JP2021181579A - Molding and method for producing molding - Google Patents

Abstract

To provide a molding that does not allow moisture permeation and has excellent mechanical strength.SOLUTION: A molding is molded from a polyamide resin composition that has a semi-aromatic polyamide resin, and a fiber with a number average fiber length of more than 300 μm, wherein, in the semi-aromatic polyamide resin, a terminal carboxyl group concentration is higher than a terminal amino group concentration, and the difference between the terminal carboxyl group concentration and the terminal amino group concentration is 47 μeq./g or more and less than 100 μeq./g. After the polyamide resin composition molded 1 mm in thickness is let stand at 40°C and 90% RH for 42 hours, the moisture permeability is 3.0 g mm/day m2 or less. The fiber has a number average fiber length of 1.0 mm-6.0 mm. The molding is a camera part.SELECTED DRAWING: None

Description

The present invention relates to a molded product and a method for manufacturing a molded product. In particular, the present invention relates to a molded product suitable for a camera component mounted on an automobile and a method for manufacturing the molded product.

Polyamide resin, which is a typical engineering plastic, is easy to process and is excellent in mechanical physical properties, electrical properties, heat resistance, and other physical and chemical properties. Therefore, it is widely used for vehicle parts, electrical and electronic equipment parts, other precision equipment parts, and the like.
For example, Patent Document 1 contains a dicarboxylic acid unit containing 60 to 100 mol% of a terephthalic acid unit and 60 to 100 mol% of a 1,9-diaminononane unit and / or a 2-methyl-1,8-diaminooctane unit. Polyamide (A) having a diamine unit and a fibrous reinforcing material (B) are melt-kneaded, and the content of the polyamide (A) is 50 to 80% by mass, and the content of the fibrous reinforcing material (B). A barrel or holder of a camera module formed by molding a polyamide composition having a weight of 20 to 50% by mass, and the average length of the fibrous reinforcing material (B) before melt-kneading is 300 μm or less. The barrel or holder is disclosed.

Japanese Unexamined Patent Publication No. 2010-286544

When the present inventor examined the above-mentioned Patent Document 1, it was found that the above-mentioned Patent Document 1 contains a fibrous filler, but its mechanical strength is insufficient. Further, in precision machine parts such as camera parts, it is also required that moisture does not easily permeate. An object of the present invention is to solve such a problem, and an object of the present invention is to provide a molded product having excellent mechanical strength and which is difficult for moisture to permeate.

As a result of the study by the present inventor based on the above problems, a semi-aromatic polyamide resin having a terminal carboxyl group concentration higher than the terminal amino group concentration is used, and the resin is molded from a fiber having a number average fiber length of more than 300 μm. We have found that the adhesiveness between the semi-aromatic polyamide resin and the fiber can be improved, the mechanical strength can be improved, and the moisture can be made difficult to permeate, and the present invention has been completed. ..
Specifically, the above problems were solved by the following means <1>, preferably <2> to <15>.
<1> Molded from a polyamide resin composition containing a semi-aromatic polyamide resin and fibers having a number average fiber length of more than 300 μm, and the terminal carboxyl group concentration of the semi-aromatic polyamide resin is higher than the terminal amino group concentration. Molding.
<2> The molded product according to <1>, wherein the fiber is at least one selected from carbon fiber and glass fiber.
<3> The molded product according to <1> or <2>, wherein the fiber is treated with at least one of a surface treatment agent and a sizing agent.
<4> The molded product according to any one of <1> to <3>, wherein the number average fiber length of the fibers is 1.0 mm to 6.0 mm.
<5> The molded product according to any one of <1> to <4>, wherein the difference between the terminal carboxyl group concentration and the terminal amino group concentration is 40 to 100 μe equivalent / g.
<6> The semi-aromatic polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 70 mol% or more of the diamine-derived structural unit is derived from xylylene diamine and is a dicarboxylic acid-derived constitution. The molded product according to any one of <1> to <5>, wherein 70 mol% or more of the unit is derived from α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms.
<7> The semi-aromatic polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 70 mol% or more of the diamine-derived structural unit is derived from xylylenediamine and is a dicarboxylic acid-derived constitution. The molded product according to any one of <1> to <5>, wherein 70 mol% or more of the unit is derived from adipic acid.
<8> The molded product according to any one of <1> to <7>, further containing a black colorant.
<9> The molded product according to any one of <1> to <8>, further containing talc.
<10> Further, it contains a black colorant and talc, and the mass ratio of the black colorant to the talc (black colorant / talc) in the molded product is 1.5 to 2.5, <1> to <7. > The molded product according to any one of.
<11> The molded product according to any one of <1> to <10>, which is an injection molded product.
<12> The molded product according to any one of <1> to <11>, which is a camera component.
<13> The molded product according to <12>, wherein the maximum length of the camera component is 15 to 40 mm.
<14> The molded product according to <12> or <13>, wherein the camera component contains a member derived from the polyamide resin composition, and the proportion of the member is 1 to 99% by mass.
<15> Injection molding is performed on a polyamide resin composition containing a semi-aromatic polyamide resin and fibers having a number average fiber length of more than 300 μm, and the terminal carboxyl group concentration of the semi-aromatic polyamide resin is higher than the terminal amino group concentration. The method for producing a molded product according to any one of <1> to <14>, which comprises the above.

INDUSTRIAL APPLICABILITY According to the present invention, it has become possible to provide a molded product having excellent mechanical strength and which is difficult for moisture to permeate.

It is a schematic diagram which shows the measuring apparatus of the moisture permeability coefficient.

Hereinafter, the contents of the present invention will be described in detail. In addition, in this specification, "~" is used in the sense that the numerical values described before and after it are included as the lower limit value and the upper limit value.

The molded product of the present invention contains a semi-aromatic polyamide resin and fibers having a number average fiber length of more than 300 μm, and the terminal carboxyl group concentration of the semi-aromatic polyamide resin is higher than the terminal amino group concentration. It is characterized by being a molded product molded from.
By using a semi-aromatic polyamide resin having a terminal carboxyl group concentration higher than the terminal amino group concentration and using a fiber having a number average fiber length of more than 300 μm, the adhesion of the semi-aromatic polyamide resin to the fiber is improved. A molded product with high mechanical strength can be obtained. Further, a molded product in which moisture does not easily permeate can be obtained.

<Semi-aromatic polyamide resin>
The molded article of the present invention contains a semi-aromatic polyamide resin.
Here, the semi-aromatic polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 30 to 70 mol% of the total structural unit of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit is 30 to 70 mol%. It means that it is a structural unit containing an aromatic ring, and it is preferable that 40 to 60 mol% of the total structural unit of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit is the structural unit containing an aromatic ring.

The semi-aromatic polyamide resin used in the present invention has a terminal carboxyl group concentration higher than that of the terminal amino group concentration. With such a configuration, the adhesion between the fiber and the semi-aromatic polyamide resin can be improved.
The difference between the terminal carboxyl group concentration and the terminal amino group concentration in the present invention is preferably 40 to 100 μe equivalent / g. By setting it in such a range, the adhesion with the fiber can be further improved.
The lower limit of the difference between the terminal carboxyl group concentration and the terminal amino group concentration is preferably 45 μe equivalent / g or more, and more preferably 47 μe equivalent / g or more. The upper limit of the difference between the terminal carboxyl group concentration and the terminal amino group concentration is preferably 90 μe equivalent / g or less, more preferably 80 μe equivalent / g or less, and 70 μe equivalent / g or less. It is even more preferably 65 μe equivalent / g or less, and even more preferably 55 μe equivalent / g or less.
The semi-aromatic polyamide resin used in the present invention has a terminal amino group concentration ([NH ₂ ]) of preferably less than 100 μe / g, more preferably 5 to 75 μe / g, and even more preferably 10 to 60 μe / g. g, more preferably 20-50 μe / g. The semi-aromatic polyamide resin used in the present invention has a terminal carboxyl group concentration ([COOH]) of preferably less than 150 μe / g, more preferably 20 to 120 μe / g, and even more preferably 40 to 110 μe / g. g, more preferably 50-100 μe / g, even more preferably 75-100 μe / g.
Further, the ratio of the terminal amino group concentration to the terminal carboxyl group concentration ([NH ₂ ] / [COOH]) is preferably 0.7 or less, more preferably 0.6 or less, still more preferably 0.5 or less. If the ratio is larger than 0.7, it may be difficult to control the molecular weight when polymerizing the semi-aromatic polyamide resin. The lower limit of the ratio of the terminal amino group concentration to the terminal carboxyl group concentration ([NH ₂ ] / [COOH]) is not particularly specified, but may be, for example, 0.2 or more.
The measurement of the terminal amino group concentration and the terminal carboxyl group concentration of the semi-aromatic polyamide resin follows the method described in Examples described later. If the equipment or the like described in the examples is not available due to discontinuation or the like, other equipment having equivalent performance can be used. Hereinafter, the same applies to other measurement methods.

Examples of the semi-aromatic polyamide resin used in the present invention include polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene isophthalamide (polyamide 6I), polyamide 66 / 6T, polyxylylene adipamide, and polyxylylenese. Examples thereof include bacamide, polyxylylene decamide, polyamide 9T, polyamide 9MT, and polyamide 6I / 6T.
In addition, the semi-aromatic polyamide resin described in paragraphs 0020 to 0058 of JP-A-2016-138163 is also preferably used.

Among the above-mentioned semi-aromatic polyamide resins, from the viewpoint of moldability and heat resistance, it is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 70 mol% or more of the diamine-derived structural unit is xylylene. A semi-aromatic polyamide resin (hereinafter referred to as "XD-based polyamide") derived from an α, ω-linear aliphatic dicarboxylic acid derived from an amine and having 70 mol% or more of a constituent unit derived from a dicarboxylic acid having 4 to 20 carbon atoms. May be preferable).

In the XD-based polyamide, 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more of the constituent units derived from diamine are derived from xylylene diamine and derived from dicarboxylic acid. 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol%, still more preferably 95 mol% or more of the constituent units are derived from α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. do.
The xylylenediamine is preferably paraxylylenediamine, metaxylylenediamine, or a mixture of both, and more preferably contains at least metaxylylenediamine.

Examples of diamines other than metaxylylenediamine and paraximethylenediamine that can be used as the raw material diamine component of XD-based polyamides include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, and octa. An aliphatic diamine such as methylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,3-bis (amino). Methyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane , Bis (aminomethyl) decalin, bis (aminomethyl) tricyclodecane and other alicyclic diamines, bis (4-aminophenyl) ether, paraphenylenediamine, bis (aminomethyl) naphthalene and other aromatic diamines, etc. Can be exemplified, and one kind or a mixture of two or more kinds can be used.
When a diamine other than xylylenediamine is used as the diamine component, it is preferably less than 20 mol%, more preferably 10 mol% or less of the constituent units derived from diamine.

Examples of the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms preferable to be used as a raw material dicarboxylic acid component of a semi-aromatic polyamide resin include succinic acid, glutaric acid, pimelic acid, suberic acid, and adipic acid. Examples of aliphatic dicarboxylic acids such as adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid can be used, and one type or a mixture of two or more types can be used. Among these, the melting point of the semi-aromatic polyamide resin is molded. Adipic acid or sebacic acid is preferable, and adipic acid is more preferable, because it is in an appropriate range.

Examples of the dicarboxylic acid component other than the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid and orthophthalic acid, 1,2-naphthalenedicarboxylic acid and 1,3. -Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalene Examples of naphthalenedicarboxylic acids such as isomers such as dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid can be exemplified, and one kind or a mixture of two or more kinds can be used. When a dicarboxylic acid component other than α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms is used, it is preferably less than 20 mol% of the constituent unit derived from the dicarboxylic acid, and preferably 10 mol% or less. More preferred.

The semi-aromatic polyamide resin is mainly composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, but the other structural units are not completely excluded, and ε-caprolactam and laurolactam are not completely excluded. Needless to say, it may contain a structural unit derived from lactams such as lactams such as, aminocaproic acid, and aliphatic aminocarboxylic acids such as aminoundecanoic acid. In the present invention, the total of the diamine-derived constituent units and the dicarboxylic acid-derived constituent units in the semi-aromatic polyamide resin preferably occupies 90% or more of all the constituent units, and more preferably 95% or more.

The melting point of the semi-aromatic polyamide resin is preferably 150 to 350 ° C, more preferably 180 to 330 ° C, and even more preferably 200 to 300 ° C.
The glass transition temperature of the semi-aromatic polyamide resin is preferably 50 to 150 ° C, more preferably 55 to 120 ° C, and particularly preferably 60 to 100 ° C. Within this range, the heat resistance of the molded product tends to be better.

The melting point of the semi-aromatic polyamide resin is measured as the temperature of the peak top of the endothermic peak at the time of temperature rise observed by the DSC (differential scanning calorimetry) method. The glass transition temperature of the semi-aromatic polyamide resin is measured as the peak top temperature measured by heating and melting the semi-aromatic polyamide resin once to eliminate the influence on the crystallinity due to the thermal history, and then raising the temperature again.
Specifically, using a DSC measuring device, the amount of the semi-aromatic polyamide resin as a sample is about 1 mg, nitrogen is flowed as an atmospheric gas at 30 mL / min, and the temperature rise rate is 10 ° C./min. The melting point is obtained from the temperature of the peak top of the heat absorption peak observed when the mixture is heated from room temperature to a temperature higher than the expected melting point and melted. Next, the melted semi-aromatic polyamide resin is rapidly cooled with dry ice, and the temperature is raised again to a temperature equal to or higher than the melting point at a rate of 10 ° C./min to determine the glass transition temperature. Examples of the DSC measuring instrument include DSC-60 manufactured by SHIMADZU CORPORATION.

The semi-aromatic polyamide resin preferably has a number average molecular weight (Mn) of 6,000 to 30,000, more preferably 8,000 to 28,000, and even more preferably 9,000 to 26,000. It is more preferably 10,000 to 24,000, and even more preferably 11,000 to 22,000. Within such a range, heat resistance, elastic modulus, dimensional stability, and molding processability become better.

The number average molecular weight (Mn) referred to here is derived from the terminal amino group concentration [NH ₂ ] (μ equivalent / g) and the terminal carboxyl group concentration [COOH] (μ equivalent / g) of the semi-aromatic polyamide resin. It is calculated by the following formula.
Number average molecular weight (Mn) = 2,000,000 / ([COOH] + [NH ₂ ])

The semi-aromatic polyamide resin has a molecular weight distribution (weight average molecular weight / number average molecular weight (Mw / Mn)) of preferably 1.8 to 3.1. The molecular weight distribution is more preferably 1.9 to 3.0, still more preferably 2.0 to 2.9. By setting the molecular weight distribution in such a range, it tends to be easy to obtain a three-dimensional structure having excellent mechanical properties.
The molecular weight distribution of the semi-aromatic polyamide resin can be adjusted, for example, by appropriately selecting the type and amount of the initiator and catalyst used at the time of polymerization and the polymerization reaction conditions such as reaction temperature, pressure and time. Further, it can be adjusted by mixing a plurality of kinds of semi-aromatic polyamide resins having different average molecular weights obtained under different polymerization conditions, or by separately precipitating the semi-aromatic polyamide resin after polymerization.

The molecular weight distribution can be determined by GPC measurement. Specifically, Tosoh's "HLC-8320GPC" is used as an apparatus, and Tosoh's "TSK gel Super HM-H" is used as a column, and an eluent is used. The measurement was carried out under the conditions of hexafluoroisopropanol (HFIP) having a trifluorosodium acetate concentration of 10 mmol / L, a resin concentration of 0.02% by mass, a column temperature of 40 ° C., a flow velocity of 0.3 mL / min, and a differential refractometer (RI). , Can be determined as a value converted to standard polymethylmethacrylate (PMMA). The calibration curve is prepared by dissolving 6 levels of PMMA in HFIP and measuring.

The lower limit of the content of the semi-aromatic polyamide resin in the molded product of the present invention is preferably 25% by mass or more, more preferably 30% by mass or more, still more preferably 40% by mass or more. It is more preferably 50% by mass or more, and even more preferably 55% by mass or more. The upper limit of the content is preferably 75% by mass or less, more preferably 70% by mass or less.
The molded product of the present invention may contain only one type of semi-aromatic polyamide resin, or may contain two or more types. When two or more kinds are contained, it is preferable that the total amount is within the above range.

In the molded product of the present invention, it is preferable that the total of the semi-aromatic polyamide resin and the filler containing the fiber described later accounts for 90% by mass or more of the whole.

<Other polyamide resins>
The molded product of the present invention may contain one or more kinds of polyamide resins other than the above semi-aromatic polyamide resin. Examples of such a polyamide resin include polyamide 4, polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610, and polyamide 612.
Of course, in the present invention, the configuration may be substantially free of these other polyamide resins. The term "substantially free" means that the content of the other polyamide resin is 2% by mass or less of the content of the semi-aromatic polyamide resin contained in the molded product of the present invention, preferably 1% by mass or less. , 0.1% by mass or less is more preferable.

<Fiber>
The molded article of the present invention contains fibers.
The fiber is not particularly specified as long as the number average fiber length exceeds 300 μm, and known fibers can be used. The lower limit of the number average fiber length of the fibers is preferably 500 μm or more, more preferably 1.0 mm or more, further preferably 2.0 mm or more, still more preferably 3.0 mm or more. The upper limit of the number average fiber length of the fibers is preferably 6.0 mm or less, more preferably 5.0 mm or less, still more preferably 4.0 mm or less.

The type of fiber is not particularly limited, but is an inorganic fiber such as glass fiber, carbon fiber, plant fiber (including Kenaf, bamboo fiber, etc.), alumina fiber, boron fiber, ceramic fiber, metal fiber (steel fiber, etc.). , And organic fibers such as aramid fiber, polyoxymethylene fiber, polyparaphenylene benzobisoxazole fiber, and ultrahigh molecular weight polyethylene fiber. Among them, at least one selected from carbon fiber, aramid fiber and glass fiber is preferable, at least one selected from carbon fiber and glass fiber is more preferable, and at least one selected from glass fiber. It is more preferably one kind.

The glass fiber has a glass composition such as A glass, C glass, E glass, and S glass, and E glass (non-alkali glass) is particularly preferable. The glass fiber may contain only one kind, or may contain two or more kinds.

The fiber used in the present invention may be a single fiber or a plurality of single fibers twisted together.
The fibers used in the present invention are preferably treated with at least one of a surface treatment agent and a sizing agent. Examples of the surface treatment agent include coupling agents such as silane-based coupling agents, titanium-based coupling agents, and aluminate-based coupling agents. Examples of the focusing agent include epoxy compounds, urethane compounds, carboxylic acid compounds, urethane / maleic acid-modified compounds, and urethane / amine-modified compounds. By using a surface treatment agent and / or a sizing agent, the adhesion to the semi-aromatic polyamide resin can be further improved, and the mechanical strength of the molded product of the present invention can be further improved.

The lower limit of the fiber content used in the present invention is preferably 25% by mass or more, more preferably 26% by mass or more, and further preferably 28% by mass or more. The upper limit of the content is preferably 75% by mass or less, more preferably 65% by mass or less, further preferably 55% by mass or less, still more preferably 45% by mass or less. It is even more preferable that it is 35% by mass or less.
The molded product of the present invention may contain only one type of fiber, or may contain two or more types of fibers. When two or more kinds are contained, it is preferable that the total amount is within the above range.

<Other fillers>
The molded product of the present invention may contain other fillers in addition to the fibers having a number average fiber length of more than 300 μm. Examples of other fillers include fibers having a number average fiber length of 300 μm or less.
Further, in the molded product of the present invention, the content of the filler other than the fiber having the number average fiber length exceeding 300 μm is preferably 10% by mass or less of the fiber having the number average fiber length exceeding 300 μm by 5 mass. % Or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less. Within such a range, the effect of the present invention tends to be exhibited more effectively.

<Black colorant>
The molded article of the present invention may contain a black colorant. By blending a black colorant, a molded product having excellent light-shielding properties can be obtained.
Examples of the black colorant used in the present invention include carbon black. For details of carbon black, the description in paragraph 0021 of JP-A-2011-57977 can be referred to, and these contents are incorporated in the present specification.
When a black colorant such as carbon black is added to the molded product of the present invention, it is preferable to form a masterbatch and then knead it with a semi-aromatic polyamide resin. For details of the masterbatch, the description in paragraphs 0038 to 0042 of JP-A-2011-57977 can be referred to, and these contents are incorporated in the present specification.
Further, when the molded product of the present invention is manufactured by laser welding, it is also preferable to use a light-transmitting black colorant. The light-transmitting black colorant is a colorant having high transmittance in the range of the laser light wavelength to be irradiated, for example, in the range of wavelengths of 800 nm to 1064 nm. Specific examples thereof include niglocin, naphthalocyanine, aniline black, phthalocyanine, porphyrin, perylene, perylene, quoterylene, azo dye, anthraquinone, square acid derivative, and immonium dye. Examples of commercially available products include e-Bind ACW-9871 and e-BIND LTD LTW-8731H, which are colorants manufactured by Orient Chemical Industry Co., Ltd.
When the molded product of the present invention contains a black colorant, the content thereof is preferably 0.1 to 10 parts by mass, and 0.5 to 8 parts by mass with respect to 100 parts by mass of the semi-aromatic polyamide resin. More preferably, 1 to 6 parts by mass is further preferable.
The molded product of the present invention may contain only one type of black colorant, or may contain two or more types of black colorant. When two or more kinds are contained, it is preferable that the total amount is within the above range.

<Talc>
The molded article of the present invention may contain talc. In the present invention, crystallization can be promoted by blending talc.
The blending amount of talc in the molded product of the present invention is preferably 0.05 to 20% by mass, more preferably 0.1 to 10% by mass, and 0.15 to 5% with respect to the molded product. It is more preferably by mass%, and even more preferably 0.2 to 2% by mass. Only one type of talc may be used, or two or more types may be used in combination. In the case of two or more kinds, it is preferable that the total amount is within the above range.

In the present invention, it is particularly preferable that the mixture contains a black colorant and talc, and the mass ratio of the black colorant to the talc (black colorant / talc) in the molded product is 1.5 to 2.5. It is more preferably 8 to 2.2. Within such a range, a molded product having excellent light-shielding property can be obtained while promoting the crystallization of the semi-aromatic polyamide resin.

<Release agent>
The molded product of the present invention may contain a mold release agent. Examples of the release agent include an aliphatic carboxylic acid, a salt of an aliphatic carboxylic acid, an ester of an aliphatic carboxylic acid and an alcohol, an aliphatic hydrocarbon compound having a number average molecular weight of 200 to 15,000, and a polysiloxane-based silicone oil. And so on.

Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acids. Here, the aliphatic carboxylic acid also includes an alicyclic carboxylic acid. Among these, the preferred aliphatic carboxylic acid is a monovalent or divalent carboxylic acid having 6 to 36 carbon atoms, and an aliphatic saturated monovalent carboxylic acid having 6 to 36 carbon atoms is more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, araquinic acid, bechenic acid, lignoseric acid, cellotic acid, melissic acid, tetratriacontanoic acid, montanic acid and adipine. Acids, azelaic acid and the like can be mentioned. Moreover, as a salt of an aliphatic carboxylic acid, a sodium salt, a potassium salt, a calcium salt, and a magnesium salt are exemplified.

As the aliphatic carboxylic acid in the ester of the aliphatic carboxylic acid and the alcohol, for example, the same one as the above-mentioned aliphatic carboxylic acid can be used. On the other hand, examples of the alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, monovalent or polyvalent saturated alcohols having 30 or less carbon atoms are preferable, and aliphatic or alicyclic saturated monovalent alcohols or aliphatic saturated polyvalent alcohols having 30 or less carbon atoms are more preferable.

Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol and the like. Can be mentioned.

Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture containing myricyl palmitate as a main component), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, and glycerin monosteer. Examples thereof include rate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like.

Examples of the aliphatic hydrocarbon having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microwax, polyethylene wax, fisher-tropus wax, α-olefin oligomer having 3 to 12 carbon atoms and the like. Here, the aliphatic hydrocarbon also includes an alicyclic hydrocarbon. The number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less.
Among these, paraffin wax, polyethylene wax or a partial oxide of polyethylene wax is preferable, and paraffin wax and polyethylene wax are more preferable.

When the molded product of the present invention contains a mold release agent, the content of the mold release agent is preferably 0.001 to 2% by mass, preferably 0.01 to 1% by mass, based on the molded product. More preferred. The release agent may be used alone or may contain two or more types. When two or more kinds are contained, it is preferable that the total amount is within the above range. By setting the content of the mold release agent in the above range, it is possible to suppress the decrease in hydrolysis resistance while sufficiently maintaining the effect of mold release, and further effectively suppress the mold contamination during injection molding. ..

<Other additives>
The molded product of the present invention may contain other additives generally used for the polyamide resin in addition to the above, as long as the gist of the present invention is not impaired. Examples of such other additives include resins other than polyamide resins, lubricants, stabilizers, flame retardants, fluorescent bleaching agents, thermoplastic agents, antioxidants, ultraviolet absorbers, antistatic agents, fluidity improving agents and the like. Is exemplified. The total content of the other additives is preferably 5% by mass or less of the molded product. The details of these additives can be referred to in JP-A-2011-57977 and JP-A-2015-129244, the contents of which are incorporated in the present specification.
Examples of other resins include polyester resin, polyphenylene sulfide resin, polyphenylene ether resin, polycarbonate resin, polyarylate resin, phenol resin, epoxy resin and the like.

The polyamide resin composition constituting the molded product of the present invention has a moisture permeability coefficient of 3.0 g · mm / mm after being molded to a thickness of 1 mm and allowed to stand at 40 ° C. and a relative humidity of 90% for 42 hours. preferably day · m ² or less, and more preferably less ^{1.5g · mm / day · m 2} . The lower limit of the water permeability coefficient ^{is preferably 0 g · mm / day · m 2} , but 0.2 g · mm / day · m ² or more is sufficiently practical. The water permeability coefficient is a value measured by the method described in Examples.
Even if the water absorption rate of the polyamide resin is low, it cannot be said that the water permeability coefficient is small. This is because the polyamide resin has a different water absorption rate and diffusion rate.

The molded product of the present invention can be applied to various storage containers having transparent members, electrical and electronic equipment parts, office automation (OA) equipment parts, home electric appliance parts, mechanical mechanism parts, vehicle mechanism parts and the like. In particular, it is preferably used as a camera component. As a camera component, it is used as a barrel, a holder, and a housing. In particular, the molded product of the present invention is preferably used as a camera component of an in-vehicle camera.
When the molded product of the present invention is a camera component, the maximum length is preferably 15 to 40 mm. With such a configuration, it is possible to obtain a camera component having a balance between performance and appearance.
When the molded product of the present invention is a camera component, it contains a member derived from the polyamide resin composition, and the proportion of the member is preferably 1 to 99% by mass. With such a configuration, it is possible to obtain a molded product having an excellent balance between the weight reduction of the camera component and the strength of the camera component.
In particular, the molded product of the present invention is preferably an injection molded product. Of course, it goes without saying that the molded product of the present invention may be a molded product other than an injection molded product.

Next, a method for manufacturing the molded product of the present invention will be described.
The method for producing a molded product of the present invention comprises a semi-aromatic polyamide resin and fibers having a number average fiber length of more than 300 μm, and the terminal carboxyl group concentration of the semi-aromatic polyamide resin is higher than the terminal amino group concentration. Includes injection molding of the resin composition. Details of the semi-aromatic polyamide resin, fibers and the like are the same as described above.
The temperature at the time of injection molding is preferably 260 to 300 ° C.
In the present invention, the method for producing the polyamide resin composition is not particularly specified, and a known method for producing a thermoplastic resin composition can be widely adopted. Specifically, each component is premixed using various mixers such as a tumbler and a Henshell mixer, and then melt-kneaded with a Banbury mixer, a roll, a brabender, a single-screw extruder, a twin-screw extruder, a kneader, or the like. Can produce a polyamide resin composition.

Further, for example, it is also possible to produce a polyamide resin composition without premixing each component or by premixing only a part of the components and supplying the components to an extruder using a feeder for melt kneading. ..
Further, for example, a resin composition obtained by premixing some components and supplying them to an extruder to be melt-kneaded is used as a masterbatch, and this masterbatch is mixed with the remaining components again and melt-kneaded. Polyamide resin compositions can also be produced.

Hereinafter, the present invention will be described in more detail with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

<Semi-aromatic polyamide resin>
(Synthesis of polyamide (MXD6))
Semi-aromatics obtained by polycondensing metaxylylenediamine and adipic acid according to paragraph 0038 of JP2011-140620A, having a terminal amino group concentration of 40 μe equivalent / g and a terminal carboxyl group concentration of 90 μe equivalent / g. Polyamide resin was synthesized. The ratio of the terminal amino group concentration to the terminal carboxyl group concentration ([NH ₂ ] / [COOH]) was 0.44. The obtained semi-aromatic polyamide resin is referred to as "MXD6".

(Synthesis of polyamide (MP6-1))
According to the description of Example 2 of Patent No. 5218705, metaxylylenediamine, paraxylylenediamine and adipic acid are polycondensed, and the terminal carboxyl group concentration ([COOH]) is 95 μe equivalent / g and the terminal amino group concentration. A semi-aromatic polyamide resin having ([NH ₂ ]) of 45 μe equivalent / g was synthesized ([NH ₂ ] / [COOH] = 0.47).

(Synthesis of polyamide (MP6-2))
In a reaction vessel equipped with a stirrer, a splitter, a total crimp, a thermometer, a dropping funnel and a nitrogen introduction tube, and a strand die, weighed 8768.4 g (60 mol) of adipic acid and sodium hypophosphite monohydration. 3.105 g of substance (NaH ₂ PO ₂ · H ₂ O) (phosphorus atom concentration in polyamide resin 50 mass ppm) and 1.61 g of sodium acetate were added, and after sufficient nitrogen substitution, nitrogen was added to an internal pressure of 0.4 MPa. It was filled and heated to 170 ° C. with stirring in the system under a small amount of nitrogen stream. The molar ratio of sodium hypophosphite monohydrate / sodium acetate was 0.67.
To this, 8,335 g (61 mol) of a 7: 3 (molar ratio) mixed diamine of m-xylylenediamine and para-xylylenediamine was added dropwise under stirring to continuously remove the generated condensed water from the system. The temperature was raised to. After the dropping of the mixed xylylenediamine was completed, the melt polymerization reaction was continued for 20 minutes at an internal temperature of 260 ° C. Then, the internal pressure was returned to atmospheric pressure at a rate of 0.01 MPa per minute.
Then, the inside of the system was pressurized with nitrogen again, the polymer was taken out from the strand die, and this was pelletized to obtain about 24 kg of a polyamide resin (MP6-2). The obtained pellets were dried with dehumidifying air at 80 ° C. (dew point −40 ° C.) for 1 hour. The obtained MP6-2 had a terminal carboxyl group concentration ([COOH]) of 37 μe equivalent / g and a terminal amino group concentration ([NH ₂ ]) of 89 μe equivalent / g.

<Terminal group concentration>
The terminal amino group concentration is measured by dissolving 0.5 g of a semi-aromatic polyamide resin in a 30 mL phenol / methanol (4: 1 volume ratio) mixed solution with stirring at 20 to 30 ° C. and titrating with 0.01 N hydrochloric acid. bottom. Regarding the terminal carboxyl group concentration, 0.1 g of a semi-aromatic polyamide resin was dissolved in 30 mL of benzyl alcohol at 200 ° C., and 0.1 mL of a phenol red solution was added in the range of 160 ° C. to 165 ° C. The solution was titrated with a titration solution (KOH concentration: 0.01 mol / L) in which 0.132 g of KOH was dissolved in 200 mL of benzyl alcohol. It was calculated by setting it as the end point.
The unit of terminal group concentration is μ equivalent / g.

<Fiber>
Glass fiber: manufactured by Nippon Electric Glass Co., Ltd., ECS03T-296GH, average fiber length 3.0 mm, short fiber diameter 10.0 μm

<Black colorant>
Carbon black (manufactured by Mitsubishi Chemical Corporation, MA600B)
<Talc>
Micron White # 5000S: Hayashi Kasei Co., Ltd. <Release Agent>
Light Amide WH255: Made by Kyoeisha Chemical Co., Ltd.

Example 1
Semi-aromatic polyamide resin, talc, mold release agent, and black colorant are weighed and dry-blended so that the final composition is as shown in Table 1 below, and then a twin-screw extruder (manufactured by Toshiba Machinery Co., Ltd.) It was charged from the screw root of TEM26SS) using a twin-screw type cassette wading feeder (CE-W-1-MP manufactured by Kubota Co., Ltd.). The black colorant was added after masterbatch using a part of the semi-aromatic polyamide resin within the range of the amount. The glass fiber is charged into the above-mentioned twin-screw extruder from the side of the extruder using a vibrating cassette waving feeder (CE-V-1B-MP manufactured by Kubota), and melt-kneaded with the resin component and the like. , Pellets (polyamide resin composition) were obtained. The temperature of the extruder was set to 280 ° C.

<Measurement of water permeability coefficient>
Using the pellets obtained above, a test piece having a thickness of 100 mm × 100 mm × 1 mm was injection-molded at a cylinder temperature of 280 ° C. and a mold surface temperature of 135 ° C. using NEX80III-9E manufactured by Nissei Resin Industry Co., Ltd.
Next, as shown in FIG. 1, 25 g of calcium chloride particles 12 were placed inside an aluminum cylindrical cup 11 having an inner diameter of 67 mm and an internal height of 80 mm. At a position 50 mm from the inner bottom surface of the cup, the test piece 13 was sealed and allowed to stand in an atmosphere of 40 ° C. and 90% relative humidity for 42 hours. The mass of the calcium chloride particles was measured, and the difference (increase) from that before standing was used as the amount of water permeated, and the water permeation coefficient was calculated.
The unit of the water permeability coefficient is g · mm / day · m ² .

<Bending strength>
After the pellets are dried at 120 ° C. for 4 hours, 100 mm × 100 mm × 2 mm thick molding is performed using a FANUC injection molding machine (100T) under the conditions of a cylinder temperature of 280 ° C. and a mold surface temperature of 135 ° C. The product was injection molded. The molding conditions were such that about 95% of the cavities were filled in about 0.5 seconds and the holding pressure was set at about 80% of the VP switching pressure for 10 seconds.
The bending strength of the obtained molded product was measured according to the ISO-178 standard. The unit of bending strength is MPa.

Example 2
In Example 1, the semi-aromatic polyamide resin was changed to MP6-1, and the others were carried out in the same manner.

Comparative Example 1
In Example 1, the glass fibers were changed to an equal amount of glass flakes (glass flakes REF-015 manufactured by Nippon Sheet Glass Co., Ltd., average thickness 5 μm, average particle size 15 μm), and the others were carried out in the same manner.

Comparative Example 2
In Example 2, the semi-aromatic polyamide resin was changed to MP6-2, and the others were carried out in the same manner.

As is clear from the above results, the molded product of the present invention was obtained with excellent mechanical strength.

11 cups 12 calcium chloride particles 13 test pieces

Claims (11)

The semi-aromatic polyamide resin contains a fiber having a number average fiber length of more than 300 μm, and the terminal carboxyl group concentration of the semi-aromatic polyamide resin is higher than the terminal amino group concentration, and the difference between the terminal carboxyl group concentration and the terminal amino group concentration. Is molded from a polyamide resin composition having a thickness of 47 μ equivalent / g or more and less than 100 μ equivalent / g, and the polyamide resin composition is molded to a thickness of 1 mm under the conditions of 40 ° C. and 90% relative humidity. The water permeation coefficient after standing for 42 hours is 3.0 g · mm / day · m ² or less, the number average fiber length of the fibers is 1.0 mm to 6.0 mm, and it is a camera component, a molded product. .. The molded product according to claim 1, which is used for molding a camera component of an in-vehicle camera having a transparent member. The molded product according to claim 1 or 2, wherein the fiber is at least one selected from carbon fiber and glass fiber. The molded product according to any one of claims 1 to 3, wherein the fiber is treated with at least one of a surface treatment agent and a sizing agent. The molded product according to any one of claims 1 to 4, further comprising a black colorant. The molded product according to any one of claims 1 to 5, further comprising talc. 1. The molded product described in the section. The molded product according to any one of claims 1 to 7, which is an injection-molded product. The molded product according to any one of claims 1 to 8, wherein the maximum length of the camera component is 15 to 40 mm. The molded product according to any one of claims 1 to 9, wherein the camera component contains a member derived from the polyamide resin composition, and the proportion of the member is 1 to 99% by mass. Includes injection molding of a polyamide resin composition comprising a semi-aromatic polyamide resin and fibers having a number average fiber length of more than 300 μm and having a terminal carboxyl group concentration higher than the terminal amino group concentration of the semi-aromatic polyamide resin. , A method for manufacturing a molded product which is a camera component according to any one of claims 1 to 10.

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