JPS63191857A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. having high impact resistance and good modulus, by blending a polyamide with a multi-component olefin polymer and a modified product obtd. by the treatment with an unsaturated carboxylic acid in the presence of a radical initiator. CONSTITUTION:A resin compsn. consists of a polyamide resin and the following modified olefin polymer in such a proportion that the amount of the polyamide resin accounts for 50-95wt.% of the total amount of the compsn. In said modified olefin polymer, a copolymer (a) of ethylene with a 3C or higher alpha-olefin and 1-99wt.% multi-component olefin polymer (b) composed of 0.1-50wt.% at least one alpha,beta-ethylenically unsaturated carboxylic ester among alkyl (meth) acrylates and 0.05-20wt.% dibasic unsaturated carboxylic acid or derivative are used as starting polymers. These polymers are treated with an unsaturated carboxylic acid or its derivative in the presence of a radical initiator, using the resulting modified product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyamide resin composition having extremely excellent impact resistance. More specifically, the present invention relates to a polyamide resin composition composed of a polyamide resin and a specific modified olefin polymer, and the object is to provide a polyamide resin composition that has extremely excellent impact resistance and a good modulus of elasticity. That is.

Due to its excellent physical and chemical properties, polyamide resin is widely used in various fields such as synthetic fibers, films, and various molding materials. In particular, in recent years, polyamide resin has been widely used as an engineering plastic in various electronic/electrical parts, automobile parts, mechanical parts, etc. by taking advantage of its properties such as wear resistance, heat resistance, mechanical properties, and electrical properties. It has become so.

However, although polyamide resins have the above-mentioned good properties, they are inferior in impact resistance, especially when used as molded parts, and many methods have been proposed to improve these properties.

That is, a composition in which a polyamide resin is blended with an acrylic ester or methacrylic ester copolymer of an olefin and a tertiary alcohol (Japanese Patent Publication No. 4G-28791)
), compositions containing modified polyolefins grafted with unsaturated polyhydric carboxylic acid or its derivatives (JP-A-50-99442, JP-A-52-151348, JP-A-55-9681, JP-A-55-! 3B82, 55-1
No. 85952, No. 57-8299, No. 57-7845
No. 3 and No. 57-200948 and U.S. Patent No. 3,484,403, etc.), a copolymer of ethylene and an unsaturated carboxylic acid alkyl ester, an unsaturated carboxylic acid or its metal salt, an unsaturated epoxide, etc. (JP-A No. 51-70254, No. 51-1013)
No. 157, No. 51-125'451, pl? 15
No. 1-143081, No. 52-47051%, No. 52
-80352, etc.) and compositions containing ethylene, α-olefin copolymers, and ethylene ionomer resins (JP-A-58-23850, JP-A-58-29).
No. 954, etc.), the impact resistance, which is the drawback mentioned above, has been improved and is generally called impact resistant nylon, and some of these compositions are in practical use.

However, these impact-resistant nylons have recently been used under more severe conditions, creating a need for materials with even better performance in terms of impact resistance, as well as improved elasticity. It is also required to be good in terms of efficiency.

Incidentally, ethylene-α-olefin copolymers grafted with maleic anhydride as an unsaturated carboxylic acid derivative have a remarkable effect in improving the impact resistance of polyamide resins, but on the other hand, the elastic modulus It is generally well known that the mechanical strength of steels, etc., is greatly reduced, and the performance is not necessarily satisfactory.

As a result, the market as a molding material is sometimes limited, and there is a demand for polyamides that have higher impact resistance and better elastic modulus.

~ Gashi − ・
Based on the above, the present invention provides a composition that has better impact resistance than the above-mentioned compositions and has a good elastic modulus without impairing the excellent properties inherent to polyamide resin. It's about getting things.

According to the present invention, these problems are solved by a composition comprising a polyamide resin and a modified olefin polymer,
The composition ratio of the polyamide resin in the total amount of these is 50 to 95% by weight (that is, the composition ratio of the modified olefin polymer is 50 to 5% by weight), and as a starting polymer for the modified olefin polymer. From the group consisting of (a) a copolymer of ethylene and an α-olefin having 3 or more carbon atoms (hereinafter referred to as "ethylene copolymer") and (b) an acrylic acid alkyl ester and a methacrylic acid alkyl ester At least one selected α, β
- An olefin-based multicomponent copolymer containing 0.1 to 50% by weight of an ethylenically unsaturated carboxylic acid ester and 0.05 to 20% by weight of a dibasic unsaturated carboxylic acid or its derivative as one monomer unit; The proportion of the olefinic multi-component copolymer in the polymer is 1 to 99% by weight, and the modified polymer is produced by treating these polymers with an unsaturated carboxylic acid or a derivative thereof in the presence of a radical initiator. The problem can be solved by a polyamide resin composition characterized by using a polyamide resin composition. The present invention will be explained in detail below.

(A) Polyamide resin The polyamide resin used in the present invention is a linear polymer compound having an acid amide bond (-C0NH-),
BACKGROUND ART Generally speaking, polyamides obtained by polycondensing dibasic acids and diamines and polyamides obtained by self-polycondensing cyclic lactamya amino acids are known. Typical examples of the former include polycondensates of hexamethylene and adipic acid (nylon ee), polycondensates of hexamethylene diamine and sebacic acid (nylon 6-10), and polycondensates of hexamethylene diamine and dodecanoic acid. Polycondensate (nylon El-12), polycondensate of hexamethylene diamine and terephthalic acid (nylon 6)
T), polycondensate of xylene diamine and adipic acid (X
D-8 nylon) and a polycondensate of xylene diamine and cepatic acid (XD-10 nylon). Representative examples of the latter include a self-polycondensate of caprolactam (nylon 8), lo-aminoundecane, Examples include self-polycondensates of acids (nylon 11) and self-polycondensates of lauryl lactam (nylon 12). Furthermore, the degree of polymerization of polycondensates and mixed polyamide resins containing these as main constituents is particularly limited. However, the relative viscosity is generally between 2.0 and 5.6, particularly between 2.5 and 5.6.
4.5 is preferred. These polyamide resins are manufactured industrially and are used in a wide variety of fields, and their manufacturing methods, types, various physical properties, molding methods, etc. are described in Shunsuke Muratachibana, Ryohei Oda, "Publastic Handbook" edited by Minoru Imoto (Breakfast Shoten, published in 1980), No. 521
This is well known from pages 548 to 548.

(B) Modified olefin polymer The modified olefin polymer used in the present invention includes the ethylene copolymer described below, α, β-ethylenically unsaturated carboxylic acid ester, and dibasic unsaturated carboxylic acid or It is produced by treating an olefin-based multicomponent copolymer containing the derivative as one monomer unit with an unsaturated carboxylic acid or its derivative in the presence of a radical initiator.

(1) Ethylene copolymer The ethylene copolymer used in the production of the modified olefin copolymer of the present invention is a copolymer of ethylene and an α-olefin having 3 or more carbon atoms, such as A Ziegler-Natsuta catalyst, especially a catalyst consisting of a vanadium compound such as vanadium oxytrichloride or vanadium tetrachloride, and an organoaluminum compound, is used, and ethylene is 50% or more and α-olefin is 50% or less, preferably ethylene. 75-95% and α-olefin 25-5%
Obtained by copolymerization. Further, a multi-component copolymer obtained by further copolymerizing a third component described below at a molar ratio of ethylene and α-olefin of 5% or less can also be used.

The number of carbon atoms in α-olefin is usually 12 or less, and typical examples include propylene, butene-1, hexene-1
, decene-1 and 4-methylpentene-1, among which propylene and butene-1 are preferred, and as the third component, 1,4-pentadiene, 1
．． Linear or branched diolefins containing two double bonds at the end, such as 5-hexadiene and 3,3-dimethyl-1,5-hexadiene, 1,4-hexadiene and 6-methyl-1 , 5-hebutadiene, linear or branched diolefins containing only one terminal double bond, or bicyclo(2,2,1)-hebutene-2
(norbornene) and its derivatives (eg, ethylidenenorbornene, methylenenorbornene, vinylnorbornene) and other cyclic diene hydrocarbons having a double bond.

The melt flow index of this ethylene copolymer (
Measured under conditions 4 according to JIS K7210, hereinafter referred to as MFRJ) is usually 0.005 to 10.0 g
/10 minutes and 0. O1 to 5.0 g/10 min is desirable, and 0.05 to 5.0 g/10 min is particularly preferred.

(2) Olefin-based multi-component copolymer The olefin-based multi-component copolymer used to produce the modified olefin-based polymer of the present invention is selected from the group consisting of acrylic acid alkyl ester and methacrylic acid alkyl ester. It is an olefin-based multi-component copolymer containing at least one α,β-type ethylenically unsaturated carboxylic acid ester and a dibasic unsaturated carboxylic acid or a derivative thereof as a monomer unit.

The number of carbon atoms in the alkyl group of the α, β-ethylenically unsaturated carboxylic acid ester is usually 1 to 10 (preferably 1 to 8).
Among these α,β-type ethylenically unsaturated carboxylic acid esters, representative examples of alkyl acrylates include methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. It will be done. Furthermore, representative examples of alkyl methacrylates include methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

Among these α,β-ethylenically unsaturated carboxylic acid esters, methyl acrylate, ethyl acrylate, butyl acrylate, and methyl methacrylate are particularly preferred. Further, among dibasic unsaturated carboxylic acids or derivatives thereof, the dibasic unsaturated carboxylic acid usually has at most 40 carbon atoms, preferably 35 or less. Typical examples include maleic acid, itaconic acid, 3,6-endomethylene-1,2,
Mention may be made of 3,8-tetrahydro-cis-phthalic acid (nadic acid) and fumaric acid. Typical examples of derivatives of dibasic unsaturated carboxylic acids include acid anhydrides, esters, amide compounds of the dibasic unsaturated acids, and their metals (metals include usually alkali metals and those listed in IA of the Periodic Table). and Group IB metals, such as sodium, magnesium, calcium, zinc) salts. Preferred examples of these dibasic unsaturated carboxylic acids and derivatives thereof include maleic acid, maleic anhydride,
Mention may be made of nadic acid and nadic anhydride.

Furthermore, the number of carbon atoms in the olefin is generally at most 12, and preferably 8 or less. Representative examples of desirable olefins include ethylene, propylene and butene-1, with ethylene being most preferred.

The copolymerization ratio of olefin in this multi-component copolymer is 30 to 9
9.85% by weight, particularly preferably 40 to 99.5% by weight, and the copolymerization ratio of α,β-ethylenically unsaturated galponic acid ester is 0.1 to 50% by weight, especially 1. 0 to 50% by weight is desirable. Furthermore, the copolymerization ratio of the dibasic unsaturated carboxylic acid or its derivative is 0.05 to 20% by weight as a total amount thereof, particularly 0.05% to 20% by weight.
．． α in this multi-component copolymer is preferably 5 to 10% by weight.
If the copolymerization ratio of β-ethylenically unsaturated carboxylic acid ester and dibasic unsaturated carboxylic acid or its derivative is less than the lower limit, the impact resistance of the resulting composition will not necessarily be satisfactory; If it exceeds this, the softening point of this multi-component copolymer will increase, fluidity will decrease, and it will not only be difficult to modify (process) unsaturated carboxylic acids or their derivatives as described below, but also economically. I also don't like it.

The MFR of this multi-component copolymer is usually 0.01 to 100g7
For 10 minutes, 0.05 to 100 g/710 minutes is desirable, and particularly 0.1 to 50 g/10 minutes is preferred.

If a multicomponent copolymer with an MFR of less than 0.01 g 710 min is used, processability is poor;
If it exceeds 10 minutes, the moldability will be poor.

This multi-component copolymer is produced using the generally well-known radical high-pressure polymerization method, for example, by polymerizing each monomer under high pressure (generally,
500 to 2,500 Kg/cm') and high temperature (usually 120 to 260°C) using a chain transfer agent if necessary, it can be easily produced by a radical polymerization method.

(3) Unsaturated carboxylic acids or derivatives thereof The unsaturated carboxylic acids or derivatives thereof used to treat (modify) the mixture of the ethylene copolymer and the olefin multi-component copolymer are monobasic unsaturated carboxylic acids or derivatives thereof. Mention may be made of carboxylic acids and the aforementioned dibasic unsaturated carboxylic acids, as well as metal salts, amides, imides, esters and anhydrides of these unsaturated carboxylic acids. Among these, the basic unsaturated carboxylic acid usually has at most 30 carbon atoms, especially 2 carbon atoms.
Representative examples of basic unsaturated carboxylic acids, preferably 5 or less, include acrylic acid, methacrylic acid, and crotonic acid. Typical examples of dibasic unsaturated carboxylic acids and their derivatives include maleic acid, fumaric acid, itaconic acid, and sudic acid as dibasic unsaturated carboxylic acids, and maleic anhydride, nadic acid anhydride as their anhydrides. monoethyl or diethyl maleate and glycidyl methacrylate as its esters, and maleimide as its imide. Among these unsaturated carboxylic acids or derivatives thereof, anhydrides of dibasic unsaturated carboxylic acids are preferred.

(4) Radical initiator Furthermore, the decomposition temperature of the radical initiator used for producing the modified olefin polymer of the present invention with a half-life of 1 minute is usually 100°C or higher, and those of 105°C or higher are Preferably, temperatures of 120°C or higher are particularly suitable. Representative examples of suitable radical initiators include diwalnut peroxide, benzoyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butyl-peroxy)hexane. , 2,5-dimethyl-2,5-di(tertiary-butylperoxy)hexane-3, lauroyl peroxide, and tertiary-butylperoxybenzoate. .

(5) Usage ratio The proportion of the olefin-based multi-component copolymer in the total amount of the ethylene-based copolymer and the olefin-based multi-component copolymer is 1 to 89% by weight, preferably 5 to 95% by weight,
Particularly suitable is 10 to 90% by weight. If the proportion of the olefin-based multi-component copolymer in the total amount of the ethylene-based copolymer and the olefin-based multi-component copolymer is less than 1% by weight, it is difficult to obtain a uniform composition, and the elastic modulus may be affected. But it's not enough. On the other hand, if it exceeds 89% by weight, the impact resistance cannot be said to be satisfactory.

The ratio of the unsaturated carboxylic acid and its derivatives and the radical initiator to the total amount of 100 parts by weight of the ethylene copolymer and olefin multi-component copolymer is usually as follows.

For unsaturated carboxylic acids and derivatives thereof, the total amount thereof is 0.01 to 5.0 parts by weight, and 0.05 to 3 parts by weight.
．． 0 parts by weight is preferred, and 0.1 to 2.0 parts by weight is particularly preferred. If the total amount of unsaturated carboxylic acids and their derivatives used is less than 0.01 part by weight, the adhesiveness of the resulting modified olefin polymer will be insufficient. On the other hand, if the amount exceeds 5.0 parts by weight, there is a risk that decomposition or crosslinking reactions may occur during production of the modified olefin polymer.

Further, in the case of a radical initiator, the amount is 0.001 to 1.0 parts by weight, preferably 0,00 to 1.0 parts by weight, particularly 0.005 to 0.5 parts by weight. When the proportion of the radical initiator used is less than 0.005 parts by weight, the modification effect is not sufficiently exhibited, not only does it take a long time to complete the modification, but also unreacted substances are mixed. On the other hand, 1.
If it exceeds 0 parts by weight, excessive decomposition or crosslinking reaction may occur, which is undesirable.

(6) Production of modified olefin polymer The modified olefin polymer of the present invention can be produced by known means for producing this type of modified olefin polymer.

A typical production method involves preparing the ethylene copolymer, olefin multicomponent copolymer, and unsaturated copolymer in a solvent such as an aromatic hydrocarbon compound such as xylene or toluene, or an aliphatic hydrocarbon compound such as hexane or heptane. A method for producing a carboxylic acid or its derivative and a radical initiator by heating and mixing, and an ethylene copolymer thereof,
An olefinic multi-component copolymer, an unsaturated carboxylic acid or its derivative, and a radical initiator are mixed in advance under essentially non-reactive conditions, and the resulting mixture is processed into synthetic resins using a screw extruder, Banbury mixer, kneader, etc. One example is a manufacturing method by melt-mixing using a kneader used in the field of 1, but the latter method is preferred from the viewpoint of operation method and economical efficiency.

In the latter case, the temperature conditions for modification are appropriately selected taking into consideration the deterioration of the olefin multi-component copolymer, the decomposition of the unsaturated carboxylic acid or its derivative, the decomposition temperature of the organic peroxide, etc. is 100-350°C, preferably 150-350°C, especially 150-350°C
300°C is preferred.

(C) Composition ratio The composition ratio of the polyamide resin in the composition of the present invention is 50 to 95% by weight (that is, the composition ratio of the modified olefin polymer is 50 to 5% by weight), and 5 to 45% by weight.
If the composition ratio of the polyamide resin in the composition is less than 50% by weight, the mechanical strength of the resulting composition will be significantly reduced.On the other hand, If it exceeds 95% by weight, the effect of improving impact resistance will be poor.

(D) Production of composition In producing the composition of the present invention, methods generally used in the field of synthetic resins may be employed; mixing methods include Henschel mixer and tumbler.
A method of kneading a tri-blended resin mixture using a mixer such as a screw extruder, a kneader, and a mixer such as a Banbury mixer in a molten state, or a method in which each of the resins is quantitatively mixed instead of tri-blending. There is a method of kneading in a molten state while feeding it to the above-mentioned mixer using a feeder. Note that a more uniform composition can be obtained by carrying out these mixing methods two or more times as necessary.

In producing the composition of the present invention, stabilizers against oxygen, heat and light (ultraviolet light), flame retardants, lubricants, various fillers, reinforcing agents, antistatic agents, plasticizers and colorants (pigments) are used. Various additives may be added.

When this composition is melt mixed and molded as described below, the polyamide resin and modified olefin polymer to be blended will melt, but the process must be carried out within a temperature range where these will not deteriorate due to heat. is 150 to 350°C, preferably 180 to 300°C.

The composition of the present invention can be manufactured into molded articles having various shapes by molding methods such as extrusion molding, injection molding, and press molding that are commonly practiced in the field of thermoplastic resins.

- Hereinafter, the present invention will be explained in more detail with reference to Examples.

In addition, in the Examples and Comparative Examples, the Izod impact strength is 1/2×1 according to ASTM D-838.
/2 x 2.5 inch specimens were notched and measured at temperatures of 23°C and -30°C. In addition, the bending elastic modulus is 174 inches x 174 inches according to ASTM D-790.
Measurements were made on 1/2 inch by 5 inch rectangular specimens.

[(A) Production of modified olefin polymer] As the ethylene copolymer, an ethylene-propylene copolymer having an MFR of 0.45 g 710 minutes and a propylene copolymerization ratio of 25% by weight [hereinafter referred to as "copolymer"] Polymer (a)] and an ethylene-butene-1 copolymer having an MFR of 3.3 g/10 min and a butene-1 copolymerization ratio of 18% by weight [hereinafter referred to as "copolymer (b)”
Also, as an olefin-based multi-component copolymer, MFR is 1
．． 8 g/10 min of ethylene-methyl methacrylate-maleic anhydride ternary copolymer [copolymerization ratio S of methyl methacrylate, weight%, copolymerization ratio of maleic anhydride 2.8% by weight, hereinafter referred to as "polymer ( 1)] and an ethylene-ethyl acrylate-maleic anhydride ternary copolymer with an MFR of 5.5 g/10 minutes [copolymerization ratio of ethyl acrylate: 7.2% by weight, copolymerization ratio of maleic anhydride] 2.1% by weight, hereinafter referred to as "Polymer (2)"] were mixed in advance with the mixtures shown in Table 1. For 100 parts by weight of each mixture obtained, 0
．． 4 parts by weight of maleic anhydride and 0.012 parts by weight of 2,5-dimethyl-2,5-di(tertiary-butyl-peroxy)hexane were triblended for 5 minutes using a Henschel mixer. Each of the obtained mixtures was supplied to a non-vent type extruder (diameter: 40 cm) and melt-kneaded while melting at a temperature of 220°C to obtain various modified olefin polymers (abbreviations shown in Table 1). Maleic anhydride (MAR) reacted in the obtained modified olefin polymer.
) and MFR are shown in Table 1.

The weight of the reacted MA) was measured using an infrared spectroscopy method in a conventional manner.

[(B) Polyamide resin]

As a polyamide resin, a polycondensate of hexamethylene diamine and adipic acid having a relative viscosity [ηr] of 2.8 (
Nylon 6-6) was used.

(Left below) Examples 1 to 10, Comparative Examples 1 to 4 25 parts by weight of the modified olefin polymer shown in Table 1 and 75 parts by weight of nylon obtained as described above
8-6 was triblended for 5 minutes using a Henschel mixer. Each mixture obtained was processed using a twin-screw extruder (diameter
Pellets (composition) were produced using a 30+am) melt-kneading method at a temperature of 270°C.

Test pieces for performance evaluation were prepared from each composition obtained in this way using an injection molding machine, and the Izot impact strength (2
3°C (1-30°C) and flexural modulus were measured. The results are shown in Table 2.

(Left below) Brother J and Team Mei The modified olefin polymer used in the polyamide resin composition of the present invention is a conventional rubber (for example, a copolymer rubber containing ethylene and propylene as main components).

Not only can it be produced relatively easily and economically more advantageously than those grafted to However, it has excellent impact resistance. moreover,
Rigidity (flexural modulus) is also good. Therefore, the polyamide resin composition of the present invention can be used for automobile parts, electrical equipment parts,
It is clear that the company has a promising future in the field of electronic equipment and other industrial parts.

Claims (1)

[Claims] A composition consisting of a polyamide resin and a modified olefin polymer, in which the composition ratio of the polyamide resin in the total amount is 50 to 95% by weight, and (a) as a starting polymer for the modified olefin polymer. A copolymer of ethylene and an α-olefin having 3 or more carbon atoms; and (b) at least one α, β-ethylenically unsaturated carboxyl selected from the group consisting of alkyl acrylates and alkyl methacrylates. It is an olefin-based multi-component copolymer containing 0.1 to 50% by weight of an acid ester and 0.05 to 20% by weight of a dibasic unsaturated carboxylic acid or its derivative as a monomer unit, and the olefin in these polymers The ratio of multi-component copolymer is 1~
99% by weight, and is characterized by using a modified product produced by treating these polymers with an unsaturated carboxylic acid or a derivative thereof in the presence of a radical initiator.