acid and dodecanedioic 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 azelamide (6.9 nylon), polyhexamethylene sebaamide (6.10 nylon) and polyhexamethylene dodecanoamide (6.12 nylon), There are polybis(4-aminocyclohexyl)methandodecanamides, or polyamides prepared by ring opening of lactams, namely polycaprolactam (6nylon), polylauritulactam or poly-11-aminoundecanoic acid. It is also possible to use polyamides produced by polymerization of at least two amines or acids used to produce the polyamides mentioned, for example polymers made from adipic acid and isophthalic acid and hexamethylene 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 azelamide (nylon 6.9) and polycaprolactam (nylon 6)
It is. The modified polar vinyl monomer-containing ethylene random copolymer (B) to be blended into the polyamide composition of the present invention has ethylene component units as a main component, and vinyl acetate as a polar vinyl monomer component unit,
Base containing at least one component unit selected from the group consisting of esters of (meth)acrylic acid, (meth)acrylic acid, and neutralized salt component units of (meth)acrylic acid.Polar vinyl monomer-containing ethylene-based random. 0.01 to 0.01 to 100 parts by weight of unsaturated carboxylic acid or its derivative component unit per 100 parts by weight of copolymer.
It is necessary that the base polar vinyl monomer is graft copolymerized in the range of 10 parts by weight, and that the melt flow rate at 190°C [MFRB 190°C] is in the range of 0.01 to 50 g/10 min. Ethylene-based random copolymer containing
It is obtained by graft copolymerizing 0.1 to 5 parts by weight of an unsaturated carboxylic acid or its derivative component unit to 100 parts by weight, and the melt flow rate at 190°C [MFRB 190°C] is 0.1 to 5 parts by weight.
Preferably, it is in the range of 20g/10min. When the grafting ratio of the unsaturated carboxylic acid or its derivative component unit in the modified polar vinyl monomer-containing ethylene random copolymer is less than 0.01 part by weight, the impact strength of the composition decreases because the compatibility with the polyamide decreases. However, if it exceeds 10 parts by weight, the water resistance and impact strength of the composition will decrease. The melt flow rate of the modified polar vinyl monomer-containing ethylene random copolymer is 0.01.
If it is less than 50 g/10 min, the impact strength and melt fluidity of the polyamide composition will decrease, and if it is more than 50 g/10 min, the impact resistance will decrease. The base ethylene random copolymer constituting the modified polar vinyl monomer-containing ethylene random copolymer (B) contains vinyl acetate component units, (meth)acrylic acid component units, (meth)acrylic acid component units, and (meth)acrylic acid component units as polar vinyl monomer component units. ester component unit of acrylic acid,
It is an ethylene-based random copolymer containing at least one component unit selected from the group consisting of neutralized salt component units of (meth)acrylic acid, and whose main component is an ethylene component unit, and whose temperature at 190°C is Melt flow rate is usually 0.01 to 50g/
10 min, more preferably in the range of 0.05 to 20 g/10 min. Further, the modified polar vinyl monomer-containing ethylene random copolymer (B) may contain carbon monoxide as another copolymerization component. When the base polar vinyl monomer-containing ethylene random copolymer is an ethylene random copolymer containing vinyl acetate component units, the content of the ethylene component units is usually 70 to 99.5 mol%, preferably 75%. The range is from 99% to 99% by mole,
The content of vinyl acetate component units in the ethylene/vinyl acetate random copolymer is usually in the range of 1 to 30 mol%, preferably 2 to 25 mol%.
Its crystallinity is usually 0 to 60%, preferably 0
to 50%, and its melting point is usually 105℃
The temperature is preferably below 100°C, and the density is usually 0.92 to 0.99g/cm ³ , preferably
It is in the range of 0.93 to 0.98 g/cm ³ . When the base polar vinyl monomer-containing ethylene random copolymer is an ethylene random copolymer containing (meth)acrylic acid or (meth)acrylic acid neutralized salt component units, the ethylene component units are The content is usually in the range of 70 to 99 mol%, preferably 80 to 98 mol%, (meth)
The content of neutralized salt component units of acrylic acid is usually 0.05
from 10 mol%, preferably from 0.1 to 8 mol%
within the range of The ethylene-based random copolymer containing neutralized salt component units of (meth)acrylic acid is usually prepared by [1] ethylene/(meth)acrylic acid random copolymer by neutralizing the (meth)acrylic acid component units. Method for converting (meth)acrylic acid into neutralized salt component units, [2] (meth)acrylic acid ester component units are converted into (meth)acrylic acid ester component units by hydrolysis of ethylene/(meth)acrylic acid ester random copolymer
A method of converting into acrylic acid component units and further neutralizing them to convert into neutralized salt component units of (meth)acrylic acid, or [3] Ethylene.
By any method of converting (meth)acrylic acid ester component units into (meth)acrylic acid neutral salt component units by directly saponifying a (meth)acrylic acid ester random copolymer. can be manufactured. In addition, the above [1],
In both methods [2] and [3], (meta)
Vinyl acetate may be contained as a vinyl monomer other than acrylic acid and its derivatives. Furthermore, carbon monoxide may be contained as a copolymerization component other than the vinyl monomer. (meta)
The ethylene random copolymer containing neutralized salt component units of acrylic acid contains, in addition to the essential components of the ethylene component unit or the neutralized salt component unit of (meth)acrylic acid, as is clear from the above production method. ) It may contain acrylic acid component units and/or (meth)acrylic acid ester component units and/or vinyl acetate component units. The content of the (meth)acrylic acid and/or (meth)acrylic acid ester component units is usually in the range of 0.1 to 15 mol%, preferably 0.5 to 10 mol%. The content of neutralized salt component units of (meth)acrylic acid in the ethylene-based random copolymer is within the above range, and the neutralization rate of (meth)acrylic acid component units is usually 5% or more, preferably It is in the range of 10 to 90%. Further, the content of vinyl acetate component units in the ethylene random copolymer is usually 1 to 30 mol%, preferably 2
The content ranges from 20% to 20% by mole. The crystallinity of the ethylene random copolymer containing neutralized salt component units of (meth)acrylic acid is usually 0 to 50.
%, preferably in the range of 0 to 40%, its melting point is usually below 105°C, preferably below 102°C, and its density is usually 0.92 to 0.97 g/
cm ³ , preferably in the range of 0.925 to 0.965 g/cm ³ . When the base polar vinyl monomer-containing ethylene random copolymer is an ethylene random copolymer containing neutralized salt component units of the (meth)acrylic acid, specifically, as the (meth)acrylic acid component units, It is an acrylic acid or methacrylic acid component unit, and a neutralization salt component unit of (meth)acrylic acid is specifically an ammonium salt or metal salt of acrylic acid or methacrylic acid. Examples of metal salts include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as magnesium salts, calcium salts, strontium salts, and barium salts, zinc salts, cadmium salts, and aluminum salts. is preferably an ammonium salt, an alkali metal salt, a magnesium salt or a zinc salt. In addition, (meth)acrylic acid ester components include (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate. Examples include acid alkyl esters. The unsaturated carboxylic acid or its derivative component unit of the graft monomer component constituting the modified polar vinyl monomer-containing ethylene random copolymer [B] includes, for example, acrylic acid, methacrylic acid, α-ethyl acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endocys-bicyclo[2.2.1]hept-5-ene-2,
3-dicarboxylic acid (nadic acid), methyl-endocys-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid (methyl nadic acid)
Examples include unsaturated dicarboxylic acids such as unsaturated dicarboxylic acids, and derivatives of unsaturated dicarboxylic acids such as acid halides, amides, imides, acid anhydrides, and esters of the unsaturated dicarboxylic acids, and specifically, maleyl chloride, maleimide,
Examples include maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and glycidyl maleate. Among these, unsaturated dicarboxylic acids or their acid anhydrides are preferred, and maleic acid, nadic acid, and their acid anhydrides are particularly preferred. To produce the modified polar vinyl monomer-containing ethylene-based random copolymer by graft copolymerizing a graft monomer selected from the unsaturated carboxylic acids or derivatives thereof onto the polar vinyl monomer-containing ethylene-based random copolymer, conventionally known methods can be used. Various methods can be adopted. For example, there is a method in which an ethylene-based random copolymer containing a polar vinyl monomer is melted and a graft monomer is added thereto to carry out graft copolymerization, or a method in which it is dissolved in a solvent and a graft monomer is added therein 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. The grafting reaction is usually carried out at a temperature of 60 to 350°C. The proportion of radical initiator used is ethylene random copolymer containing polar vinyl monomer.
It is usually in the range of 0.01 to 20 parts by weight per 100 parts by weight. Examples of the radical initiator include organic peroxides, organic peresters, and azo compounds. The α-olefin elastic polymer (C) to be blended into the polyamide composition of the present invention has α-olefin as its main component, has a crystallinity of 40% or less, and Melt flow rate at 190℃ [MFRC 190℃] is 0.01 to 50g
It is necessary that the crystallinity is in the range of 10/min, and furthermore, the crystallinity is in the range of 35% or less, and the melt flow rate [MFRC 190℃] is in the range of 0.02 to 30g/10min. preferable. Regarding other physical properties of the α-olefin elastic polymer, the glass transition temperature is usually in the range of -10°C or lower, preferably -20°C or lower. When the degree of crystallinity of the α-olefin elastomer polymer is higher than 40%, the effect of improving the impact resistance of the polyamide composition decreases. In addition, the melt flow rate of the α-olefin elastomer at 190°C is
When it is less than 0.01g/10min, the melt fluidity of the polyamide composition decreases, and when it is less than 50g/10min,
If the time is greater than 10 min, the impact resistance of the polyamide composition will decrease. Here, the α-olefin component units include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1
-Pentene, 1-hexene, 1-octene, 1-
Decene, 1-dodecene, 1-tetradecene, 1-
Examples include hexadecene and 1-octadecene. The α-olefin elastic polymer may be composed of two or more α-olefin components, and may also contain a small amount of other copolymerizable components in addition to these α-olefin component units. I can't help it. Components other than α-olefin that can be copolymerized include 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, dicyclopentadiene, and 5-ethylidene-2.
Examples include non-conjugated diene components such as -norbornene, 5-vinyl-2-norbornene, and 2,5-norbonadiene, and conjugated diene components such as butadiene, isoprene, and piperylene.
The content of α-olefin component units constituting the α-olefin elastic polymer is usually 85 mol% or more,
Preferably it is in the range of 90% or more. Examples of the α-olefin-based elastic polymer include ethylene/propylene copolymer, ethylene/1-butene copolymer, ethylene/4-methyl-1-pentene copolymer, ethylene/1-hexene copolymer, and ethylene.・1-
Octene copolymer, ethylene/1-decene copolymer, propylene/ethylene copolymer, propylene/1-butene copolymer, propylene/4-methyl-1-bentene copolymer, propylene/1-octene copolymer α of coalescence, propylene/1-decene copolymer, propylene/1-dodecene copolymer, etc.
-Olefin elastic copolymer, ethylene/propylene/1,4-hexadiene copolymer, ethylene/propylene/1,4-hexadiene copolymer,
Propylene/dicyclopentadiene copolymer, ethylene/propylene/ethylidenenorbornene copolymer, ethylene/propylene/norbonadiene copolymer, ethylene/propylene/2-ethylidene-5-norbornene/2-vinyl-5-norbornene copolymer Examples include α-olefin/non-conjugated diene elastic copolymers such as .
Among these α-olefin elastomeric polymers, α-olefin elastomers containing ethylene and/or propylene component units as main components are preferable, particularly ethylene/α-olefin elastomeric copolymers or propylene component units. - An α-olefin elastic copolymer is preferable. In the polyamide composition of the present invention, the modified vinyl monomer-containing ethylene random copolymer (B)
When blending the α-olefin elastomer (C) with polyamide (A), the ratio of the melt flow rates at 190°C [MFR190°C] of the two, [MFRB 190°C]/[MFRC 190°C] Values are typically adjusted to a range of 0.01 to 100, and further adjusted to a range of 0.02 to 50. In the polyamide composition of the present invention, the blending ratio of the modified polar vinyl monomer-containing ethylene random copolymer (B) to 100 parts by weight of the polyamide (A) must be in the range of 1 to 100 parts by weight. The amount is more preferably 2 to 80 parts by weight, particularly preferably 5 to 50 parts by weight. When the blending ratio of the ethylene random copolymer containing modified polar vinyl monomer exceeds 100 parts by weight, the rigidity and melt fluidity of the polyamide composition decrease, and when it decreases below 1 part by weight, the polyamide composition deteriorates. Impact resistance, stress crack resistance and water resistance become reduced. Further, the blending ratio of the α-olefin elastic polymer (C) to 100 parts by weight of the polyamide (A) needs to be in the range of 1 to 100 parts by weight, more preferably 2 to 80 parts by weight. , particularly preferably in the range from 5 to 50 parts by weight. The blending ratio of the α-olefin elastomer is 100
If the amount is more than 1 part by weight, the rigidity of the polyamide composition will decrease, and if it is less than 1 part by weight, the impact resistance, stress crack resistance and water resistance of the polyamide composition will decrease. Further, in the polyamide composition of the present invention, the blending ratio of the α-olefin elastic polymer (C) to 100 parts by weight of the modified polar vinyl monomer-containing ethylene random copolymer (B) is usually 5 to 2000 parts by weight. , preferably in the range of 10 to 1500 parts by weight. Furthermore, in the polyamide composition of the present invention, the unsaturated carboxylic acid graft-copolymerized with respect to the total amount of the modified polar vinyl monomer-containing ethylene random copolymer (B) and the α-olefin elastic polymer (C) or its derivative component unit is usually 0.02 to 7% by weight, preferably
It ranges from 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 antioxidants, ultraviolet absorbers, photoprotectants, phosphite stabilizers, peroxide decomposers, basic adjuvants, It is also possible to incorporate fillers such as nucleating agents, plasticizers, lubricants, antistatic agents, flame retardants, pigments, dyes, carbon black, asbestos, glass fibers, carrion, talc, silica, and silica alumina. Furthermore, other polymers can 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 other components, or the three essential components may be mixed with other remaining components that may be added as needed. 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 them, when producing the composition, (B) component and (C)
A composition obtained by melt-mixing the polyamide (A) component into a premix obtained by preliminary melt-mixing of the components has particularly excellent performance. The melt flowability [melt flow rate (MFR, 235°C, 1000g load)] of the composition of the present invention is usually 0.1
to 500g/10min, preferably 0.2 to 100
The range is g/10min. 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 the Examples and Comparative Examples, the degree of crystallinity and the melt flow rate at 190°C [MFR190°C] were measured by the following method. Crystallinity: Determined by X-ray diffraction at 23°C. Melt flow rate [MFR190℃]: ASTM D
Measured under -1238-79E conditions (190°C, 2160g). Example 1 Maleic anhydride-modified ethylene/isobutyl methacrylate tertiary random copolymer [methacrylic acid unit content 3.7 mol%, isobutyl methacrylate unit content 2.3 mol%, MFR 190°C 17
g/10 min, density 0.95 g/cm ³ , crystallinity 27%, melting point
84℃, maleic anhydride unit content 0.5g/100g - base copolymer] and ethylene-propylene elastic copolymer [ethylene content 80 mol%, MFR 190℃ 0.8g/
10 minutes, density 0.87 g/cm ³ , crystallinity 15%, glass transition point -60°C] were premixed at the ratio shown in Table 1 using a 30 mmφ extruder (L/D 28, set at 230°C). . Next, this premix and nylon 6 [manufactured by Toray Industries, Inc., Amilan CM1021XF, MFR 3.74 g/
10 min, Q condition] were mixed in the proportions shown in Table 1 to prepare a dry blend consisting of two types of pellets. Furthermore, the mixture was supplied to a single screw extruder (L/D28, 30 mmφ) set at 260°C to prepare a melt blend (pellet shape). the pellets
After vacuum drying at 100° C. for one day and night, injection molding was performed under the following conditions to produce specimen for measuring physical properties. Cylinder temperature: 260°C Injection pressure: 650Kg/cm ² Injection time: 10sec Mold temperature: 80°C Subsequently, physical properties were evaluated by the following method. MFR measurement: MFR under ASTM D-1238-79Q conditions
was measured. Bending test: ASTM D using a 1/8″ thick test piece
-790-80, the flexural modulus FM (Kg/cm ² ) and flexural yield strength FS (Kg/cm ² ) were measured. The test pieces were conditioned for 3 days in a constant temperature and humidity room at 23°C and 50% RH. Falling weight impact strength: A weight of a certain shape is dropped from a height of 90cm onto a test piece (diameter 50mmφ, thickness 1.2mm) placed horizontally at -60℃, and a certain number of pieces are tested by varying the weight of the weight. Falling weight impact strength was evaluated based on the weight (g) of weight required for 50% of the pieces to break. The condition of the test piece was adjusted at 23
The test was carried out for 3 days in a constant temperature and humidity room at 50% RH. Izotsu impact strength: using a 1/8″ thick test piece,
-40°C notched isot impact strength was measured according to ASTM D-256. Conditioning the specimen
The test was carried out for 3 days in a constant temperature and humidity room at 23℃ and 50%RH. Water absorption test: According to ASTM D-570, a test piece (2 inches in diameter, 1/8 inch in thickness) was dried at 100°C for 24 hours, then subjected to a water absorption test in water at 50°C for 48 hours, and water absorption was determined from the weight change rate of the test piece. The rate (%) was calculated. The results are shown in Table 1. Examples 2 to 14 and Comparative Examples 1 to 5 The modified polar vinyl monomer-containing ethylene random copolymer (B) shown in Table 1 and the olefin-based elastic polymer (C) were used in the proportions shown in Table 1. A blend was prepared in the same manner as in Example 1, and its physical properties were measured. The results are shown in Table 1.

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Claims (1)

[Scope of Claims] 1. A composition comprising a polyamide (A), a modified polar vinyl monomer-containing ethylene random copolymer (B), and an α-olefin elastomer (C), comprising: [] The composition The composition of each component is in the range of 1 to 100 parts by weight of the modified polar vinyl monomer-containing ethylene random copolymer (B) to 100 parts by weight of the polyamide (A); The elastic polymer (C) is in the range of 1 to 100 parts by weight, [] The modified polar vinyl monomer-containing ethylene random copolymer (B) has ethylene component units as a main component, and contains ethylene units as the polar vinyl monomer. Contains a base polar vinyl monomer containing at least one component unit selected from the group consisting of vinyl acetate, esters of (meth)acrylic acid, (meth)acrylic acid, and neutralized salt component units of (meth)acrylic acid. 100% of ethylene random copolymer
Graft copolymerized with unsaturated carboxylic acid or its derivative component units in the range of 0.01 to 10 parts by weight, and has a melt flow rate at 190°C [MFR190°C] of 1 to 50
g/10 min, and [] the α-olefin elastomer (C) has a crystallinity of 40% or less, and
A polyamide composition characterized by having a melt flow rate at 190°C [MFR190°C] in the range of 0.01 to 100g/10min.