JP5451970B2 - Polyamide resin composition pellet blend, molded article, and method for producing pellet blend - Google Patents

Description

 The present invention relates to a novel pellet blend. More specifically, the present invention relates to a pellet blend having excellent surface design and good molding cycle properties while maintaining rigidity and strength.

In general, polyamide resins are widely used for automobile parts, electrical / electronic parts, building materials, household goods, etc. due to their excellent mechanical properties, heat resistance, impact resistance, chemical resistance, and the like. Among them, it is known that a polyamide resin obtained by blending an inorganic filler typified by glass fiber has greatly improved strength, rigidity, and heat resistance.
However, when these inorganic fillers, particularly polyamide resins with a high glass fiber content, are injection molded, the glass fiber is exposed on the surface, causing problems such as greatly impairing the design of the surface, so its use is limited. There were problems such as being.
In order to solve these problems, a method has been proposed in which an amorphous polyamide resin is added to a crystalline polyamide resin and an inorganic filler such as glass fiber is further blended (for example, Patent Documents 1 and 2).
Also blended with inorganic fillers such as glass fiber in polyamide resins with relatively low temperature crystallization temperature such as polyamide resin (hereinafter referred to as polyamide 66 / 6I copolymer) obtained by copolymerization of adipic acid, isophthalic acid and hexamethylenediamine. There has also been proposed a method (Patent Documents 3 and 4).
However, although these methods can provide a relatively good appearance of the molded product, due to the influence of the amorphous polyamide resin or the polyamide resin having a low temperature-falling crystallization temperature, the molding cycle becomes long, which may impair productivity. there were. In addition, the hot strength and creep characteristics are reduced, which may impair the product.

JP 2000-154316 A JP 2000-345032 A Japanese Patent Laid-Open No. 11-71518 JP 2000-178441 A

  The object of the present invention is to eliminate the disadvantages of the conventional polyamide resin as described above, and to provide a pellet blend excellent in both surface design and high cycle property, in particular, without damaging the bending strength and bending elastic modulus. It is to provide a pellet blend excellent in both surface design and high cycle property.

Under such circumstances, the above problems can be achieved by producing a polyamide resin reinforced with an inorganic filler by a specific production method as a result of detailed examination of components and production methods constituting the polyamide resin. I found.
Specifically, it has been found that the above problems can be solved by the following means.
(1) At least a polyamide resin (a) 30 containing a crystalline polyamide resin and / or an amorphous polyamide resin (a-1) having a temperature-falling crystallization temperature (Tc) measured by a differential scanning calorimeter of 210 ° C. or lower. Polyamide resin composition pellets (A) comprising ˜100 wt% and inorganic filler (b) 70˜0 wt%;
Lubricant pellets (B) containing 1 to 30% by weight (in the lubricant pellets) of the lubricant (c) in the polyamide resin (a-3),
Pellet blend containing polyamide resin composition pellets (A) / lubricant pellets (B) = 80 to 99.5 / 20 to 0.5.
(2) The pellet blend according to (1), wherein the content of the inorganic filler (b) in the polyamide resin composition pellet (A) is 15 to 60% by weight.
(3) The pellet blend according to (1) or (2), wherein the lubricant pellet (B) further contains 5 to 50% by weight of the inorganic filler (d) in the lubricant pellet (B).
(4) The polyamide resin (a-1) is a polyamide resin, polyamide 6, polyamide 6I / 6T copolymer and polyamide 66 / 6I obtained from xylylenediamine and an α, ω-linear aliphatic dibasic acid. The pellet blend according to any one of (1) to (3), which is at least one polyamide resin selected from the group consisting of copolymers.
(5) The polyamide resin (a-1) is a polyamide resin, polyamide 6, polyamide 6I / 6T copolymer and polyamide 66 / 6I obtained from xylylenediamine and an α, ω-linear aliphatic dibasic acid. The pellet blend according to any one of (1) to (3), which is at least two types of polyamide resins selected from the group consisting of copolymers.
(6) The polyamide resin (a-1) according to any one of (1) to (3), including at least a polyamide resin obtained from xylylenediamine and an α, ω-linear aliphatic dibasic acid. Pellet blend.
(7) The pellet blend according to any one of (1) to (6), wherein the polyamide resin (a) includes at least polyamide 66 as a polyamide resin (a-2) other than the polyamide resin (a-1). object.
(8) The pellet blend according to any one of (1) to (7), wherein the inorganic filler (b) is at least one selected from the group consisting of glass fiber, mica, talc and wollastonite.
(9) The pellet blend according to any one of (1) to (8), wherein the lubricant (c) is at least one selected from the group consisting of fatty acid metal salts, fatty acid esters, hydrocarbon compounds, and ketone compounds. object.
(10) A molded article using the pellet blend according to any one of (1) to (9).
(11) The molded product according to (10), which is a part of a vehicle or a building material.
(12) A polyamide resin (a) 30 containing at least a crystalline polyamide resin and / or an amorphous polyamide resin (a-1) having a temperature-falling crystallization temperature (Tc) measured by a differential scanning calorimeter of 210 ° C. or lower. ~ 100 wt% and inorganic filler (b) 70 to 0 wt% polyamide resin composition pellets (A), polyamide resin (a-3) 1-30 wt% (c) lubricant (c) ( In a pellet) containing lubricant pellets (B),
Polyamide resin composition pellets (A) / lubricant pellets (B) = 80 to 99.5 / 20 to 0.5.
(13) A polyamide resin (a) 30 containing at least a crystalline polyamide resin and / or an amorphous polyamide resin (a-1) having a temperature-falling crystallization temperature (Tc) measured by a differential scanning calorimeter of 210 ° C. or lower. Polyamide resin composition pellets (A) containing ˜100 wt% and inorganic filler (b) 70˜0 wt%;
Lubricant pellets (B) containing 1-30 wt% (in pellets) of lubricant (c) in polyamide resin (a-3),
Polyamide resin composition pellets (A) / lubricant pellets (B) = A method for improving molding cycle properties of resin composition pellets, comprising mixing at a weight ratio of 80 to 99.5 / 20 to 0.5.

According to the present invention, it is possible to obtain a polyamide resin composition excellent in both surface design and high cycle performance. In particular, it has become possible to obtain a polyamide resin composition having high mechanical strength that enables metal replacement.
Furthermore, after the polyamide resin composition pellets (A) of the present invention and the lubricant pellets (B) containing the lubricant component are separately manufactured, they are pellet-blended so that the lubricant component is directly kneaded. A small amount of lubricant can achieve both high cycle and excellent surface design, which is industrially beneficial.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

Polyamide resin composition pellet (A)
In the present invention, the polyamide resin composition pellet (A) is at least a polyamide resin containing a crystalline polyamide resin (a-1) having a temperature-falling crystallization temperature (Tc) measured by a differential scanning calorimeter of 210 ° C. or lower. It contains 30 to 100% by weight of (a) and 70 to 0% by weight of inorganic filler (b).

Polyamide resin (a)
The polyamide resin (a) used in the present invention is at least a crystalline polyamide resin and / or an amorphous polyamide resin (a-1) having a temperature-falling crystallization temperature (Tc) measured by a differential scanning calorimeter of 210 ° C. or lower. ).

The temperature-falling crystallization temperature in the present invention is the temperature at the peak top of the exothermic peak observed by the differential scanning calorimetry (DSC) method. The exothermic peak is a peak observed when the temperature is lowered after the sample is heated and melted once to eliminate the influence of the thermal history as much as possible. Specifically, it can be obtained in the following manner. The temperature is raised from 30 to 300 ° C. at a rate of 10 ° C./min, and held at 300 ° C. for 2 minutes. Then, the temperature-falling crystallization temperature is obtained from the peak top of the exothermic peak observed when the temperature is lowered to 30 ° C. at a rate of 20 ° C./min. In the present invention, the temperature drop crystallization temperature is 210 ° C. or less means that the temperature drop crystallization temperature measured by DSC is always 210 ° C. or less in the range of relative viscosity of 2.0 to 3.5 described later. say.
As the polyamide resin (a-1), those satisfying the requirement that Tc is 205 ° C. or less are preferable. When the crystallization temperature of the polyamide resin (a-1) exceeds 210 ° C., the molded product obtained has a large surface glass float and a molded product having an excellent appearance cannot be obtained.
The polyamide resin (a-1) preferably satisfies the requirements of a relative viscosity of 2.0 to 3.5 measured in 96% sulfuric acid at a resin concentration of 1 g / 100 ml and a temperature of 25 ° C. When the relative viscosity is less than 2.0, the mechanical strength is lowered, and when it exceeds 3.5, the moldability may be lowered.

Examples of the polyamide resin (a-1) include ε-caprolactam, adipic acid, sebacic acid, dodecanedioic acid, isophthalic acid, terephthalic acid, hexamethylenediamine, tetramethylenediamine, 2-methylpentamethylenediamine, and 2,2. , 4-trimethylhexamethylenediamine, metaxylylenediamine, homopolymers obtained by appropriately combining polyamide-forming monomers such as bis (3-methyl-4-aminocyclohexyl) methane, copolymers alone, homopolymers , A mixture of copolymers, a mixture of a copolymer and a homopolymer, and the like can be used.
Specific examples of the crystalline polyamide resin having a Tc of 210 ° C. or less include polyamide 6, nylon 610, polyamide 612, polyamide 12, polyamide resin obtained by polymerizing xylylenediamine and adipic acid (polyamide MXD6), metaxylylene diene Polyamide resin (polyamide MP6) obtained by polymerizing amine, paraxylenediamine and adipic acid, polyamide 6I obtained by polymerizing hexamethylenediamine and isophthalic acid, isophthalic acid and bis (3-methyl-4-aminocyclohexyl) methane Examples include homopolymers such as polyamide PACM obtained by polymerization, and polyamide 66 / 6I copolymers obtained by polymerizing adipic acid, isophthalic acid, and hexamethylene diamine, but the present invention is not limited thereto. Polyamide 6, polyamide MXD6, polyamide 66 / 6I copolymer, polyamide 66 / 6I copolymer, and polyamide MP6 are preferable.
These polyamide resins may be used alone or in combination of two or more.

  Specific examples of the amorphous polyamide resin include polyamide TMDT obtained by polymerizing terephthalic acid and 2,2,4-trimethylhexamethylenediamine, and polyamide 6I / 6T obtained by polymerizing isophthalic acid, terephthalic acid and hexamethylenediamine. Copolymer, copolymer of metaxylylenediamine terephthalate and / or isophthalate and ε-caprolactam, ε-caprolactam polymerized to hexamethylenediamine terephthalate and / or isophthalate However, the copolymer is not particularly limited. Polyamide 6I / 6T copolymer is preferable.

The polyamide resin composition pellet (A) may contain a polyamide resin (a-2) other than the polyamide resin (a-1). Such a polyamide resin (a-2) preferably satisfies the condition that Tc is 220 ° C. or higher. For example, polyamide 46 obtained by copolymerizing 1,4-diaminobutane and adipic acid, hexamethylenediamine and adipine Examples thereof include polyamide 66 obtained by polymerizing an acid and blends thereof. By using a small amount of a polyamide resin having a Tc of 220 ° C. or higher, the crystallization speed can be improved, and the releasability and molding cycle can be improved.
When the polyamide resin (a-2) is used, the ratio of the polyamide resin (a-1) to the polyamide resin (a-2) is preferably (a-1) / (a-2) = 50 to 95. / 50 to 5 (weight ratio), more preferably 75 to 92.5 / 25 to 7.5 (weight ratio). By setting it as such a compounding ratio, mold release property and a molding cycle are improved effectively, and there exists a tendency for an external appearance to become more favorable.

(B) Inorganic filler As the inorganic filler (b) in the present invention, a known inorganic filler can be used, and the shape is not particularly limited, and is fibrous, plate-like, needle-like, spherical, powder, etc. Any shape may be sufficient. The types of inorganic fillers are glass fiber, carbon fiber, talc, mica, glass flake, wollastonite, potassium titanate, magnesium sulfate, sepiolite, zonolite, aluminum borate, glass beads, balloon, carbonic acid. Calcium, silica, kaolin, clay, carbon black, titanium oxide, barium sulfate, zinc oxide, magnesium hydroxide and the like can be mentioned, and these can be used alone or as a mixture of two or more. The inorganic filler is preferably glass fiber, mica, talc, or wollastonite because it is excellent in the balance of mechanical strength, rigidity, and surface appearance and is easily available.

  The glass fiber is not particularly limited as long as it is generally used for resin reinforcement. For example, the glass fiber can be selected from a long fiber type (roving), a short fiber type (chopped strand), and the average fiber diameter. Is generally 6 to 15 μm. Moreover, especially average fiber length is although it does not restrict | limit, 0.1-20 mm is preferable and 1-10 mm is more preferable. As mica, talc, and wollastonite, there is no restriction on the particle diameter, and any one can be used. For example, the particle diameter is preferably 1 to 80 μm, more preferably 5 to 50 μm. By using such an inorganic filler, the reinforcing effect by the inorganic filler is more effectively expressed, and a molded product having excellent surface design and dimensional stability can be obtained.

These inorganic fillers may be surface-treated with a sizing agent and / or a surface treatment agent if necessary from the viewpoint of handling and adhesion to the resin. Examples of sizing agents and / or surface treatment agents include silane compounds such as γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, epoxy compounds, and isocyanates. It is possible to use a known sizing agent or surface treatment agent such as a system compound or a titanate compound. The adhesion amount of these sizing agent and / or surface treatment agent is preferably 0.01% by weight or more, more preferably 0.05% by weight or more of the weight of the inorganic filler (b). The upper limit is not particularly defined, but can be, for example, 1% by weight or less.
Furthermore, if necessary, a lubricant such as a fatty acid amide compound, silicone oil, an antistatic agent such as a quaternary ammonium salt, a resin having a film forming ability such as an epoxy resin or a urethane resin, a resin having a film forming ability and a heat What was surface-treated with what used a stabilizer, a flame retardant, etc. together can also be used.
The inorganic filler (b) employed in the present invention may be used after subjecting to a sizing treatment or a surface treatment in advance using the sizing agent and / or surface treatment agent, or at the time of producing the polyamide resin composition pellet (A). You may add simultaneously with an untreated inorganic filler.

  The compounding ratio of the polyamide resin (a) and the inorganic filler (b) in the polyamide resin composition pellet (A) of the present invention is as follows: polyamide resin (a) / inorganic filler (b) = 30-100 / 70- 0 (weight ratio). If the amount of the inorganic filler exceeds the upper limit, the processability is inferior. A more preferable blending ratio is polyamide resin (a) / inorganic filler (b) = 40 to 85/60 to 15 (weight ratio), and more preferably polyamide resin (a) / inorganic filler (b) = 35 to 80/65 to 20 (weight ratio).

(B) Lubricant pellet In the present invention, the lubricant pellet (B) is a necessary component for achieving the present invention. That is, the lubricant pellet (B) is a lubricant master batch containing 1 to 30% by weight of the polyamide resin (a-3) and at least one lubricant (c) in the pellet. By using the lubricant as a master batch pellet, the releasability at the time of molding is improved, and the surface design of the resulting molded product is excellent. Moreover, the cooling time at the time of molding can be shortened, and the molding cycle performance is improved.
Usually, when producing resin composition pellets using a vented extruder, the lubricant evaporates from the vents and strands during melt kneading, and the lubricant content in the resin composition pellets used for molding decreases, Problems such as gas generation may occur during the production of resin composition pellets. However, as in the present invention, by using a lubricant as a lubricant pellet for molding, transpiration of the lubricant component as described above and resin composition pellet production are possible. Generation | occurrence | production of the malfunction inside can be avoided and the lubricant in a resin composition can be maintained at a desired density | concentration. In addition, by adding lubricant as a lubricant pellet, the lubricant component tends to be unevenly distributed on the surface of the molded product during molding, so the concentration of the lubricant on the surface of the molded product is increased, improving mold release and molding cycle performance instead of the amount added. It is thought that the effect becomes high.
As a polyamide resin (a-3) used for a lubricant pellet (B), the kind is not stipulated in particular, and even if the kind is the same as the polyamide resin (a) used in a polyamide resin composition pellet (A). It may be good or different.
In the present invention, the polyamide resin (a-3) used for the lubricant pellet (B) preferably contains a resin selected from the polyamide resin (a). From the viewpoint of compatibility, the polyamide resin composition pellet (A It is more preferable that the same polyamide resin as that contained in the polyamide resin (a) is included, and it is more preferable that the same polyamide resin as that contained in the polyamide resin composition pellet (A) is contained in an amount of 10% by weight or more. The polyamide resin (a) contained in the polyamide resin pellet (A) is particularly preferably the same.

(C) Lubricant The lubricant (c) used in the present invention includes, for example, an aliphatic carboxylic acid metal salt, an aliphatic carboxylic acid ester, an aliphatic carboxylic acid, a hydrocarbon compound, paraffin wax, a ketone compound, and a carboxylic acid amide. Among them, aliphatic carboxylic acid metal salts, aliphatic carboxylic acid esters, hydrocarbon compounds, and ketone compounds are preferable, and aliphatic carboxylic acid metal salts and aliphatic carboxylic acid esters are more preferable. .
The aliphatic carboxylic acid metal salt is preferably a metal salt of a higher fatty acid having 16 to 36 carbon atoms, such as magnesium stearate, calcium stearate, barium stearate, calcium montanate, sodium montanate, zinc stearate, stearin. Examples thereof include aluminum oxide, sodium stearate, and lithium stearate.
The aliphatic carboxylic acid ester is a compound composed of an aliphatic carboxylic acid and an alcohol, such as beeswax, lanolin, stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate. Examples thereof include rate, glycerol distearate, glycerol tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate.
The content of the lubricant (c) in the lubricant pellet (B) is 1 to 30% by weight, preferably 5 to 15% by weight. If it is less than 1% by weight, the effect of improving the molding cycle when blended is small, and if it exceeds 30% by weight, it becomes difficult to produce the lubricant pellets (B), or gas is increased when blended and molded. Cause a malfunction.

(D) Inorganic filler In addition to the lubricant (c), an inorganic filler (d) may be added in advance to the lubricant pellet (B) for the purpose of not reducing the strength and productivity of the molded product. . As an inorganic filler (d), what was mentioned, for example with the inorganic filler (b) used for the said polyamide resin composition pellet (A) is mentioned, You may use together 2 or more types. Of these, glass fiber and talc are preferred because they have an excellent balance of mechanical strength, rigidity, and surface appearance, and are easily available, and glass fibers are preferred because they have better mechanical strength, molding cycle performance, surface appearance, and weather resistance. It is more preferable to use talc in combination.
The content of the inorganic filler (d) is preferably 5 to 50% by weight in the lubricant pellet (B), and more preferably 15 to 45% by weight. By setting it as such content, surface appearance becomes more favorable and is preferable.

As a manufacturing method of a polyamide resin composition pellet (A) and a lubricant pellet (B), a normal method can be employ | adopted and there is no restriction | limiting in particular. Examples thereof include a melt kneading method using a conventional apparatus such as a single-screw or multi-screw extruder, preferably a vent-type extruder or a similar apparatus. The vent type extruder removes gas (air and moisture) contained in the resin composition, improves the adhesion between inorganic fillers such as glass fiber and mica and resin, and when molding oligomers, etc. There is an effect of removing a component that causes the occurrence of a malfunction. In this invention, it is preferable to make the moisture content in a resin composition pellet into 0.2 weight% or less using a vent type extruder. By setting it as such a moisture content, it becomes the tendency which suppresses mold contamination by the gas generation at the time of shaping | molding, and it becomes easier to obtain the molded article of the outstanding external appearance.
The blend amount of the polyamide resin composition pellets (A) and the lubricant pellets (B) is (A) / (B) = 80 to 99.5 / 20 to 0.5 by weight ratio, preferably 85 to 99 / 15 to 1, more preferably 90 to 98.8 / 10 to 1.2. If the blend amount of the lubricant pellets (B) in the pellet blend of the present invention is less than 0.5% by weight, the effect for improving the molding cycle is small, and if it exceeds 20% by weight, the gas during molding increases, which is not preferable.

In the pellet blend of the present invention, the content of the lubricant (c) in the pellet blend is preferably 0.01 to 2% by weight, more preferably 0.05 to 1% by weight. By setting the content of the lubricant (c) within the above range, gas generation during molding, transfer unevenness of the molded product, and generation of silver tend to be more easily suppressed.
In the present invention, the content of the inorganic filler (total amount of (b) and (d)) in the pellet blend is preferably 20 to 70% by weight, and 30 to 65% by weight. It is more preferable. When the total content of the inorganic filler is 20% by weight or more, the mechanical strength tends to be higher, and when it is 70% by weight or less, the production of pellets tends to be easier, The surface design tends to be improved. For example, when the content of the inorganic filler (b) in the polyamide resin composition pellet (A) is 15 to 60% by weight, the content of the inorganic filler (d) in the lubricant pellet (B) is: The content of the inorganic filler (b) in the polyamide resin composition pellets (A) is preferably 40 to 60% by weight, preferably 15 to 45% by weight in the pellets (B). It is more preferable that the content of the inorganic filler (d) in (B) is 20 to 40% by weight in the pellet (B).

The resin composition pellets (A) and lubricant pellets (B) used in the present invention may be blended with known resin additives and the like as necessary in addition to the above components within the scope of the present invention. it can. Examples of additives include dyes and pigments, antioxidants, heat stabilizers, mold release agents, ultraviolet absorbers, antistatic agents, color tone improvers, foaming agents, plasticizers, nucleating agents, impact resistance improvers, and the like. It is done. These other additives can be used alone or in combination.
Furthermore, the resin composition pellet (A) and the lubricant pellet (B) used in the present invention contain a resin other than the polyamide resin as a part of the resin component, as long as the effect of the present invention is not impaired, as necessary. May be. Examples of the thermoplastic resin that can be blended include polyphenylene ether resin, acrylic resin, polyester resin, polyphenylene sulfide resin, liquid crystal polyester resin, and polyacetal resin. Examples of thermosetting resins that can be blended include phenol resins, melamine resins, silicone resins, and epoxy resins. When the resin other than the polyamide resin is included, the amount of the other resin is preferably 50% of the total weight of the polyamide resin (a) and the polyamide resin (a-3) in the pellet blend of the present invention. % Or less, more preferably 30% by weight or less.

The method for producing the polyamide resin composition pellets (A) of the present invention is not particularly limited, and usually the polyamide resin (a) and the inorganic filler (b) and other components to be blended as necessary are provided. It is manufactured by melt-kneading after quantitative blending and cutting into pellets.
The melt kneading method may be any known method. For example, using a single-screw or twin-screw extruder, a Banbury mixer, or a similar device, all the materials may be charged all at once from the root of the extruder and melt kneaded. ) And other components added as necessary, and a method of side-feeding and kneading the inorganic filler (b) while melting it may be used. The lubricant pellet (B) can also be produced using the same method as the polyamide resin composition pellet (A). For example, the polyamide resin (a-3), the lubricant (b), and other components blended as necessary may be put into an extruder at a time and melt-kneaded, or the inorganic filler (d) may be blended. In this case, the inorganic filler (d) may be side-feeded and melt-kneaded.
When melt-kneading using an extruder, the molten resin composition is extruded from a die as 1 to several tens of strands in an extruder, solidified by cooling in a cooling water tank or in air, and cut with a strand cutter. Into pellets. The pellets produced in this way usually have an elliptical columnar shape or a cylindrical shape. The pellet preferably has a pellet length of 1 to 5 mm, more preferably 2 to 4 mm. When the cross section is elliptical, the major axis is 2 to 3.5 mm, the minor axis is 1 to 2.5 mm, and the section is When is circular, a diameter of 2 to 3 mm is preferable. The length and cross-sectional shape of the pellet can be adjusted by the number of rotations of the blade of the strand cutter, the winding speed, and the discharge amount of the extruder. Moreover, it is preferable to approximate the shape and size of the polyamide resin composition pellet (A) and the lubricant pellet (B) as much as possible. By using the above pellets, when the blend of the polyamide resin composition (A) and the lubricant pellet (B) is used for molding, classification in the molding process is prevented, generation of unmelted material and air entrainment Can be obtained, and a molded product excellent in mechanical strength and surface design can be obtained.

As a method for producing the pellet blend of the present invention, a usual method can be adopted, and there is no particular limitation. For example, the polyamide resin composition pellets (A) obtained by the above method are post-blended with the lubricant pellets (B) obtained by the above method using a weight feeder, or a stirring device such as a tumbler is used. And a method of blending the polyamide resin composition pellets (A) and the lubricant pellets (B).
The pellet blend of the present invention thus obtained can be molded by a molding method generally used for thermoplastic resin compositions, but injection molding is preferred from the viewpoint of fluidity.

  The molded article obtained by using the pellet blend of the present invention has excellent mechanical strength and good molding cycleability, and the molded article comprising the molded article is excellent in surface design. It is useful as a part of As a vehicle, it is suitable for exterior and interior parts of a vehicle such as a door mirror stay, an inner mirror stay, a door handle, a door mirror bracket, a roof rail, and a wiper arm. Moreover, as a building material, it is suitable for a crescent, a door handle knob, a French drop, etc.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

The raw materials used in the examples and comparative examples are as follows.
(1) Polyamide resin 1: Poly (metaxylylene adipamide) (hereinafter referred to as “polyamide MXD6”), manufactured by Mitsubishi Gas Chemical Co., Ltd., relative viscosity (measured at a temperature of 25 ° C. using 98% sulfuric acid as a solvent) 2.14, temperature drop crystallization temperature 205 ° C
(2) Polyamide resin 2: Polyamide 66, manufactured by Toray Industries, Inc., trade name Amilan CM3001-N, relative viscosity 2.95 (measured in the same manner as in the above (1)), cooling crystallization temperature 225 ° C.
(3) Polyamide resin 3: Polyamide 6, manufactured by Mitsubishi Engineering Plastics Co., Ltd., trade name Novamid (registered trademark) 1007J, relative viscosity 2.20 (measured by the same method as in (1) above), temperature-falling crystallization 180 ° C
(4) Polyamide resin 4: Polyamide 6I / 6T copolymer, manufactured by Mitsubishi Engineering Plastics Co., Ltd., trade name Novamid (registered trademark) X21, relative viscosity 2.80 (measured in the same manner as in (1) above) .)
(5) Polyamide resin 5: Polyamide 66 / 6I copolymer, relative viscosity 2.30 (measured by the same method as in (1) above), temperature drop crystallization temperature 198 ° C.
[Production Method of Polyamide Resin 5]
2.0 kg of equimolar salt of adipic acid and hexamethylenediamine, 0.5 kg of equimolar salt of isophthalic acid and hexamethylenediamine, and 2.5 kg of pure water were charged into a 5-liter autoclave and stirred well while purging with nitrogen. . Next, the temperature was raised from around room temperature to 220 ° C. for about 1 hour with stirring. Thereafter, the temperature was raised to 260 ° C. in about 2 hours while removing water from the reaction system so that the internal pressure of the autoclave became 18 kg / cm ² -G. Thereafter, the heating was stopped, the autoclave was sealed, and it took about 8 hours to cool to around room temperature, to obtain about 2 kg of polyamide 66 / 6I (composition weight ratio: 78.5 / 21.5) polymer. The obtained polymer was pulverized, and the molecular weight was increased by solid phase polymerization at 200 ° C. for 10 hours under a nitrogen atmosphere using a 10 liter evaporator to obtain a polymer having a relative viscosity of 2.30.
(6) Glass fiber: Chopped strand, manufactured by Asahi Fiber Glass Co., Ltd., trade name CS03-JAFT2, average fiber length 3 mm, average fiber diameter 10 μm
(7) Mica: Suzolite mica, manufactured by Kuraray Trading Co., Ltd., trade name 325HK, weight average particle size 20 μm
(8) Talc 1: Hayashi Kasei Co., Ltd., trade name Micron White 5000A, weight average particle size 4.7 μm
(9) Talc 2: manufactured by Fuji Talc Co., Ltd., trade name TM-2, weight average particle size 14.3 μm
(10) Wollastonite: manufactured by Naiko Co., Ltd., trade name Nigros 8, weight average particle size 8 μm
(11) Carbon black 1: manufactured by Mitsubishi Chemical Corporation, # 45, weight average particle size 24 μm
(12) Carbon black 2: manufactured by Mitsubishi Chemical Corporation, # 960, weight average particle diameter 16 μm
(13) Lubricant 1: Barium stearate, manufactured by Sakai Chemical Co., Ltd. (14) Lubricant 2: Montanic acid ester, manufactured by Clariant, trade name Ricowax E
(15) Lubricant 3: Sodium montanate, manufactured by Clariant, trade name Recommont NAV101
(16) Lubricant 4: Carboxylic acid amide wax, manufactured by Kyodo Yushi Co., Ltd., trade name LIGHT AMIDE WH255
(17) Lubricant 5: stearyl stearate, manufactured by Riken Vitamin Co., Ltd., trade name SL-900A
(18) Lubricant 6: Ketone wax, manufactured by Cognis Japan, trade name Roxyol EP2036-18
(19) Lubricant 7: polyethylene wax, manufactured by Mitsui Chemicals, trade name High Wax 405MP
(20) Lubricant pellet 1: polyamide resin 1 / polyamide resin 2 / talc 1 / lubricant 1 = 60/10/20/10 blended in weight (weight ratio), mixed with tumbler for 20 minutes, vented After melt-kneading at 270 ° C. using a type extruder (Toshiba Machine Co., Ltd., TEM37BS), extruding into a string shape, cooling in a water bath, cutting and drying to form an elliptical column shape, 3 to 3.5 mm long pellets Manufactured.
(21) Lubricant pellet 2: Polyamide resin 1 / polyamide resin 2 / talc 1 / glass fiber / lubricant 1 = weighed in a blending amount (weight ratio) of 40/10/20/20/10, other than glass fiber After mixing each component with a tumbler for 20 minutes, it is put into a popper at once, glass fibers are supplied by a side feed method, melt-kneaded at 270 ° C. using a vent-type extruder (TEM 37BS, manufactured by Toshiba Machine Co.), The product was extruded into a shape, cooled in a water tank, cut and dried to produce an elliptical columnar pellet having a length of 3 to 3.5 mm.
(22) Lubricant pellet 3: Polyamide resin 1 / polyamide resin 2 / talc 1 / glass fiber / lubricant 2 / lubricant 3 = 50/5/10/30 / 2.5 / 2.5 (weight ratio) Then, pellets were produced in the same manner as (21) Lubricant pellet 2.
(23) Lubricant pellet 4: Polyamide resin 1 / polyamide resin 2 / talc 1 / glass fiber / lubricant 6 = 50/5/10/30/5 (weight ratio), (21) Lubricant pellet 2 Pellets were produced in the same manner as above.
(24) Lubricant pellet 5: Polyamide resin 1 / polyamide resin 2 / talc 1 / glass fiber / lubricant 7 = 50/5/10/30/5 (weight ratio), (21) Lubricant pellet 2 Pellets were produced in the same manner as above.

In Examples and Comparative Examples, bending characteristics, surface design properties, and high cycle property tests were performed as follows.
(25) Bending characteristics Using an injection molding machine (FANUC, α100iA), primary injection pressure 700 kgf / cm ² , injection speed 50 mm / s, holding pressure 500 kgf / cm ² , injection time 1 second, molding temperature 270 ° C., gold The mold temperature was set to the temperature described in Tables 1 and 2 according to the glass transition temperature of the composition, and a test piece was produced. The bending strength and the flexural modulus were evaluated according to the ISO-178 standard.

(26) Surface design properties Using an injection molding machine (FANUC, α100iA), injection primary pressure 800 kgf / cm ² , injection speed 50 mm / s, holding pressure 500 kgf / cm ² , injection time 2 seconds, molding temperature 270 ° C., The mold temperature was set to the temperatures shown in Tables 1 and 2 according to the glass transition temperature of the composition, the cooling time was 15 seconds, and a 180 mm × 120 mm × 2 mmt flat plate was molded. The surface design after molding was observed with the naked eye. Unevenness due to visual observation of the floating state of the inorganic filler, undulations on the surface of the molded product, and mold release defects
◎: No lifting of inorganic filler, undulation of molded product surface, uneven mold release is observed over the entire surface ○: Lift of inorganic filler, undulation of molded product surface, uneven release over the entire surface is observed slightly Is a level at which there is no problem as an actual molded product.

(27) High cycle property Using an injection molding machine (FANUC, α100iA), injection primary pressure 600 kgf / cm ² , injection speed 50 mm / s, holding pressure 450 kgf / cm ² , injection time 0.5 seconds, molding temperature 270 C. and mold temperature were set to the temperatures shown in Tables 1 and 2 according to the glass transition temperature of the composition, and an ASTM test piece for compression test having a length of 50 mm and a thickness of 12.8 mm was molded.
Evaluation of high cycle performance was performed by measuring the shortest cooling time (necessary cooling time) in which continuous molding was possible when molding was performed five times continuously with a certain cooling time and the cooling time was reduced by 1 second. Further, the releasability during continuous molding with the necessary cooling time was judged according to the following criteria.
◎: No trace of protruding pin on the test piece and good releasability ○: Trace of the protruding pin remains on the test piece, but there is no hindrance to release △: Trace of the protruding pin on the test piece Or the test piece tends to remain in the fixed mold. ×: The test piece is pierced or greatly deformed by the ejector pin, or the test piece is not released from the mold. Specimens remain in the mold

[Examples 1 to 13]
Polyamide resins 1 to 5 and inorganic fillers other than glass fibers are weighed in the amounts shown in Tables 1 and 2 and mixed with a tumbler and then charged into a hopper. Glass fibers are fed by a side feed method and vented. After melt-kneading at 280 ° C. using an extruder (Toshiki Machine Co., Ltd., TEM37BS), extruding into a string shape, cooling in a water bath, cutting, elliptical column shape, 3-3.5 mm long polyamide resin composition pellets (A) was obtained.
In the subsequent process, any one of the lubricant pellets 1 to 3 was post-blended with the previously obtained pellet (A) with another feeder, and dried to obtain a pellet blend. Using the obtained pellet blend, a test piece was prepared by the method described above and evaluated. The evaluation results are shown in Tables 1 and 2.
In any of the pellet blends, while maintaining high strength, there was little or no unevenness of the surface of the inorganic filler and release, and the surface design was excellent. In addition, the required cooling time was short, the releasability was good, and the high cycle property was excellent.

[Comparative Examples 1-8]
Polyamide resins 1 to 5, inorganic fillers other than glass fibers, lubricants 1, 4 or 5 are weighed, mixed with a tumbler and then charged into a hopper. Glass fibers are fed by a side feed method, and a vent type extruder. (Toshiba Machine Co., Ltd., TEM37BS) was melt-kneaded at 280 ° C., extruded into a string shape, cooled in a water tank, cut and dried to obtain an elliptical columnar pellet having a length of 3 to 3.5 mm. Using the obtained pellets, test pieces were prepared by the method described above and evaluated. The evaluation results are shown in Tables 1 and 2.
Compared to the examples in which the lubricant pellets were post-blended, the required cooling time was long and the molding cycle was long, and the releasability was inferior.
In Comparative Examples 5 to 8, in particular, since the solidification of the surface was slow, the releasability was greatly reduced, and the product could not be used as an industrial product. Further, since the releasability is insufficient, surface transfer unevenness may occur, and there may be a problem in design properties.
Furthermore, as is clear from comparison between Example 1 and Comparative Example 1, and Example 6 and Comparative Example 5, even when the lubricant content is the same, the high cycle performance is remarkably improved by employing the pellet blend of the present invention. Confirmed to do.

Examples 1 to 5 are reference examples.

Example 11 is a reference example.

  According to the present invention, it is possible to obtain a polyamide resin composition excellent in all of mechanical strength, surface design properties and high cycle properties. Since the molded article made of the polyamide resin composition of the present invention is excellent in surface design, it is particularly useful as a vehicle exterior and interior part and a building material part.

Claims (7)

A polyamide resin composition pellet (A) comprising at least 40 to 85 % by weight of a polyamide resin (a) containing a polyamide 6I / 6T copolymer and 15 to 60 % by weight of an inorganic filler (b) and a polyamide resin ( a-3) Lubricant (c) 1-30 wt% (in a lubricant pellet) and an inorganic filler (d) 5-50 wt% (in a lubricant pellet), a lubricant pellet (B), a polyamide resin Composition pellet (A) / lubricant pellet (B) = a pellet blend comprising 80 to 99.5 / 20 to 0.5 in a weight ratio. The pellet blend according to claim 1, wherein the inorganic filler (b) is at least one selected from the group consisting of glass fiber, mica, talc and wollastonite. The pellet blend according to claim 1 or 2 , wherein the lubricant (c) is at least one selected from the group consisting of an aliphatic carboxylic acid metal salt, an aliphatic carboxylic acid ester, a hydrocarbon compound and a ketone compound. The molded article using the pellet blend of any one of Claims 1-3 . The molded article according to claim 4 , which is a part of a vehicle or a building material. A polyamide resin composition pellet (A) comprising at least 40 to 85 % by weight of a polyamide resin (a) containing a polyamide 6I / 6T copolymer and 15 to 60 % by weight of an inorganic filler (b);
Lubricant pellets (B) containing 1 to 30% by weight (in pellets) of lubricant (c ) and 5 to 50% by weight (in pellets) of inorganic filler (d) in polyamide resin (a-3),
Polyamide resin composition pellets (A) / lubricant pellets (B) = 80 to 99.5 / 20 to 0.5. A polyamide resin composition pellet (A) comprising at least 40 to 85 % by weight of a polyamide resin (a) containing a polyamide 6I / 6T copolymer and 15 to 60 % by weight of an inorganic filler (b);
Lubricant pellets (B) containing 1 to 30% by weight (in pellets) of lubricant (c ) and 5 to 50% by weight (in pellets) of inorganic filler (d) in polyamide resin (a-3),
Polyamide resin composition pellets (A) / lubricant pellets (B) = Mixing at a weight ratio of 80 to 99.5 / 20 to 0.5.