JP3086493B2 - Polyamide resin composition with excellent impact resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin composition having excellent impact resistance.
The present invention relates to a polyamide resin composition comprising an acrylic random copolymer obtained by copolymerizing an ABS resin, a polyamide resin, and maleic anhydride, and having excellent impact resistance.

[0002]

2. Description of the Related Art A resin composition comprising an ABS resin and a polyamide resin is known. Particularly, a blend of an ABS resin and a polyamide resin is a disadvantage of each component resin.
Improves chemical resistance and dimensional stability of molded products. However, a blend composition comprising these two components is poor in compatibility (compatibility) between resins when simply blended, and is not suitable for practical use because a molded article is so-called delaminated. Therefore, attempts have been made to improve the performance by adding a compatibilizer to this blend system, and for example, Japanese Patent Application Laid-Open No. 62-164,760 corresponds to this. In this example, a graft polymer obtained by radical copolymerization of a styrene macromonomer, styrene and maleic anhydride was added to a polymer blend system of polyamide and polystyrene, and as a result, a system without the graft polymer was added. In comparison, it shows that tensile strength, elongation and impact resistance were all improved. In this example, however, the Izod impact strength of a simple blend of polyamide and polystyrene of 2.1 kg · cm / cm, whereas the Izod impact strength of a system to which 3 parts of a graft polymer as a compatibilizer was added was 4.3 kg · max. cm / cm, and such a composition cannot be said to be sufficient as a material resin for an automobile exterior or a power tool.

On the other hand, Japanese Patent Application Laid-Open No. 62-57,452 discloses a rubber graft resin such as ABS and a polyamide resin such as nylon-6, an acrylic elastomer and an acid-containing polymer such as styrene-acrylonitrile-maleic anhydride terpolymer. The composition having the above composition was obtained, and the improvement ratio of the impact resistance was examined. In this example, it has been found that the copolymerization ratio of maleic anhydride, particularly in the acid-containing polymer, greatly affects the impact resistance of the final composition. In this example, a modified composition comprising an acrylic elastomer added to a blend of ABS, a polyamide and an acid-containing polymer improves the impact resistance by about 8 times. However, in this example, there is no description of the heat resistance and the molding shrinkage of the obtained composition, and it cannot be said that the practicality for the above-mentioned application is still sufficient.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a method for obtaining a resin composition comprising an ABS resin and a polyamide resin.
An object of the present invention is to obtain a resin composition which has higher impact resistance than conventional ones, does not cause delamination during cutting or thin-piece molding, and is useful as a material for automobile exteriors or as a power tool material.

[0005]

That is, the present invention provides:
1) a) 50 to 80% by weight of an aromatic vinyl monomer and 10 to 70% by weight of a rubbery polymer,
40% by weight and a vinyl monomer copolymerizable therewith
20-80 parts by weight of a graft copolymer obtained by grafting 30-90 parts by weight of a monomer mixture consisting of 20% by weight and b) 0.010 to 0.100 mmol /
A resin composition comprising a polyamide resin having a relative viscosity and η _rel of 2.0 to 7.0 at 25 ° C. and a solution dissolved in 96% sulfuric acid at a concentration of 1 g / dl and 80 to 20 parts by weight. C) 60 to 98% by weight of methacrylic acid ester monomer [A], 1 to 25% by weight of aromatic vinyl monomer [B], and maleic anhydride [C] 1 to 1 part by weight, based on 100 parts by weight.
Acrylic random copolymer of 2 to 30% by weight
An object of the present invention is to provide a polyamide resin composition which is excellent in impact resistance by adding parts by weight. Hereinafter, the polyamide resin composition of the present invention will be described in more detail.

(Structure of the Invention) a. Graft copolymer (hereinafter referred to as ABS resin) The ABS resin used in the present invention is a polybutadiene rubbery polymer, an aromatic vinyl monomer represented by styrene, and a vinyl cyanide represented by acrylonitrile. Monomer and, if necessary, resin obtained by graft-copolymerizing other vinyl monomers copolymerizable with these monomers, such as emulsified / lumped suspension or continuous It may be manufactured by any polymerization method.

As the pobutadiene rubber mentioned here,
Examples thereof include polybutadiene, styrene-butadiene copolymer rubber, and butadiene-acrylonitrile copolymer rubber.

[0008] As the aromatic vinyl monomer, styrene,
Examples thereof include α-methylstyrene and p-methylstyrene, and these can be used in combination.

Examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile.

Examples of the vinyl monomer copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer include methyl acrylate, methyl methacrylate, and butyl acrylate.

[0011] The ratio of the components in the ABS resin is such that the rubber-like polymer mainly forms a hard resin, ie, a hard resin,
It is desirable that the amount be in the range of 10 to 70 parts by weight based on 30 to 90 parts by weight of the resin phase containing (aromatic vinyl monomer / vinyl cyanide monomer) as a main component. As for the matrix hard resin phase, the aromatic vinyl monomer accounts for 50% of the total.
The vinyl cyanide monomer is contained in an amount of 20 to 85% by weight.
It is preferable that the content of the vinyl monomer is 40% by weight or less and the other vinyl monomer copolymerizable therewith is 20% by weight or less.

When the content of the rubbery polymer is less than 10 parts by weight, the impact resistance of the final blend composition becomes poor, and
When the amount is more than 70 parts by weight, the heat resistance of the final composition does not increase.

On the other hand, the composition of the aromatic vinyl monomer in the matrix hard resin phase is 50% in order to improve moldability.
% By weight or more, and preferably 80% by weight or less in order to improve the affinity with the polyamide resin. If the amount of the vinyl cyanide monomer is at most 20% by weight, the chemical resistance of the final composition will be poor, and if it is at least 40% by weight, the compatibility with the polyamide will be poor. Incidentally, it is desirable that the proportion of the other vinyl monomer used as required does not exceed 20% by weight in order to exert the effects of the present invention.

B. Polyamide Resin The polyamide resin used in the present invention means a polymer formed by a condensation reaction of a diamine and a dibasic acid and a self-condensation reaction of an amino acid, and is generally known as "nylon".

The polyamides useful in the present invention have amide linkages, ie. It has a -CO-NH- bond in the main chain. Specifically, polyhexamethylene adipamide (nylon-6,
6), polyε-caprolactam (nylon-6), polyundecanolactam (nylon-11), polydodecanolactam (nylon-12) and copolymers thereof can be used. Among them, poly ε-caprolactam (nylon-6) and polyhexamethylene adipamide (nylon-6,6) are preferably used, and nylon-6 and nylon-6,6 are more preferably used. However, such a polyamide resin has an amino terminal group content of 0.010 mmol.
/ G to 0.100 mmol / g. This amount can be quantified by ¹ H-NMR or titration, but if the amino terminal group content is less than 0.010 mmol / g, the reactivity with the acrylic random copolymer is poor, so that a composition having good compatibility can be obtained. The physical properties of the final composition are low because they are not given. On the other hand, when the amino terminal group content is 0.10
If it exceeds 0 mmol / g, the moldability, melt fluidity and thermal decomposability of the final composition are poor.

The relative viscosity (η) of the polyamide used
_rel. (Measured at 25 ° C. using 96% sulfuric acid)
It is preferable to use those having a range of from 7.0 to 7.0. η
_{When rel} is 2.0 or less, the molecular weight is too low to give a practical composition, and when _rel is 7.0 or more, the melt fluidity of the final composition becomes low.

As the above-mentioned polyamide, those manufactured by a well-known manufacturing method are used. Usually, it can be produced by equimolar polycondensation reaction of diamine and dicarboxylic acid, self-condensation reaction of aminocarboxylic acid, or ring-opening polymerization of lactam.
An example of such a resin is Unitika's A103.
0BRL, A1030BRT (both nylon-6), A
100 (nylon-6, 6) and the like correspond to this.

<Acrylic random copolymer> The acrylic random copolymer used in the present invention is as follows. That is, the methacrylate monomer [A] 60
It is an acrylic tertiary random copolymer capable of co-polymerizing 〜98% by weight, aromatic vinyl monomer [B] 1-25% by weight, and maleic anhydride [C] 1-15% by weight.
Either methyl ester or ethyl ester is selected as the ester substituent of the methacrylate monomer [A], and methyl ester is more preferable. Even if an alkyl ester other than the above is selected, an alloy having high impact resistance, which is the object of the present invention, cannot be obtained.

The monomer [B] includes styrene and α-methylstyrene, and styrene is more preferable. Specifically, [A] is methyl methacrylate, and [B] is styrene.

The copolymerization ratio of each monomer of the acrylic random copolymer is 60 to 9 for the acrylic monomer [A].
The range is preferably 8% by weight, 1 to 25% by weight of the aromatic vinyl monomer [B], and 1 to 15% by weight of the maleic anhydride [C]. When [A] is 60% by weight or less, the acrylic random copolymer (c) has poor compatibility with the raw material resin component, and when it is 98% by weight or more, it does not exhibit the effect as a compatibilizer.

On the other hand, if [B] is 1% by weight or less, it is substantially difficult to produce, and if it is 25% by weight or more, the effect as a compatibilizer is not exhibited. Further, when [C] is 1% by weight or less, no acid anhydride functional group reactive with polyamide is provided, so that the compatibilizing effect is not exhibited. Worse.

The molecular weight of this acrylic random copolymer (c) is such that the number average molecular weight (Mn) by GPO measured at 40 ° C. using THF as an eluent and polymethyl methacrylate as a standard is 10,000-500. It is preferably in the range of 2,000. Those having Mn of 10,000 or less have a low effect of addition as a compatibilizer. On the other hand, when Mn is 5
If it is not less than 000, the melt flow of the acrylic random copolymer (c) alone is low, and therefore the melt flowability of the final composition is low, which is disadvantageous. A more preferred molecular weight range is from 20,000 to 200,000.

This acrylic random copolymer (c)
Can be produced by a usual radical polymerization method.For example, after dissolving an aromatic vinyl monomer and maleic anhydride in an acrylic monomer, a small amount of an organic peroxide such as benzoyl peroxide or lauroyl peroxide is used. Then, the mixture is transferred to a polymerization tank, and can be polymerized at a polymerization temperature of 60 to 120 ° C. by a continuous bulk polymerization method or a batch bulk polymerization method.
Examples of such an acrylic random copolymer include HW-55 manufactured by Lahm or Delpet 980N manufactured by Asahi Kasei Corporation, and Delpet 982J similarly.

(Production of final composition) The resin composition of the present invention is mainly composed of the above-mentioned three components of the ABS resin (a), the polyamide resin (b) and the acrylic random copolymer (c). It is. The mixing ratio of these three components is as follows: (a) 20 to 80 parts by weight of an ABS resin, (b) 100 parts by weight of a composition composed of 80 to 20 parts by weight of a polyamide resin, and (c) 2 to 30 parts of an acrylic random copolymer. Add parts by weight.

If the amount of the ABS resin in this composition is less than 20 parts by weight, the impact resistance and dimensional stability of the final composition are not sufficient, and if it exceeds 80 parts by weight, the chemical resistance of the final composition is low. If the amount of the polyamide resin is less than 20 parts by weight, the chemical resistance of the final composition is not sufficient, while if it exceeds 80 parts by weight, the dimensional stability of the molded article is poor.

Next, the acrylic random copolymer (c)
In the total composition is 2 to 100 parts by weight of the composition comprising the ABS resin (a) and the polyamide resin (b).
30 parts by weight, acrylic random copolymer (c)
If the content is less than 2 parts by weight, the effect of addition as a compatibilizer will be poor. Conversely, if it exceeds 30 parts by weight, the impact resistance and melt fluidity of the final composition will deteriorate, which is not preferable. A more preferable addition ratio is 5 to 15 parts by weight.

The polyamide resin composition of the present invention comprises ABS
The resin (a), the polyamide resin (b), and the acryl-based random copolymer (c) may be melted and kneaded using a usual blending method, for example, using an extruder, a kneader, a roll, or the like. A preferable method is obtained by mixing powdery raw materials using a Henschel mixer or the like, heating and melting the mixture using an extruder, extruding the mixture, and cutting into pellets.

(Addition of Additives and the Like) The thermoplastic resin composition of the present invention may contain various additives, such as plasticizers, antioxidants, stabilizers, inorganic fillers, and glass fibers. Reinforcing agents, pigments, dyes and the like can be selected and used. Among these additives, the filling amount of a reinforcing agent such as an inorganic filler and glass fiber must be suppressed to 60 parts by weight or less based on 100 parts by weight of the final resin composition. Addition of more than this significantly reduces the resin surface appearance.

Further, a flame retardant can be added to the thermoplastic resin composition of the present invention. As the flame retardant, a phosphorus compound such as triphenyl phosphate, a halogen compound such as decabromodiphenyl oxide, a metal hydroxide such as Mg (OH) _{2, and the} like are used.

The filling amount of these flame retardants is 100
It is necessary to suppress the content to 40 parts by weight or less per part by weight. Addition of more than this lowers the physical properties of the final composition.

[0031]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The addition ratios in the examples are all parts by weight.

First, ABS used in Examples and Comparative Examples
The resin (a), the polyamide resin (b), and the acrylic random copolymer (c) will be described in detail. Production of ABS resins (a-1 to a-4) having different amounts of rubber In a stainless steel reactor equipped with a stirrer, 1,960 g of polybutadiene latex (average particle size: 0.4 μ, gel content: 70%) was calculated as a solid content. And disproportionated potassium rosinate 45
g, styrene (ST), 1,080 g, acrylonitrile (AN), 420 g, tertiary decyl mercaptan (TDM), 10 g, potassium hydroxide, 2 g, and water, 6,000 g. Warm water was added and heated. Reactor temperature 4
When the temperature reached 0 ° C., 10 g of sodium pyrophosphate, 12.5 g of glucose and 0.2 g of ferrous sulfide were added to 500 g of water.
And a solution in which cumene hydroperoxide (C
HP).

While stirring the mixture, the warm water in the jacket was maintained at 70 ° C. and reacted for 60 minutes (graft polymerization step).

Subsequently, ST1,080 g, AN420
g, 10 g of TDM, 2 g of potassium hydroxide, 45 g of disproportionated potassium rosinate, 5 g of CHP, and 3,500 g of water were continuously added over 1.5 hours.
The polymerization conversion was 98%. The rubber content of the obtained polymer was 40%, the weight ratio of AN / ST was 25/75, and the graft ratio was 50%.

In order to control the amount of the rubbery polymer and the weight ratio of AN / ST, polybutadiene latex and ABS resin (a-1 to α-1) having different amounts of AN / ST were used.
a-4) was obtained. The contents are shown in Table 1.

Polyamide resin (b-1, b-2) The polyamide resin used in Examples and Comparative Examples was Unitika Nylon (polyamide 6 resin) A manufactured by Unitika Ltd.
1030 BRL (η _rel = 2.6, amino terminal group concentration = 0.058 mmol / g), and (polyamide 66 resin) A100 (η _rel = 2.70, amino terminal group concentration = 0.052 mmol / g), These resins are denoted by B-1 and B-2, respectively.

The acrylic random copolymer (c-1 to c-1)
c-4) The acrylic random copolymer used in Examples and Comparative Examples was prepared by changing the copolymerization amount of an aromatic vinyl monomer and maleic anhydride with respect to an acrylic monomer as shown in Table 2. These copolymers have c-1 to c-4
With the symbol.

(Example 1) ABS resin (a-1) was added to 5
0 parts, 50 parts of a polyamide resin (b-1), 10 parts of an acrylic random copolymer (c-1), and 0.2 part of Irganox 1076 as a heat stabilizer were weighed and mixed well with a Henschel mixer. did. This resin mixture was pelletized with a 40 mmφ single screw extruder manufactured by Osaka Seiki Co., Ltd. The extrusion temperature is 250 ° C. Then, the pellets were dried and an injection molding machine (TS-
100), a test piece for evaluating physical properties was prepared.

The physical properties of the molded test pieces were measured by the methods shown in Table 3. Table 4 shows the physical property evaluation results. This system is
The balance of S, IS, etc. is excellent, and no delamination at the time of cutting is observed.

(Embodiments 2 and 3)
Example except that a-2 and a-3 were used instead of -1.
The procedure was performed exactly as in 1. Table 4 shows the results. The composition of this example was also excellent in performance.

(Embodiment 4) In the embodiment 1, b-1
Was carried out in exactly the same manner as in Example 1 except that b-2 was used instead of b. Table 4 shows the results.

(Examples 5 and 6) In Example 1
This is an example in which the mixing ratio of -1 and b-1 is changed as shown in Table 4. Others were carried out similarly to Example 1. Table 4 shows the results.

Comparative Example 1 Comparative Example 1 is the same as Example 1
In this example, ABS (a-4) having a rubber amount of 5% and being outside the claims was used in place of a-1. In this case, the IS was extremely low.

(Comparative Examples 2 and 3) In Example 1,
This is an example in which the blending ratio of a-1 and a-1 exceeds the scope of the claims. Table 4 shows the results.
S and EB are low. Comparative Example 3 had a remarkably low IS. Further, Comparative Example 3 was very poor in impact resistance.

(Embodiments 7, 8, 9)
1 except that the addition amount of the acrylic random copolymer (c-1) was changed to 5, 15 and 20 parts, respectively.
This is an example of a system similar to Example 1. In this case, excellent impact resistance was obtained, and no delamination was observed. Table 5 shows the evaluation results of the physical properties.

(Example 10) In this example, instead of the acrylic random copolymer (c-1) used in Example 1, an acrylic random copolymer having a maleic anhydride content of 10% was used. This is an example using c-3). This example was also excellent in impact resistance, and no delamination was observed.

(Comparative Examples 4 and 5) Comparative Examples 4 and 5 are examples in which the addition amount of c-1 in Example 1 was 1 and 40 parts, respectively, which were outside the scope of the claims. Comparative Example 4 had remarkably poor impact resistance, and delamination was observed in the molded product. Further, Comparative Example 5 had extremely low fluidity.

Comparative Example 6 Comparative Example 6 is an example in which an acrylic copolymer c-3 having a maleic anhydride content of 20% was used instead of c-1 in Example 1. IS
Was extremely low, and delamination was observed.

Comparative Example 7 Comparative Example 7 is the same as Example 1
In this example, an acrylic copolymer c-4 was used in place of c-1. IS was extremely low, and delamination was also remarkable.

[0050]

According to the present invention, simple (A)
In contrast to the (BS resin / polyamide resin) composition, the composition of the present invention provides a composition comprising an ABS resin, a polyamide resin, and an acrylic copolymer as a compatibilizer, and has a higher impact resistance and a higher moldability. It is possible to obtain a low-cost (ABS / polyamide) compatible alloy having good delamination and no delamination, and to apply the alloy to an exterior material of an automobile or an exterior of a power tool.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI (C08L 77/00 55:02 33:10) (58) Investigated field (Int.Cl. ⁷ , DB name) C08L 77/00 -77/12 C08L 51/00-51/10 C08L 55/02 C08L 33/00-33/26

Claims (1)

(57) [Claims] 1. a) 10 to 70 parts by weight of a rubbery polymer, 50 to 80% by weight of an aromatic vinyl monomer, 20 to 40% by weight of a vinyl cyanide monomer, and a vinyl monomer copolymerizable therewith A monomer mixture of 30 to 90% by weight
Graft copolymer grafted with parts by weight, 20 to 80
Parts by weight and b) between 0.010 and 0.100 amino terminal groups.
mmol / g containing, relative viscosity · _{eta rel} of the solution at a concentration of 1 g / dl in 96% sulfuric acid, 2.0 25 ° C.
C) 60-98% by weight of a methacrylic acid ester monomer [A] and an aromatic vinyl monomer [100% by weight, based on a polyamide resin of 80 to 7.0 parts by weight and a resin composition of 80 to 20 parts by weight. B] A polyamide resin composition having excellent impact resistance, comprising 2 to 30 parts by weight of an acrylic random copolymer comprising 1 to 25% by weight and 1 to 15% by weight of maleic anhydride [C].