JP2744667B2 - Resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin composition used as a molding material. More specifically, the present invention relates to a thermoplastic resin composition comprising a polyamide resin, a thermoplastic polyester resin, and a β-hydroxyalkylated polyamide resin, which has good surface appearance of a molded article and excellent impact resistance.

(Prior Art) In recent years, polyamide resins have been used as molding materials because of their excellent physical and chemical properties. This is because polyamide resin has high mechanical strength, excellent abrasion resistance, chemical resistance, heat resistance and relatively high electrical properties in thermoplastic resin, and has sufficient performance as engineering plastics It depends. However, on the other hand, it has unfavorable properties such as dimensional change due to water absorption due to amide group (-CONH-) and decrease in mechanical strength, and therefore, the marketability as a molding material is sometimes limited. It was.

In addition, the thermoplastic polyester resin has no physical property deterioration due to water absorption, and furthermore, excellent physical properties similar to polyamide resin,
It has chemical properties and is widely used as a molding material.
However, the mechanical strength is significantly reduced when exposed to hot water for a long time.

Attempts have been made to mix the polyamide resin and the thermoplastic polyester resin to compensate for the disadvantages of both, but simply mixing the two would impair the excellent performance and make it impossible to put it to practical use. Met.

Conventional mixing methods for preventing a decrease in mechanical strength due to simple mixing and compensating for the disadvantages of both methods include, for example, a method of mixing at the polymerization stage in JP-A-51-103191 and JP-A-56-42645. Has been proposed, but the equipment is also large-scale,
It was not practical due to the time required for mixing.

(Problems to be Solved by the Invention) Accordingly, a need has arisen for a resin composition which is provided by a simpler method, does not impair the excellent properties of polyamide resin and thermoplastic polyester resin, and has improved defects of both. Is growing.

(Means for Solving the Problems) The present inventors mix the polyamide resin and the thermoplastic polyester resin by simple melt-kneading using an extruder, so that the excellent properties of both are not impaired. As a result of diligent studies aimed at obtaining a resin composition with improved disadvantages, a resin composition obtained by uniformly mixing a polyamide resin, a thermoplastic polyester resin and a β-hydroxyalkylated polyamide resin has been surprisingly described. The inventors have found that all the objects of the invention are satisfied, and have reached the present invention.

That is, the present invention relates to a resin composition comprising a polyamide resin (a), a thermoplastic polyester resin (b), and a β-hydroxyalkylated polyamide resin (c).

The polyamide resin (a) used in the present invention includes:
Examples include various polyamide resins obtained by polycondensation of a lactam having three or more rings, ω-aminocarboxylic acid, dibasic acid and diamine.

Specifically, ε-caprolactam, aminocaproic acid, enantholactam, 7-aminoheptanoic acid, polymers such as 11-aminoundecanoic acid, or butanediamine, hexamethylenediamine, nonamethylenediamine,
Undecamethylenediamine, dodecamethylenediamine,
Polymers obtained by polycondensing diamines such as meta-xylylenediamine and dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sepatin acid, dodecane dibasic acid, and glutaric acid, or copolymers thereof Coalescence.

More specifically, nylon 46, nylon 6, nylon
66, nylon 610, nylon 11, nylon 12, nylon 6
Examples thereof include aromatic polyamide resins such as 12 and aromatic polyamide resins such as polyhexamethylene terephthalamide, polyhexamethylene isophthalamide, and xylylene group-containing polyamide. Of the above-listed polyamide resins, nylon 6, nylon 66 and nylon 12 are particularly preferred.

The average molecular weight of the polyamide resin (a) used in the present invention is preferably in the range of 10,000 to 35,000.

Thermoplastic polyester resin (b) used in the present invention
Glycols having 2 to 6 carbon atoms such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol and hexanediol as glycol components, and terephthalic acid, isophthalic acid and halogens thereof as dicarboxylic acid components. For example, a thermoplastic polyester resin having a skeleton combined with a dicarboxylic acid such as a substituted nucleus and an alkyl nucleus, and the like, specifically, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyhexylene terephthalate, In addition to polyethylene naphthalate, polybutylene naphthalate, polyethylene-1,2-bis (phenoxy) ethane-4,4'-dicarboxylate, polyethylene isophthalate / terephthalate Polybutylene isophthalate /
Copolymerized polyesters such as terephthalate, polybutylene terephthalate / decanedicarboxylate and the like can be mentioned. Of these, polyester terephthalate and polybutylene terephthalate, which are well-balanced in mechanical properties, moldability, and the like, are preferable.

Thermoplastic polyester resin (b) used in the present invention
Is preferably in the range of 10,000 to 35,000.

The β-hydroxyalkylated polyamide resin (c) in the present invention refers to a β-hydroxyalkylated polyamide resin obtained by reacting a polyamide resin with an alkylene oxide having 2 to 4 carbon atoms. The polyamide resins that can be used here are various polyamide resins obtained by polycondensation of a lactam having three or more rings, ω-aminocarboxylic acid, dibasic acid and diamine.

Specifically, ε-caprolactam, aminocaproic acid, enantholactam, 7-aminoheptanoic acid, polymers such as 11-aminoundecanoic acid, or butadiamine;
Diamines such as hexamethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, meta-xylylenediamine, and terephthalic acid,
Examples include a polymer obtained by polycondensation with a dicarboxylic acid such as isophthalic acid, adipic acid, sepatic acid, dodecane dibasic acid, glutaric acid, or a copolymer thereof.

More specifically, nylon 46, nylon 6, nylon
66, nylon 610, nylon 11, nylon 12, nylon 6
Examples thereof include aromatic polyamide resins such as 12 and aromatic polyamide resins such as polyhexamethylene terephthalamide, polyhexamethylene isophthalamide, and xylylene group-containing polyamide.

Among the polyamide resins listed above, the repeating structural unit is preferably the same as the polyamide resin (a), for example, nylon 6, nylon 66, nylon
12 is preferably used.

The average molecular weight of the polyamide resin used is 5,
The range of 000 to 35,000 is preferred. Then, more preferably an average molecular weight M _e is close polyamide resin (a) an average molecular weight M _a and β- hydroxyalkylation pre polyamide resin (e), in particular with 0.5 ≦ M _e / M _a ≦ 1.5 Preferably, there is.

The alkylene oxide to be reacted with the polyamide resin (e) preferably has 2 to 4 carbon atoms, and ethylene oxide and propylene oxide are preferably used.

The above β-hydroxyalkylated polyamide resin (c)
The weight of the alkylene oxide added to the polyamide resin (e) and the ratio of the β-hydroxyalkylated amide bond to the total number of amide bonds in the polyamide resin (e) are not particularly limited and can be freely changed depending on the purpose. Can be done.

As a method for obtaining the β-hydroxyalkylated polyamide resin (c), a conventionally known method is used. For example, "Journal of Polymer Science," Volume 15, 42
7 (1955), JP-A-1-92223 and the like, but the production method is not particularly limited.

The resin composition of the present invention comprises the polyamide resin (a),
It is composed of a thermoplastic polyester resin (b) and a β-hydroxyalkylated polyamide resin (c), and it is essential that at least the above three components are contained.

In the resin composition of the present invention, the remaining resin mixture excluding the β-hydroxyalkylated polyamide resin (c) is:
It is composed of a polyamide resin (a) and a thermoplastic polyester resin (b), and the ratio of the components (a) and (b) is not particularly limited, and any ratio can be used. As the resin mixture, preferably, a polyamide resin (a) having a ratio of 20 to 95% by weight and a thermoplastic polyester resin (b) having a ratio of 80 to 5% by weight are used.

The ratio of the β-hydroxyalkylated polyamide resin (c) in the resin composition of the present invention is not particularly limited, but is preferably used at a ratio of 1 to 40% by weight.

The preferred ratio of each component of the resin composition of the present invention,
Resin mixture (a) consisting of 20 to 95% by weight of polyamide resin (a) and 80 to 5% by weight of thermoplastic polyester resin (b)
+ (B) and the weight ratio of β-hydroxyalkylated polyamide resin (c) are (a) + (b) / (C) = 60 / 40-99 /
1, but is not limited to this.

Further, for the resin composition of the present invention, glass fiber, metal fiber, aramid fiber, ceramic fiber, potassium whisker, carbon fiber, fibrous reinforcing agent such as asbestos, talc, calcium carbonate, mica, clay, oxidized Titanium,
A granular reinforcing agent such as aluminum oxide, glass flake, milled fiber, metal flake, and metal powder may be mixed. In particular, by mixing the chopped strand type glass fiber with the resin composition of the present invention at a weight ratio of the resin composition / glass fiber = 50/50 to 90/10, the mechanical strength and heat resistance temperature are greatly increased. In addition to improving the water resistance, the water resistance can be further improved, which is preferable in achieving the object of the present invention.

Incidentally, in the resin composition of the present invention, further a heat stabilizer,
One or more additives such as an oxidation stabilizer, a light stabilizer, a lubricant, a pigment, a flame retardant, and a plasticizer may be mixed.

The method for producing the resin composition of the present invention is not particularly limited, but the polyamide resin (a), thermoplastic polyester resin (b), β-hydroxyalkylated polyamide resin (c), and Various additives used accordingly can be easily produced by melt-kneading by a commonly used method. As the kneader, for example, an extruder, a Banbury mixer, a super mixer, a roll, a kneader, and the like are used, and among them, an extruder is used, and a method of melt-kneading at a resin temperature of 180 to 350 ° C is advantageous. is there.

(Examples) Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In the following examples,% and parts indicate% by weight and parts by weight, respectively.

Β-hydroxyalkylated polyamide resin shown below,
Polyamide resin and thermoplastic polyester resin were used in the following Examples and Comparative Examples.

(1) β-Hydroxyalkylated Polyamide Resin A nylon resin powder (Ube Nylon 6, P1022 manufactured by Ube Industries, Ltd., P1022) was used as a polyamide resin, and β was obtained by adding 10 parts of ethylene oxide to 100 parts of nylon 6. -Hydroxyalkylated polyamide resin (Nylon 6-EOA-YIK-2S1, manufactured by Nisso Oil Chemical Co., Ltd., hereinafter referred to as EOA-1)
Β-hydroxyalkylated polyamide resin (Nylon 6-EOA-YIK-2S2 manufactured by Nisso Oil Chemical Co., Ltd .;
OA-2) As a polyamide resin, powder of nylon 6 (Ube nylon 6, P1011 manufactured by Ube Industries, Ltd., P1011) was used, and β-hydroxyalkylation in which 70 parts of ethylene oxide was added to 100 parts of nylon 6 Polyamide resin (Nylon 6-EOA-YIF-15S1, manufactured by Nisso Oil Chemical Co., Ltd., hereinafter referred to as EOA-7) (2) Polyamide resin nylon 6 (Ube Nylon 6, 1022 manufactured by Ube Industries, Ltd.)
B) Hereinafter referred to as NY6. (3) Thermoplastic polyester resin polybutylene terephthalate (Duranex 600FP manufactured by Polyplastics Co., Ltd.) referred to as PBT6. Examples 1-3 NY6 and PBT whose ratio is NY6 / PBT = (70 %) / (30
%) And 10 parts of EOA-1, EOA-
2 or EOA-7 was added to make the total amount 100 parts, and then mixed at room temperature for 15 minutes using a Henschel mixer.

The obtained resin mixture was heated at 240 ° C using a 40 mmφ single screw extruder.
And melt-kneaded into pellets, which were formed at 240 ° C. using a screw-type injection molding machine to prepare predetermined test pieces.

For these test pieces, the flexural modulus (sample thickness
3.2 mm, measurement temperature 23 ° C, hereinafter referred to as FM. ) JISK7203
The JIS K7110 shows the Izod impact strength (sample thickness 3.2 mm, measurement temperature 23 ° C, with cutting notch, referred to as IS below).
Heat deformation temperature (sample thickness 3.2mm, bending stress 4.6kgf /
cm ² and 18.6 kgf / cm ² , without annealing, hereinafter referred to as HDT. ) Was measured according to JISK7207.

Comparative Example 1 For comparison, resin compositions using NY6 and PBT6 at a ratio of (70%) / (30%) without using EOA-1, EOA-2 or EOA-7 were used. Was melt-kneaded in the same manner as described above and injection molded to obtain a test piece.

Physical properties of these test pieces were measured by the same method as shown in Examples 1 to 3.

Example 4 The ratio of NY6 and PBT is NY6 / PBT = (50%) / (50%)
Then, 10 parts of EOA-2 were added to adjust the total amount to 100 parts, and then melt-kneaded in the same manner as shown in Examples 1 to 3, and then injection-molded and tested. I got a piece.

Physical properties of these test pieces were measured by the same method as shown in Examples 1 to 3.

Comparative Example 2 For comparison, NY6 and PBT were used without using EOA-2 (50
%) / (50%) in Example 1
In the same manner as in the method shown in No. 3, melt-kneading was performed and injection molding was performed to obtain a test piece.

Physical properties of these test pieces were measured by the same method as shown in Examples 1 to 3.

Example 5 NY6 and PBT were weighed so that the ratio became NY6 / PBT = (30%) / (70%), and 10 parts of EOA-2 was added to make a total of 100.
After that, the mixture was melt-kneaded in the same manner as in Examples 1 to 3, and injection molded to obtain a test piece.

Physical properties of these test pieces were measured by the same method as shown in Examples 1 to 3.

Comparative Example 3 For comparison, NY6 and PBT were used without using EOA-2 (30
%) / (70%) was melt-kneaded in the same manner as in Examples 1 to 3, and injection molded to obtain test specimens.

Physical properties of these test pieces were measured by the same method as shown in Examples 1 to 3.

 The results are summarized in Table 1.

(Effect of the Invention) Generally, the mixing of different polymers has extremely poor compatibility,
It is difficult to obtain a uniform sea-island structure, which undesirably affects the appearance of molded pieces and the mechanical, physical and chemical properties of the resulting mixed composition.

However, in the present invention, by mixing the three components of the polyamide resin, the thermoplastic polyester resin and the β-hydroxyalkylated polyamide resin, it is possible to achieve extremely excellent dispersion, and the polyester resin and the polyamide resin inherently Thus, a resin composition having high impact resistance, which is significantly improved in terms of water resistance, and giving a good appearance to a molded product without losing the above properties was obtained. The object of the present invention is achieved only when all the above conditions are satisfied.

Claims (2)

(57) [Claims] 1. A resin composition comprising a polyamide resin (a), a thermoplastic polyester resin (b) and a β-hydroxyalkylated polyamide resin (c). 2. The weight ratio of the polyamide resin (a) to the thermoplastic polyester resin (b) is (a) / (b) = 20 / 80-95 /
5, and the weight ratio of the resin mixture (a) + (b) to the β-hydroxyalkylated polyamide resin (c) is [(a) + (b)] / (c) = 60/40 to 99/1. The resin composition according to claim 1, wherein