JP2575796B2 - Resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a nylon 46 resin composition having improved thermal stability during hot melt molding such as injection molding.

(Prior Art) Nylon 46 is a known polyamide. For example, JP-A-56-149429 discloses a method for producing nylon 46. It is also known that nylon 46 has excellent properties as engineering plastics, especially excellent heat resistance.

For example, its melting point is 295 ° C, which is
It is not only higher than 20 ° C and 260 ° C for nylon 66, but also higher than 285 ° C for polyphenylene sulfide. As described above, since nylon 46 has a high melting point, it has excellent heat resistance and solder resistance expressed by the heat deformation temperature. In addition, the molding cycle is short because the crystallization speed is high and the ultimate degree of crystallinity is high, and the flowability is good, so the moldability is good. It also has high rigidity and excellent friction and creep resistance. As described above, nylon 46 is expected to be applied to engineering plastics from various fields because it has excellent heat resistance and mechanical properties in addition to the excellent chemical resistance of polyamide.

However, while nylon 46 has a high heat distortion temperature, its melting point and thermal decomposition temperature are close to each other, and there is a problem that decomposition is likely to occur during hot melt molding. For this reason, so-called burns often occurred on the surface of the molded article during injection molding. When the decomposition is remarkable, generation of silver streaks and deterioration of physical properties are observed.

Nylon 46 has such excellent chemical resistance, heat resistance and mechanical properties, but is inferior in stability at the time of hot-melt molding as described above, so that its improvement has been widely demanded.

(Problems to be Solved by the Invention) Accordingly, an object of the present invention is to prevent the stability of nylon 46 during hot-melt molding, particularly the occurrence of burns, without impairing the excellent properties of nylon 46.

(Means for Solving the Problems) The present inventors have made intensive studies to solve the above-mentioned problems of nylon 46, and as a result, by blending a specific modified polyolefin oligomer with nylon 46 resin, the object of the present invention was achieved. Have been found to be completely satisfied, and the present invention has been achieved.

That is, in the present invention, an α, β-unsaturated carboxylic acid or a derivative thereof is saponified with a polyolefin oligomer containing ethylene and / or propylene as a main component and a saponification value of 5 to 200 mg KOH / g per 100 parts by weight of nylon 46.
And a viscosity at 40 ° C of 100 to 50,
The present invention relates to a stabilized resin composition containing 0.1 to 10 parts by weight of a modified polyolefin oligomer in the range of 000 centipoise. By incorporating such a specific modified polyolefin oligomer into nylon 46,
It is quite surprising that it is possible to improve the stability during hot-melt molding, and particularly to prevent the occurrence of burns, without impairing the excellent properties of nylon 46, and this finding was first discovered by the present invention. It was done.

Nylon 46 used in the present invention includes polytetramethylene adipamide obtained from tetramethylene diamine and adipic acid and copolymerized polyamide having polytetramethylene adipamide unit as a main component. Further, another polyamide may be contained as a mixed component as long as the properties of nylon 46 are not impaired. The copolymerization component is not particularly limited, and a known amide-forming component can be used. Representative examples of the copolymerization component include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and paraaminomethylbenzoic acid, ε-caprolactam, ω
Lactams such as lauryl lactam, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, meta-xylylenediamine, Paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-
Diamines such as trimethylcyclohexane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine and adipic acid, suberic acid, azelaine Acid, sebacic acid, dotecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, Examples thereof include dicarboxylic acids such as diglycolic acid, and other polyamides used as mixed components include those composed of these components.

The method for producing nylon 46 used in the present invention is optional. For example, JP-A-56-149430, JP-A-56-149431
JP, JP-A-58-83029 and JP-A-61-43631
For example, a method of preparing a prepolymer having a small number of cyclic end groups under specific conditions and then subjecting it to solid phase polymerization in a steam atmosphere to prepare a high-viscosity nylon 46, or a method disclosed in US Pat. There is a method of obtaining it by heating in a polar organic solvent such as pyrrolidone or N-methylpyrrolidone. The degree of polymerization of nylon 46 is not particularly limited, but the relative viscosity at 30 g and 96% sulfuric acid at 1 g / dl is 2.0.
Nylon 46 in the range of from 6.0 to 6.0 is preferably used.

The modified polyolefin oligomer used in the present invention is a polyolefin oligomer having an ethylene component and / or a propylene component as a main component.
β-unsaturated carboxylic acid or a derivative thereof has a saponification value of 5
It is added in the range of ~ 200mg KOH / g, and the viscosity at 40 ° C is in the range of 100 ~ 50,000 centipoise.

The unmodified polyolefin oligomer as a raw material of the modified polyolefin oligomer contains an ethylene component and / or
Or, if the propylene component is the main component, other components such as butene-1, hexene-1, decene-1,
4-methylbutene-1,4-methylpentene-1, hexadiene, nalbornadiene, butadiene, isoprene, acrylic acid, methacrylic acid, methyl methacrylic acid, sodium acrylate, zinc acrylate, vinyl acetate, glycidyl methacrylate, etc. within 40 mol% May be contained in the molecular chain within the range of

Any polyolefin oligomer may be used as long as the above is satisfied. For example, polyethylene, polypropylene,
Ethylene-propylene copolymer, ethylene-butene-1
Copolymer, ethylene-vinyl acetate copolymer, ethylene-
An oligomer such as an acrylic acid copolymer, an ethylene-ethyl acrylic acid copolymer, and an ethylene-sodium acrylate copolymer can be given. Among them, polyethylene, polypropylene, ethylene-propylene copolymer and ethylene-butene-1 copolymer oligomer are α, β
-Preferred because of easy grafting of unsaturated carboxylic acids.

As the α, β-unsaturated carboxylic acid or its derivative (hereinafter simply referred to as “unsaturated carboxylic acid”) to be grafted onto the unmodified polyolefin oligomer, acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid or anhydrides of these acids are used. And esters of these acids. Of these, maleic anhydride is preferred.

The amount of unsaturated carboxylic acid to be grafted onto the unmodified polyolefin oligomer is such that the saponification value after modification is 5 to 200 mg.
It is adjusted to be in the range of KOH / g. Saponification value 5mg K
If it is less than OH / g, the stabilizing effect during hot melt molding is not significant,
Conversely, the generation of silver streaks may be promoted.
If the saponification value exceeds 200 mg KOH / g, gelation may occur during hot melt molding. Therefore, the preferred saponification value is 5
200 mg KOH / g.

The viscosity of the modified polyolefin oligomer at 40 ° C. must be in the range of 100 to 50,000 centipoise. If the viscosity is less than 100 centipoise, volatilization is likely to occur during molding and odor may be generated. Conversely, if it exceeds 50,000 centipoise, the compatibility with nylon 46 will be poor and the surface gloss will be reduced.

The α, β-unsaturated carboxylic acids may be added to the polyolefin oligomer by adding them in advance as a copolymer during the polymerization of the polyolefin oligomer, or may be grafted by a conventional method after obtaining the polyolefin oligomer. It may be added by conversion.

The amount of the modified polyolefin oligomer is Nylon 46
It is preferable to add 0.1 to 10 parts by weight to 100 parts by weight. If the amount of the modified polyolefin oligomer is less than 0.1 part by weight, the stabilizing effect during hot melt molding is not remarkable,
If the amount is more than the weight part, heat resistance such as heat denaturation temperature may be reduced, or silver streaks may be generated during molding.

The resin composition of the present invention may further contain additives such as a heat stabilizer, an antioxidant, a light stabilizer, a lubricant, a pigment, a flame retardant, and a plasticizer. Further, a fiber reinforcing agent such as glass fiber, metal fiber, potassium titanate whisker, and carbon fiber, and a filler-based reinforcing agent such as talc, calcium carbonate, mica, glass flake, and metal flake may be added. In particular, by adding 10 to 50% by weight of the glass fiber to the resin composition of the present invention, not only the mechanical strength and the heat resistance temperature are significantly improved, but also the improvement effect on the water resistance is recognized. It is preferable to achieve.

(Examples) Examples 1 to 3, Comparative Example 1 Nylon 46 (STANYLKS-400, DSM, The Netherlands) having a relative viscosity of 4.0 and vacuum dried at 100 ° C. for 16 hours in advance, and a copolymerized oligomer of ethylene and propylene with anhydrous maleic anhydride Modified polyolefin oligomer A grafted with acid
(Mitsui Petrochemical Industries Lucant A5202, saponification value 19mg KOH
/ g, a viscosity of 300 centipoise at 40 ° C.) at the ratios shown in Table 1. 300 ° C using a twin screw extruder
And extrusion cut at a temperature of to obtain pellets. In each case, good pellets were obtained.

Injection molding machine (Nikko J100S) using the obtained pellets
The test piece was formed at 300 ° C. Observation of burn streaks entering a molded product was performed in three cases of injection molding cycle time of 20 seconds, 100 seconds, and 200 seconds.

The heat denaturation temperature, toluene swelling degree, flexural strength and flexural modulus of the test piece molded with a cycle time of 20 seconds were measured. The results thus obtained are shown in Table 1.

Examples 4 to 6 Three parts by weight of three kinds of modified polyolefin oligomers B, C, and D were added to 100 parts by weight of nylon 46 having a relative viscosity of 3.5 (STANYLKS-300, DSM, The Netherlands) which had been vacuum-dried at 100 ° C. for 16 hours in advance. And extruded and molded in the same manner as in Examples 1-3. The results are shown in Table 2.

(Effect of the Invention) As shown in Tables 1 and 2, in the resin composition of the present invention, the occurrence of burns during injection molding can be achieved without impairing the excellent heat resistance, chemical resistance and mechanical properties of nylon 46. It is effectively prevented, and the stability during hot melt molding is greatly improved.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-188461 (JP, A) JP-A-60-76557 (JP, A) JP-A-62-179562 (JP, A) JP-A-63-1988 56559 (JP, A)

Claims (1)

(57) [Claims] 1. A polyolefin oligomer having an ethylene component and / or a propylene component as a main component and an α, β-unsaturated carboxylic acid or a derivative thereof having a saponification value of 5 to 200 mg KOH / g, and the viscosity at 40 ° C is 100 to 50,000.
A stabilized resin composition containing 0.1 to 10 parts by weight of a modified polyolefin oligomer having a centipoise range.