JPH06340801A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a molding resin composition which has a low water absorbency and excellent mechanical strength, flexibility, heat resistance, etc., by mixing given amounts of a polyamide resin, a polyester resin and specific vinyl polymers respectively. CONSTITUTION:The resin composition comprises 10-90 pts.wt. (pts. hereunder) of a polyamide resin (e.g. nylon 6), 90-10 pts. of a polyester resin (e.g. polybutylene terephthalate), 0.1-10 pts. of a vinyl polymer which contains epoxy groups and comprises 70-wt.% or less of an aromatic vinyl monomer (e.g. styrene-acrylonitrile-glycidyl methacrylate copolymer) and 0.1-10 pts. of a vinyl polymer which contains alpha,beta-unsaturated carboxylic acids and comprises 70wt.% or less of an aromatic vinyl monomer (e.g. styrene-acrylonitrile-maleic anhydride copolymer).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition comprising a polyamide resin, a polyester resin and a vinyl copolymer, which has a low water absorption property and is excellent in properties such as mechanical strength, flexibility and heat resistance.

[0002]

BACKGROUND OF THE INVENTION Problems to be Solved by the Invention Polyamide resins represented by nylon 6 and nylon 66 are excellent in mechanical strength, abrasion resistance, solvent resistance and heat resistance.
Since it has good productivity in melt molding, it is widely used as engineering plastics in the fields of machine parts, automobile parts, electric / electronic parts and the like. However, it has water absorption due to an amide group (-CONH-), and when it absorbs water, the tensile rupture elongation and the flexibility represented by impact strength are improved, but the tensile rupture strength is significantly reduced. In addition, since it lacks flexibility when it is not absorbing water, there is a limitation in the field of use.

On the other hand, thermoplastic polyester resins represented by polyethylene terephthalate and polybutylene terephthalate are also excellent in mechanical strength and chemical resistance, and
Since it has low water absorption, it is used in various fields. However, there are drawbacks such as low heat resistance and impact strength, and low bending properties as compared with nylon 6 and nylon 66 that absorb low water. On the other hand, many attempts have been made to utilize a resin composition obtained by melt-blending both the polyamide resin and the thermoplastic polyester resin in order to make use of the excellent properties of the polyamide resin and the drawbacks of the both. But,
It is generally well known that when resins of different types are melt mixed, the dispersibility of the resins is poor and the mechanical strength and impact strength of the mixture are lower than the values expected from the mixing ratio of the two. Even when a normal polyamide resin and a thermoplastic polyester resin are melt-mixed, the dispersibility of both components is poor, and only a mixture with low mechanical strength or flexibility can be obtained, and the molded product suffers delamination, etc. There is
It was far from practical use.

As a mixing method for preventing deterioration of mechanical strength due to simple mixing and compensating for the defects of both, for example, JP-A-51-103191 and JP-A-56-426.
No. 45, a method of mixing at the polymerization stage has been proposed, but the apparatus is large-scale and mixing is time-consuming, which is not practical.

JP-A-54-31456 and JP-A-6-63
0-86163, JP-A-55-92759, JP-A-4.
No. 239056 discloses a resin composition in which various compounds effective for improving dispersibility and impact strength of both resins are used in combination. By these methods, the dispersibility and flexibility of the resins to be mixed are improved, but the mechanical strength and heat resistance are still insufficient.

An object of the present invention is a resin composition containing a polyamide resin and a thermoplastic polyester resin as main components,
An object of the present invention is to provide a resin composition having low water absorption and excellent properties such as mechanical strength, flexibility and heat resistance.

[0007]

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, a specific vinyl polymer having a limited aromatic monomer content in a mixture of a known polyamide resin and a known polyester resin. It has been found that a resin composition having good dispersibility between resins, low water absorption, and good mechanical properties and resistance to surface peeling can be obtained by the addition of the above.

That is, the present invention comprises: A) 10 to 90 parts by weight of polyamide resin B) 90 to 10 parts by weight of polyester resin C) Contains unsaturated epoxy groups and 70% by weight of aromatic vinyl monomer. The following vinyl polymers 0.1 to
10 parts by weight D) A molding containing 0.1 to 10 parts by weight of a vinyl polymer containing an α, β unsaturated carboxylic acid and having an aromatic vinyl monomer content of 70% by weight or less. A resin composition is provided.

The present invention will be specifically described below.

The polyamide resin used in the present invention is a known injection-moldable one, and is a polymer obtained by polymerizing aminocarboxylic acid, lactam or diamine and dicarboxylic acid as monomers.

Specifically, polymers such as ε-caprolactam, aminocaproic acid, enanthlactam, 7-aminoheptanoic acid and 11-aminoundecanoic acid, or butanediamine, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine. , With diamines such as dodecamethylenediamine and metaxylylenediamine,
Examples thereof include polymers obtained by polycondensing dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sepatic acid, dodecane dibasic acid, and glutaric acid, or copolymers thereof.

More specifically, it contains an aliphatic polyamide resin such as nylon 46, nylon 6, nylon 66, nylon 610, nylon 11, nylon 12, nylon 612, polyhexamethylene terephthalamide, polyhexamethylene isophthalamide, and xylylene group. An aromatic polyamide resin such as polyamide can be exemplified. Among the polyamide resins listed above, nylon 6, nylon 66 and nylon 12 are particularly preferable.

The number average molecular weight of the polyamide resin used is preferably from 10,000 to 35,000.

The polyester resin used in the present invention is also a known injection-moldable resin, and has a glycol component having 2 to 6 carbon atoms such as ethylene glycol, propylene glycol, butanediol, neo. Examples of glycol and dicarboxylic acid components such as pentyl glycol and hexanediol include terephthalic acid, isophthalic acid and halogenated nucleus substitution products thereof,
A thermoplastic polyester resin having a skeleton in which a dicarboxylic acid such as an alkyl nucleus substitution product is combined, and more specifically, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyhexylene terephthalate, polyethylene naphthalate, polybutylene naphthalate. In addition to phthalate, polyethylene-1,2-bis (phenoxy) ethane-4,4'-dicarboxylate, polyethylene isophthalate / terephthalate, polybutylene isophthalate / terephthalate, polybutylene terephthalate / decanedicarboxylate, etc. As mentioned above, a copolyester can be mentioned.
Of these, polyethylene terephthalate and polybutylene terephthalate, which are well-balanced in mechanical properties and moldability, are preferred.

The number average molecular weight of the thermoplastic polyester resin used is preferably in the range of 10,000 to 35,000.

The vinyl polymer (C) in the present invention
(D) has a structure obtained by polymerizing or copolymerizing one or more vinyl monomers having an aromatic vinyl monomer content of 70% by weight or less, and (C) is a molecule And (D) is a polymer containing an unsaturated epoxide group and an α, β unsaturated carboxylic acid in the molecule.

The vinyl monomer used for the polymerization of the vinyl polymers (C) and (D) is an aromatic vinyl monomer.
Examples of vinyl monomers other than aromatics such as styrene, α-methylstyrene, vinyltoluene, etc. include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, methyl methacrylate, ethyl methacrylate, methyl acrylate. , (Meth) acrylic acid ester-based monomers such as butyl acrylate, maleimide-based monomers such as maleimide, N-methylmaleimide and N-phenylmaleimide, olefin-based monomers such as ethylene and propylene, and vinyl chloride, Examples thereof include vinyl-based monomers such as vinyl acetate and butadiene.

The method for introducing an unsaturated epoxy group into the vinyl polymer (C) is not particularly limited, and examples thereof include glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, 2 methylallyl glycidyl ether and allylphenol glycidyl. A method of copolymerizing ether or the like, particularly preferably glycidyl methacrylate with a vinyl monomer, can be used.

The method for introducing α, β unsaturated carboxylic acid into the vinyl polymer (D) is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid, methylmaleic acid, chloromaleic acid and itacone. Acid, citraconic acid,
A method of copolymerizing fumaric acid, crotonic acid, mesaconic acid, succinic acid, tetrahydrophthalic acid or their anhydrides, particularly preferably maleic anhydride with a vinyl monomer can be used.

The content of each functional group may be very small and may be large as long as the performance of the resin is not impaired, but particularly preferably 1 to 30% by weight.

As a method for polymerizing the polymers (C) and (D), so-called known radical copolymerization is used. As a specific method of this radical copolymerization, solution polymerization,
It is selected from emulsion polymerization, bulk polymerization, suspension polymerization and the like. The number average molecular weight of the obtained polymer is preferably in the range of 10,000 to 150,000.

The proportion of the polymers (C) and (D) in the molding resin composition of the present invention is 0.1 to 10% by weight, respectively.
Below this range, as in the case where the contents of unsaturated dicarboxylic acid anhydride and unsaturated epoxy compound in the polymers (C) and (D) are small, between the polyamide resin and the thermoplastic polyester resin, The dispersion state becomes non-uniform,
The mechanical properties cannot be satisfied either. On the other hand, when the content exceeds this range, the properties of the resin composition obtained are manifested by the properties of the vinyl-based polymer possessed by the polymers (C) and (D), and polyester,
Compared with polyamide or its composition, it becomes unsatisfactory in terms of heat resistance and mechanical properties.

The remaining molding resin composition excluding the polymers (C) and (D) is composed of a polyamide resin and a thermoplastic polyester resin, the proportion of which is 10 to 90 parts by weight of the polyamide resin, 9 thermoplastic polyester resin
The amount is 0 to 10 parts by weight, and any ratio can be used within this range. When the content of the polyamide resin is 10 parts or less and the content of the polyester resin is 90 parts by weight or more, the disadvantage of the polyester resin represented by heat resistance is conversely, and when the content of the polyamide resin is 90 parts by weight or more and the polyester resin is 10 parts by weight or less, the water absorption is represented. It is not possible to make up for the drawbacks of the polyamide resins mentioned.

With respect to the resin composition of the present invention,
Glass fiber, metal fiber, aramid fiber, ceramic fiber, potassium whisker titanate, carbon fiber, fibrous reinforcing agent such as asbestos, talc, calcium carbonate, mica,
Granular reinforcing agents such as clay, titanium oxide, aluminum oxide, glass flakes, milled fibers, metal flakes, and metal powder may be mixed. In particular, chopped strand type glass fiber is used as the resin composition 5 of the present invention.
By mixing 10 to 50% by weight with respect to 0 to 90% by weight, not only the mechanical strength and heat resistant temperature are significantly improved, but also the water resistance performance can be further improved.
It is preferable in achieving the object of the present invention.

Further, in the composition of the present invention, other thermoplastic resins may be supplementarily used in a small amount depending on the purpose. The other thermoplastic resin used here may be any one as long as it is a thermoplastic resin stable at high temperature. Examples thereof include polyethylene, polycarbonate, polyphenylene sulfide, polyphenylene oxide, polyacetal, polysulfone, polyether sulfone, polyetherimide, polyetherketone, and fluororesin. Further, these thermoplastic resins may be used as a mixture of two or more kinds.

In the composition of the present invention, known substances generally added to thermoplastic resins, that is, stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents, flame retardants, dyes and pigments, etc. A colorant, a lubricant, a crystallization accelerator, a crystal nucleating agent and the like can be appropriately added depending on the required performance.

The method for producing the resin composition of the present invention is not particularly limited, and includes, for example, (A) (B) (C) (D)
It is manufactured by melt-kneading the resin mixture of (1) with a Banbury mixer, a roll, an extruder or the like.

[0028]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The evaluated items and measuring methods are as follows.

Tensile properties: Compliant with ASTM D-638. Notched Izod impact strength: Compliant with ASTM D-256. Molded product surface condition: After molding an ASTM TYPE PE type dumbbell test piece and attaching cellophane tape to the test piece. The state of peeling of the surface of the molded product when it was quickly peeled off was evaluated by visual observation on a scale of 5 levels.

[0030] Preparation of vinyl polymer (C) (D) C-1: 65 parts of styrene, 30 parts of acrylonitrile, and 5 parts of glycidyl methacrylate were subjected to suspension polymerization to prepare a vinyl polymer (C-1). According to GPC measurement, the number average molecular weight of the obtained polymer C-1 was 100,000.

C-2: A vinyl polymer (C-2) was prepared by suspension polymerization of 5 parts of styrene, 85 parts of methyl methacrylate and 10 parts of glycidyl methacrylate. According to GPC measurement, the number average molecular weight of the obtained polymer C-2 was 90,
It was 000.

C-3: 71 parts of styrene, 28 parts of acrylonitrile, and 1 part of glycidyl methacrylate were subjected to suspension polymerization to prepare a modified vinyl polymer (C-3). The number average molecular weight of the obtained modified polymer was 90,000.

D-1: A vinyl polymer (D-1) was prepared by suspension polymerization of 65 parts of styrene, 30 parts of acrylonitrile and 5 parts of maleic anhydride. According to GPC measurement, the number average molecular weight of the obtained polymer D-1 was 110,000.

D-2: A vinyl polymer (D-2) was prepared by suspension polymerization of 5 parts of styrene, 85 parts of methyl methacrylate and 10 parts of maleic anhydride. According to GPC measurement,
The number average molecular weight of the obtained polymer D-1 is 100,000.
Met.

D-3: 90 parts of styrene, 10 parts of maleic anhydride, and 1.5 parts of AIBN were reacted in a 80 ° C. oil bath under a nitrogen atmosphere for 1 hour, further heated to 100 ° C. for 1 hour, and then reacted at room temperature. It was cooled to room temperature and precipitated with ethyl alcohol. The number average molecular weight of the obtained styrene-maleic anhydride copolymer was 31,000, and the amount of maleic anhydride in the copolymer was 9.9% by weight.

Examples 1 to 8 Nylon 6 (Ube Industries, Ltd., Ube Nylon 6 / 1013B) as component (A), PBT (Polyplastics Corp., Duranex 500F) as component (B).
The above polymers as components P), (C) and (D) are added and mixed in the proportions shown in Table 1, and then melt-kneaded with a twin-screw extruder,
A pelletized composition was prepared. Then, standard test pieces for measuring various physical properties were molded by injection molding and various properties were measured. The results are shown in Table 1.

Comparative Examples 1 to 4 For comparison, vinyl polymers (C) and (D) having an aromatic vinyl monomer content of 70% by weight or more were prepared and tested and compared in the same manner as in Examples. . The results are shown in Table 1.

[0038]

[Table 1]

[0039]

In general, a mixture of different polymers has extremely poor compatibility with each other. Therefore, it is possible to obtain a mixture having excellent extrusion process stability without impairing the surface appearance and mechanical properties of the molded product. It is difficult. However, in the present invention, in a mixture of a polyamide resin and a thermoplastic polyester, by blending a vinyl polymer having a limited content of aromatic vinyl monomers into the mixture, fine and uniform dispersion is possible, and the polyamide resin It is possible to obtain a molding material in which the hydrolysis resistance of the thermoplastic polyester resin and the water absorption of the polyamide resin are improved without losing the original performances of the thermoplastic polyester resin.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area C08L 25:02)

Claims (1)

[Claims] 1. A) 10 to 90 parts by weight of a polyamide resin B) 90 to 10 parts by weight of a polyester resin C) A vinyl-based polymer containing an epoxy group and containing 70% by weight or less of an aromatic vinyl monomer. 0.1 to 10 parts by weight of combined D) 0.1 to 10 parts by weight of a vinyl polymer containing an α, β unsaturated carboxylic acid and an aromatic vinyl monomer content of 70% by weight or less A molding resin composition comprising