CN113717519A - Light-transmitting resin composition for laser welding, molded article, composition combination, and method for producing molded article - Google Patents

Abstract

The invention provides a light-transmitting resin composition for laser welding, which contains a polyamide resin having 70 mol% or more of structural units derived from diamine and 70 mol% or more of structural units derived from dicarboxylic acid and derived from an alpha, omega-linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms, and which has a low light transmittance at a wavelength of 700 to 800nm and a high light transmittance at a wavelength of 1070nm, and a molded article, a composition combination, a method for producing a molded article, a vehicle-mounted camera component, and a vehicle-mounted camera. The light-transmitting resin composition for laser welding of the present invention contains, per 100 parts by mass of the specific polyamide resin: 10 to 120 parts by mass of a reinforcing filler, 0.1 to 1.0 part by mass of a light-transmitting pigment having a perylene skeleton, and at least one of copper iodide, potassium iodide and cerium oxide.

Description

Light-transmitting resin composition for laser welding, molded article, composition combination, and method for producing molded article

Technical Field

The present invention relates to a light-transmitting resin composition for laser welding, a molded article, a composition combination, a method for producing a molded article, an in-vehicle camera component, and an in-vehicle camera. The resin composition of the present invention is mainly used as a resin composition (light-transmitting resin composition) on the side through which light for laser welding is transmitted.

Polyamide resins, which are typical engineering plastics, are easy to process and excellent in mechanical properties, electrical properties, heat resistance, and other physical/chemical properties. Therefore, it is widely used for vehicle parts, electric/electronic equipment parts, other precision instrument parts, and the like. Recently, parts having complicated shapes may be produced from polyamide resins, and for example, various welding techniques such as adhesive welding, vibration welding, ultrasonic welding, hot plate welding, injection welding, and laser welding may be used for bonding parts having a hollow portion such as intake manifolds.

However, welding with an adhesive has a problem of environmental load such as environmental pollution, in addition to loss of time until curing. Ultrasonic welding, hot plate welding, and the like have been pointed out as problems in that damage, abrasion powder, and burrs are generated in the product due to vibration and heat, and post-processing is required. In addition, injection welding often requires a special mold or molding machine, and has a problem that it cannot be used when the fluidity of the material is poor.

On the other hand, laser welding is a method of joining two resin members by bringing a resin member (hereinafter, sometimes referred to as "transmissive resin member") having transparency to laser light (hereinafter, sometimes referred to as "non-absorptive or weakly absorptive resin member") into contact with and welding the resin member (hereinafter, sometimes referred to as "absorptive resin member") having absorptivity to laser light. Specifically, the joining surface is irradiated with laser light from the side of the transparent resin member, and the absorbing resin member forming the joining surface is melted by the energy of the laser light to join the members. Laser welding does not generate abrasion powder or burrs, causes little damage to products, and is a material having high laser transmittance, so that processing of polyamide resin products by laser welding techniques has recently been receiving attention.

The transmissive resin member is generally formed by molding a light-transmissive resin composition. As such a light-transmitting resin composition, patent document 1 describes a resin composition for laser welding, which contains: the resin composition for laser welding comprises a semi-aromatic polyamide resin A, an aliphatic polyamide resin B, glass fibers and a light-transmitting pigment, wherein the semi-aromatic polyamide resin A is composed of a structural unit derived from diamine and a structural unit derived from dicarboxylic acid, 70 mol% or more of the structural unit derived from diamine is derived from xylylenediamine, 70 mol% or more of the structural unit derived from dicarboxylic acid is derived from an alpha, omega-linear aliphatic dicarboxylic acid having 8 to 20 carbon atoms, the aliphatic polyamide resin B comprises at least one selected from the group consisting of polyamide 6 and polyamide 610, the resin composition for laser welding contains the aliphatic polyamide resin B in a proportion of 5 to 25 mass% of the resin composition, and the glass fibers are contained in a proportion of 25 to 60 mass% of the resin composition.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2019-006839

Disclosure of Invention

Problems to be solved by the invention

Patent document 1 describes, as a polyamide resin, a polyamide resin composed of an α, ω -linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms (e.g., sebacic acid) and xylylenediamine as laser welding. Polyamide resins composed of sebacic acid and xylylenediamine are suitable for various performances required for laser welding such as low water absorption. However, the present inventors have conducted studies and found that light having a wavelength of 700 to 800nm easily passes through the optical filter. For light having a wavelength of 700 to 800nm, it is required to reduce the light transmittance depending on the application. On the other hand, the resin composition for laser welding is required to maintain the transmittance at a high level with respect to light for laser welding (for example, light having a wavelength of around 1070 nm).

The present invention has been made to solve the above problems, and an object of the present invention is to provide a light-transmitting resin composition for laser welding, which contains a polyamide resin or the like composed of an α, ω -linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms (e.g., sebacic acid) and xylylenediamine, has a low light transmittance at a wavelength of 700 to 800nm and a high light transmittance at a wavelength of 1070nm, and to provide a molded article, a composition combination, a method for producing a molded article, a vehicle-mounted camera component, and a vehicle-mounted camera.

Means for solving the problems

The present inventors have conducted studies based on the above-described problems, and as a result, have found that the above-described problems can be solved by using a light-transmitting pigment having a perylene skeleton as the light-transmitting pigment and precisely adjusting the content thereof. Specifically, the above problems are solved by the following methods.

< 1 > a light-transmitting resin composition for laser welding, which comprises, based on 100 parts by mass of a polyamide resin:

10-120 parts by mass of reinforcing filler,

0.1 to 1.0 part by mass of a light-transmitting pigment having a perylene skeleton, and

at least one of copper iodide, potassium iodide and cerium oxide,

the polyamide resin is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, wherein 70 mol% or more of the diamine-derived structural units are derived from xylylenediamine, and 70 mol% or more of the dicarboxylic acid-derived structural units are derived from an alpha, omega-linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms.

< 2 > the resin composition according to < 1 > wherein,

the xylylenediamine includes 50 to 90 mol% of m-xylylenediamine and 10 to 50 mol% of p-xylylenediamine.

< 3 > the resin composition according to < 1 > or < 2 >, wherein,

the alpha, omega-linear chain aliphatic dicarboxylic acid with 9-20 carbon atoms comprises sebacic acid.

< 4 > the resin composition according to < 1 > wherein,

the xylylenediamine includes 50 to 90 mol% of m-xylylenediamine and 10 to 50 mol% of p-xylylenediamine, and the alpha, omega-linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms includes sebacic acid.

< 5 > the resin composition according to any one of < 1 > to < 4 >, wherein,

when the resin composition is molded into a test piece with a thickness of 1.0mm, the light transmittance at a wavelength of 750nm is less than 5%, and the light transmittance at a wavelength of 1070nm is more than 20%.

< 6 > the resin composition according to any one of < 1 > to < 5 >, wherein,

the content of the light-transmitting pigment having a perylene skeleton is 0.1 to 0.5 part by mass with respect to 100 parts by mass of the polyamide resin.

< 7 > the resin composition according to any one of < 1 > to < 5 >, wherein,

the content of the light-transmitting pigment having a perylene skeleton is 0.15 to 0.8 part by mass with respect to 100 parts by mass of the polyamide resin.

< 8 > a molded article comprising the resin composition as defined in any one of < 1 > to < 7 >.

< 9 > a composition combination having:

the resin composition as described in any one of < 1 > -to < 7 >, and

a light absorbing resin composition comprising a thermoplastic resin and a light absorbing pigment.

< 10 > a method for producing a molded article, which comprises:

a molded article formed from the resin composition described in any one of < 1 > to < 7 > and a molded article formed from a light-absorbing resin composition containing a thermoplastic resin and a light-absorbing pigment are laser-welded.

< 11 > an in-vehicle camera component formed of the resin composition as defined in any one of < 1 > to < 7 > or the composition combination as defined in < 9 >.

< 12 > an in-vehicle camera comprising < 11 > said in-vehicle camera component.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided a light-transmitting resin composition for laser welding, which contains a polyamide resin in which 70 mol% or more of structural units derived from a diamine are derived from xylylenediamine and 70 mol% or more of structural units derived from a dicarboxylic acid are derived from an α, ω -linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms, and which has a low light transmittance at a wavelength of 700 to 800nm and a high light transmittance at a wavelength of 1070nm, and a molded article, a composition combination, a method for producing a molded article, a vehicle-mounted camera component, and a vehicle-mounted camera.

Detailed Description

Hereinafter, a mode for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. The present embodiment described below is an example for explaining the present invention, and the present invention is not limited to the present embodiment.

In the present specification, "to" is used in a sense including a numerical value before and after the "to" as a lower limit value and an upper limit value.

In this specification, unless otherwise specified, various physical property values and characteristic values are values at 23 ℃.

In the present specification, "parts by mass" means relative amounts of components, and "% by mass" means absolute amounts of the components.

The standard shown in the present specification may be a standard based on 1 month and 1 day of 2020 unless otherwise specified, although the measurement method may be different depending on the year.

The light-transmitting resin composition for laser welding according to the present embodiment (hereinafter, may be simply referred to as "the resin composition of the present embodiment") includes 10 to 120 parts by mass of a reinforcing filler, 0.1 to 1.0 part by mass of a light-transmitting pigment having a perylene skeleton, and at least one of copper iodide, potassium iodide, and cerium oxide, with respect to 100 parts by mass of a polyamide resin, wherein the polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, 70 mol% or more of the diamine-derived structural unit is derived from xylylenediamine, and 70 mol% or more of the dicarboxylic acid-derived structural unit is derived from an alpha, omega-linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms.

With such a configuration, a resin composition having low light transmittance at a wavelength of 700 to 800nm and high light transmittance at a wavelength of 1070nm or thereabouts can be provided.

< Polyamide resin >

The resin composition of the present embodiment includes, as the polyamide resin, a polyamide resin that is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and in which 70 mol% or more of the diamine-derived structural unit is derived from xylylenediamine and 70 mol% or more of the dicarboxylic acid-derived structural unit is derived from an α, ω -linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms. In the present specification, such a polyamide resin is sometimes referred to as xylylenediamine-based polyamide resin.

In the present embodiment, by using the xylylenediamine-based polyamide resin, a resin composition which can sufficiently exhibit the performance required for laser welding can be obtained. Specifically, examples of the low water absorption rate, the low tendency to cause variation in heat shrinkage rate due to mold temperature, and the high mechanical strength of the xylylenediamine polyamide resin are given.

In the xylylenediamine-based polyamide resin used in the present embodiment, 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, and still more preferably 99 mol% or more of the diamine-derived structural units are derived from xylylenediamine.

The structural unit derived from xylylenediamine is preferably a structural unit derived from m-xylylenediamine and/or a structural unit derived from p-xylylenediamine, and more preferably contains 50 to 90 mol% of m-xylylenediamine and 10 to 50 mol% of p-xylylenediamine (however, the total amount is not more than 100 mol%), and still more preferably contains 60 to 80 mol% of m-xylylenediamine and 20 to 40 mol% of p-xylylenediamine. In the xylylenediamine-based polyamide resin used in the present embodiment, it is preferable that 95 mol% or more (preferably 99 mol% or more) of the constitutional units derived from xylylenediamine be a constitutional unit derived from m-xylylenediamine and/or a constitutional unit derived from p-xylylenediamine.

As diamines other than xylylenediamine which can be used as the raw material diamine component of the xylylenediamine-based polyamide resin, there can be exemplified: aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2, 4-trimethylhexamethylenediamine, and 2,4, 4-trimethylhexamethylenediamine; alicyclic diamines such as 1, 3-bis (aminomethyl) cyclohexane, 1, 4-bis (aminomethyl) cyclohexane, 1, 3-diaminocyclohexane, 1, 4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) decalin, and bis (aminomethyl) tricyclodecane; diamines having an aromatic ring such as bis (4-aminophenyl) ether, p-phenylenediamine and bis (aminomethyl) naphthalene may be used alone or in combination of two or more.

In the xylylenediamine-based polyamide resin used in the present embodiment, 70 mol% or more, preferably 75 mol% or more, more preferably 85 mol% or more, further preferably 95 mol% or more, and further preferably 99 mol% or more of the constituent units derived from a dicarboxylic acid are derived from an α, ω -linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms.

The alpha, omega-linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms is preferably an alpha, omega-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms.

Examples of the α, ω -linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms include: aliphatic dicarboxylic acids such as sebacic acid, undecanedioic acid, and dodecanedioic acid, and sebacic acid is more preferable. One or a mixture of two or more of alpha, omega-linear aliphatic dicarboxylic acids having 9 to 20 carbon atoms can be used.

Examples of the dicarboxylic acid component other than the α, ω -linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms include aliphatic dicarboxylic acids having less than 9 carbon atoms such as adipic acid, phthalic acid compounds such as isophthalic acid, terephthalic acid, and phthalic acid, 1, 2-naphthalenedicarboxylic acid, 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-naphthalenedicarboxylic acid, 2, 6-naphthalenedicarboxylic acid, and isomers of naphthalenedicarboxylic acid such as 2, 7-naphthalenedicarboxylic acid, and one kind or two or more kinds of them may be used by mixing.

In the xylylenediamine-based polyamide resin, it is preferable that the xylylenediamine used as a raw material contains 50 to 90 mol% of m-xylylenediamine and 10 to 50 mol% of p-xylylenediamine, and the α, ω -linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms contains sebacic acid. More preferably, 90 mol% or more of the diamine as the raw material is xylylenediamine, the xylylenediamine contains 60 to 80 mol% of m-xylylenediamine and 40 to 20 mol% of p-xylylenediamine in a total amount of 99 mol% or more, and 90 mol% or more of the α, ω -linear aliphatic dicarboxylic acid is sebacic acid.

The xylylenediamine-based polyamide resin is mainly composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, but other structural units are not completely excluded, and it is needless to say that structural units derived from lactams such as epsilon-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid may be contained. The main component is a constituent unit constituting the xylylenediamine-based polyamide resin, and the total number of the diamine-derived constituent unit and the dicarboxylic acid-derived constituent unit is the largest in all the constituent units. In the present embodiment, the total of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit in the xylylenediamine-based polyamide resin is preferably 90% or more, more preferably 95% or more of the total structural units.

The resin composition of the present embodiment preferably contains the polyamide resin in a proportion of 30% by mass or more, more preferably 35% by mass or more, still more preferably 40% by mass or more, and yet still more preferably 45% by mass or more of the resin composition. The upper limit of the content of the polyamide resin is preferably 80% by mass or less, and more preferably 75% by mass or less.

The polyamide resin may contain only one kind, or two or more kinds. When two or more are contained, the total amount is preferably in the above range.

< reinforcing Filler >

The resin composition of the present embodiment contains a reinforcing filler in a proportion of 10 to 120 parts by mass with respect to 100 parts by mass of a xylylenediamine-based polyamide resin. By including the reinforcing filler in the above ratio, high mechanical strength can be achieved. The reinforcing filler in the present embodiment does not contain components corresponding to cerium oxide and a nucleating agent described later.

The reinforcing filler that may be contained in the resin composition of the present embodiment has an effect of improving the mechanical properties of the resin composition obtained by blending the reinforcing filler in the resin, and a commonly used reinforcing material for plastics can be used. The reinforcing filler may be organic or inorganic, preferably inorganic. As the reinforcing filler, fibrous reinforcing fillers such as glass fibers, carbon fibers, basalt fibers, wollastonite, and potassium titanate fibers can be preferably used. In addition, fillers such as calcium carbonate, titanium oxide, feldspar type minerals, clay, organized clay, glass beads and other granular or amorphous fillers; scaly reinforcing materials such as glass flakes, mica, and graphite. Among them, fibrous reinforcing fillers, particularly glass fibers, are preferably used in view of mechanical strength, rigidity and heat resistance. As the glass fiber, any of a circular cross-sectional shape and a deformed cross-sectional shape can be used.

The reinforcing filler is more preferably a reinforcing filler surface-treated with a surface treatment agent such as a coupling agent. The glass fiber having the surface treatment agent adhered thereto is preferable because it is excellent in durability, moist heat resistance, hydrolysis resistance, and thermal shock resistance.

The glass fiber includes glass compositions such as a glass, C glass, E glass, S glass, R glass, M glass, D glass, boron-free glass (glass having a boron proportion of 30 mass ppm or less), and E glass (alkali-free glass) is particularly preferable.

The glass fiber is a glass fiber having a cross-sectional shape cut at right angles in the longitudinal direction, which is a perfect circle, an ellipse, a flat, a prolate circle, or a polygon, and exhibiting a fibrous appearance.

The glass fiber used in the resin composition of the present embodiment may be a single fiber or a fiber obtained by twisting a plurality of single fibers.

The form of the glass fiber may be any of "glass roving" obtained by continuously winding a fiber obtained by twisting a single fiber or a plurality of single fibers, "chopped strand" cut in order to have a length of 1 to 10mm, and "milled fiber" pulverized to have a length of 10 to 500 μm. The Glass Fiber is easily available from Asahi Fiber Glass company under the trade names "Glass Chopped Strand" and "Glass Milled Fiber". The glass fibers may be used in combination with fibers having different morphologies.

The cross section of the glass fiber used in the present embodiment may be circular or non-circular. By using glass fibers having a non-circular cross section, warpage of the resulting molded article can be more effectively suppressed. In addition, in the present embodiment, even if glass fibers having a circular cross section are used, warping can be effectively suppressed.

The content of the reinforcing filler in the resin composition of the present embodiment is 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and further preferably 40 parts by mass or more, based on 100 parts by mass of the xylylenediamine-based polyamide resin. The upper limit value is preferably 120 parts by mass or less, and more preferably 110 parts by mass or less, per 100 parts by mass of the xylylenediamine-based polyamide resin.

The content of the reinforcing filler in the resin composition of the present embodiment is preferably 20% by mass or more, and more preferably 25% by mass or more of the resin composition. The upper limit is preferably 70% by mass or less, more preferably 65% by mass or less, still more preferably 60% by mass or less, and still more preferably 55% by mass or less.

The resin composition of the present embodiment may contain only one kind of reinforcing filler, or may contain two or more kinds of reinforcing fillers. When two or more are contained, the total amount is in the above range. The content of the reinforcing filler in the present embodiment includes the amounts of the sizing agent and the surface treatment agent.

< light-transmitting pigment having perylene skeleton >

The resin composition of the present embodiment contains a light-transmitting colorant having a perylene skeleton in an amount of 0.1 to 1.0 part by mass per 100 parts by mass of the xylylenediamine-based polyamide resin. By blending a light-transmitting pigment having a perylene skeleton with a xylylenediamine polyamide resin, a resin composition having a low light transmittance at a wavelength of 700 to 800nm and a high light transmittance at a wavelength of 1070nm or thereabouts can be obtained.

The translucent pigment used in the present embodiment is a black pigment, a black purple pigment, or the like. These light-transmitting pigments are pigments that are black when viewed by human vision. The light-transmitting dye is a dye in which, for example, a polyamide resin, 30 mass% of a glass fiber, and a dye (dye considered to be a light-transmitting dye) are blended so as to total 100 mass%, and when the light transmittance at a wavelength of 1070nm is measured by the measurement method described in the examples described later, the transmittance becomes 20% or more.

The light-transmitting coloring matter may be a dye or a pigment, and is preferably a pigment.

Examples of the pigment having a perylene skeleton include BASF Color & Effect Japan, Spectrasece (registered trademark) Black K0087 (old name: Lumogen (registered trademark) Black FK4280), Spectrasece Black K0088 (old name: Lumogen Black FK4281), and the like.

The resin composition of the present embodiment contains the light-transmitting pigment having a perylene skeleton in an amount of 0.1 part by mass or more, preferably 0.15 part by mass or more, more preferably 0.18 part by mass or more, further preferably 0.20 part by mass or more, and further may be 0.25 part by mass or more and 0.4 part by mass or more, based on 100 parts by mass of the xylylenediamine polyamide resin. The resin composition of the present embodiment contains 1.0 part by mass or less, preferably 0.8 part by mass or less, more preferably 0.7 part by mass or less, and may be 0.5 part by mass or less of the light-transmitting pigment having a perylene skeleton, based on 100 parts by mass of the xylylenediamine-based polyamide resin. By precisely adjusting the amount of the transparent coloring matter having a perylene skeleton as described above, light having a desired wavelength can be selectively transmitted.

The resin composition of the present embodiment may contain only one kind of light-transmitting pigment having a perylene skeleton, or may contain two or more kinds. When two or more are contained, the total amount is preferably in the above range.

The resin composition of the present embodiment may contain a pigment other than the light-transmitting pigment having a perylene skeleton, but preferably does not substantially contain the pigment. The substantial absence means, for example, that the content of the other pigment is less than 1% by mass of the content of the light-transmitting pigment having a perylene skeleton.

< copper iodide, potassium iodide and cerium oxide >

The resin composition of the present embodiment contains at least one of copper iodide, potassium iodide, and cerium oxide. The inclusion of copper iodide tends to further improve the heat resistance of the molded article obtained. Further, by containing potassium iodide, a complex is easily formed in the polyamide resin, and the resin decomposition tends to be more effectively suppressed. Further, since the cerium oxide is originally light brown, the change in color is small even when the cerium oxide is added to natural (natural) or light-colored materials, and the change in color due to oxidation can be reduced. That is, by blending these components, properties according to the application can be imparted.

The proportion of copper iodide in the resin composition of the present embodiment is preferably 0.01 to 1% by mass, more preferably 0.02% by mass or more, and still more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less, in the resin composition.

The resin composition of the present embodiment may contain only one kind of copper iodide, or may contain two or more kinds of copper iodide. When two or more are contained, the total amount is preferably in the above range.

The proportion of potassium iodide in the resin composition of the present embodiment is preferably 0.01 to 2% by mass, more preferably 0.02% by mass or more, and still more preferably 1% by mass or less in the resin composition.

The proportion of cerium oxide in the resin composition of the present embodiment is preferably 0.01 to 2% by mass, more preferably 0.02% by mass or more, and still more preferably 1% by mass or less in the resin composition.

The resin composition of the present embodiment may contain only one kind of cerium oxide, or may contain two or more kinds of cerium oxides. When two or more are contained, the total amount is preferably in the above range.

< Release agent >

The resin composition of the present embodiment may contain a release agent.

Examples of the release agent include: aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids with alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15000, silicone-based silicone oils, ketone waxes, Light amides, and the like, and aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids with alcohols, and more preferably salts of aliphatic carboxylic acids are preferred.

The details of the release agent can be found in paragraphs 0055 to 0061 of Japanese patent application laid-open No. 2018 and 095706, which are incorporated herein by reference.

When the resin composition of the present embodiment contains a release agent, the content thereof is preferably 0.05 to 3% by mass, more preferably 0.1 to 0.8% by mass, and still more preferably 0.2 to 0.6% by mass in the resin composition.

The resin composition of the present embodiment may contain only one release agent, or may contain two or more release agents. When two or more are contained, the total amount is preferably in the above range.

< nucleating agent >

The resin composition of the present embodiment may contain a nucleating agent.

The nucleating agent is not particularly limited as long as it is not melted during melt processing and can form crystal nuclei during cooling, and among them, talc and calcium carbonate are preferable, and talc is more preferable.

The lower limit of the number average particle diameter of the nucleating agent is preferably 0.1 μm or more, more preferably 1 μm or more, and still more preferably 3 μm or more. The upper limit of the number average particle diameter of the nucleating agent is preferably 40 μm or less, more preferably 30 μm or less, still more preferably 28 μm or less, yet more preferably 15 μm or less, and still more preferably 10 μm or less.

The proportion of the nucleating agent in the resin composition of the present embodiment is preferably 0.01 to 1% by mass, more preferably 0.1% by mass or more, and still more preferably 0.5% by mass or less.

The resin composition of the present embodiment may contain only one kind of nucleating agent, or may contain two or more kinds of nucleating agents. When two or more are contained, the total amount is preferably in the above range.

< other ingredients >

The resin composition of the present embodiment may contain other components within a range not departing from the gist of the present invention. Examples of such additives include light stabilizers, antioxidants, ultraviolet absorbers, fluorescent brighteners, anti-dripping agents, antistatic agents, antifogging agents, antiblocking agents, flow improvers, plasticizers, dispersants, antibacterial agents, and flame retardants. The resin composition of the present embodiment may contain a copper compound other than copper iodide, an alkali halide other than potassium iodide, or the like. These components may be used alone or in combination of two or more.

The resin composition of the present embodiment is adjusted such that the total of the respective components is 100 mass% and the contents of the xylylenediamine polyamide resin, the reinforcing filler, the light-transmitting coloring matter having a perylene skeleton, at least one of copper iodide, potassium iodide, and cerium oxide, and other additives are adjusted. In the present embodiment, an embodiment in which the xylylenediamine-based polyamide resin, the reinforcing filler, the light-transmitting coloring matter having a perylene skeleton, and at least one of copper iodide, potassium iodide, and cerium oxide, the nucleating agent, and the release agent occupy 99 mass% or more of the resin composition can be exemplified.

< Properties of resin composition >

The resin composition of the present embodiment is required to have low light transmittance at a wavelength of 700 to 800nm and high light transmittance at a wavelength of 1070nm or thereabouts. For example, when the resin composition of the present embodiment is molded into a test piece having a thickness of 1.0mm, the light transmittance at a wavelength of 750nm is preferably 10% or less (preferably 5% or less, more preferably 0 to 3%, further preferably 0 to 2%, further preferably 0 to 1%), and the light transmittance at a wavelength of 1070nm is 20% or more. The light transmittance at a wavelength of 1070nm is preferably 30% or more, more preferably 40% or more, and still more preferably 50% or more.

When the resin composition of the present embodiment is molded into a test piece having a thickness of 1.0mm, the light transmittance at a wavelength of 800nm is preferably 9% or less (preferably 7% or less, more preferably 5% or less, further preferably 0 to 3%, further preferably 0 to 2%, further preferably 0 to 1%), and the light transmittance at a wavelength of 1070nm is 20% or more.

The upper limit of the light transmittance at a wavelength of 1070nm is preferably as high as possible, but may be, for example, 90% or less, or 70% or less.

The light transmittance was measured as described in examples below.

The resin composition of the present embodiment is preferably excellent in bending characteristics.

Specifically, when the resin composition of the present embodiment is molded into an ISO tensile test piece having a thickness of 4mm, the flexural strength measured in accordance with ISO178 is preferably 200MPa or more, more preferably 210MPa or more, and still more preferably 230MPa or more. In addition, when the resin composition of the present embodiment is molded into an ISO tensile test piece having a thickness of 4mm, the upper limit of the bending strength measured in accordance with ISO178 is not particularly limited, and for example, 50MPa or less, and even 380MPa or less, the required performance is sufficiently satisfied.

When the resin composition of the present embodiment is molded into an ISO tensile test piece having a thickness of 4mm, the flexural modulus measured in accordance with ISO178 is preferably 8000MPa or more, more preferably 8500MPa or more, and still more preferably 9000MPa or more. In addition, when the resin composition of the present embodiment is molded into an ISO tensile test piece having a thickness of 4mm, the upper limit of the bending strength measured in accordance with ISO178 is not particularly limited, and for example, 20000MPa or less, and 19000MPa or less sufficiently satisfies the required performance.

< method for producing resin composition >

The method for producing the resin composition of the present embodiment is not particularly limited, and a method using a single-screw or twin-screw extruder having a device capable of devolatilizing from a vent as a kneader is preferable. The polyamide resin component, the reinforcing filler, the translucent pigment, at least one of copper iodide, potassium iodide and cerium oxide, and other additives which may be added as necessary may be supplied together to a kneader, or the polyamide resin component may be supplied and then the other additives may be sequentially supplied. In order to suppress the crushing at the time of kneading, it is preferable to supply the reinforcing filler from the middle of the extruder. Two or more components selected from the respective components may be mixed and kneaded in advance.

In the present embodiment, the light-transmitting pigment may be prepared in advance by preparing a material that has been subjected to masterbatch gelling with a polyamide resin or the like, and then kneading the material with other components (the polyamide resin component, the reinforcing filler, the light-transmitting pigment, at least one of copper iodide, potassium iodide, and cerium oxide, and the like) to obtain the resin composition of the present embodiment.

The method for producing a molded article using the resin composition of the present embodiment is not particularly limited, and molding methods generally used for thermoplastic resins, i.e., molding methods such as injection molding, blow molding, extrusion molding, and press molding, can be applied. In this case, since the fluidity is good, the molding method is particularly preferably injection molding. In injection molding, the resin temperature is preferably controlled to 250 to 300 ℃.

< composition combination >

The resin composition of the present embodiment and the light absorbing resin composition containing a thermoplastic resin and a light absorbing pigment are preferably used as a combination of compositions for producing a molded article (laser-welded article) by laser welding.

That is, the resin composition of the present embodiment contained in the composition combination functions as a light-transmissive resin composition, and a molded article formed from the light-transmissive resin composition serves as a resin member that transmits laser light during laser welding. On the other hand, a molded article formed of the light absorbing resin composition becomes a resin member that absorbs laser light at the time of laser welding.

[ light-absorbing resin composition ]

The light absorbing resin composition used in this embodiment includes a thermoplastic resin and a light absorbing pigment. In addition, other components such as a reinforcing filler may be contained.

Examples of the thermoplastic resin include a polyamide resin, an olefin resin, a vinyl resin, a styrene resin, an acrylic resin, a polyphenylene ether resin, a polyester resin, a polycarbonate resin, a polyacetal resin, and the like, and from the viewpoint of good compatibility with the light-transmitting resin composition (the resin composition of the present embodiment), the polyamide resin, the polyester resin, and the polycarbonate resin are particularly preferable, and the polyamide resin is more preferable. One or two or more thermoplastic resins may be used.

The polyamide resin used in the light absorbing resin composition is not limited in kind and the like, and is preferably the xylylenediamine polyamide resin.

Examples of the reinforcing filler include fillers capable of absorbing laser light, such as glass fibers, carbon fibers, silica, alumina, carbon black, and inorganic powders coated with a material that absorbs laser light, and glass fibers are preferable. The glass fiber has the same meaning as the glass fiber that can be blended in the resin composition of the present embodiment. The content of the reinforcing filler is preferably 20 to 70% by mass, more preferably 25 to 60% by mass, and still more preferably 30 to 55% by mass.

The light-absorbing pigment includes a pigment having an absorption wavelength in a range of a wavelength of a laser to be irradiated, and for example, in the present embodiment, the light-absorbing pigment has an absorption wavelength in a range of 900nm to 1100 nm. The light-absorbing pigment includes the following pigments: for example, 0.3 part by mass of a dye is blended with 100 parts by mass of a xylylenediamine-based polyamide resin, and when the light transmittance is measured according to the measurement method described in examples described later, the transmittance is less than 30%, and further 10% or less.

Specific examples of the light-absorbing pigment include inorganic pigments (black pigments such as carbon black (e.g., acetylene black, lamp black, thermal black, furnace black, channel black, and ketjen black), red pigments such as iron oxide red, orange pigments such as molybdate orange, and white pigments such as titanium oxide), and organic pigments (yellow pigments, orange pigments, red pigments, blue pigments, and green pigments). Among them, the inorganic pigment is generally strong in hiding power, and therefore, a black pigment is preferable, and further preferable. These light-absorbing pigments may be used in combination of two or more kinds. The content of the light absorbing pigment is preferably 0.01 to 30 parts by mass based on 100 parts by mass of the xylylenediamine polyamide resin.

In the above combination of compositions, it is preferable that 80 mass% or more, more preferably 90 mass% or more, and still more preferably 95 to 100 mass% of the components other than the light-transmitting coloring matter and the reinforcing filler in the resin composition and the components other than the light-absorbing coloring matter and the reinforcing filler in the light-absorbing resin composition are common.

Laser cladding method

Next, a laser welding method will be explained. In the present embodiment, a molded article (transmissive resin member) formed from the resin composition of the present embodiment and a molded article (absorptive resin member) formed from the light absorbing resin composition may be laser welded to produce a molded article. By performing laser welding, the transmissive resin member and the absorptive resin member can be firmly welded without using an adhesive.

The shape of the members is not particularly limited, and since the members are joined to each other by laser welding and used, the members are generally in a shape having at least a surface contact portion (flat surface, curved surface). In laser welding, a laser beam transmitted through a transmissive resin member is absorbed by an absorptive resin member and melted, thereby welding the two members. A molded article formed from the resin composition of the present embodiment has high transparency to laser light, and therefore can be preferably used as a transmissive resin member. Here, the thickness of the member through which the laser beam is transmitted (the thickness of the portion through which the laser beam is transmitted in the laser transmission direction) may be determined as appropriate in consideration of the application, the composition of the resin composition, and others, and is, for example, 5mm or less, preferably 4mm or less.

The laser light source used for laser welding may be determined according to the absorption wavelength of light of the light-absorbing dye, and is preferably a laser light having a wavelength in the range of 900 to 1100nm, and for example, a semiconductor laser or a fiber laser may be used.

More specifically, for example, when welding the transmissive resin member and the absorptive resin member, first, the portions to be welded of the transmissive resin member and the absorptive resin member are brought into contact with each other. In this case, the welding portion of the both is preferably in surface contact, and may be a combination of a flat surface and a flat surface, a curved surface and a curved surface, or a flat surface and a curved surface. Next, the transmissive resin member is irradiated with laser light. In this case, the laser light may be focused on the interface between the both by a lens as necessary. The condensed beam is transmitted through the transmissive resin member, absorbed in the vicinity of the surface of the absorptive resin member, and released to be melted. Then, the heat is also transferred to the transmissive resin member by heat transfer, a molten pool is formed at the interface between the two members, and after cooling, the two members are joined together.

The molded article obtained by welding the transmissive resin member and the absorptive resin member as described above has high weld strength. The molded article of the present embodiment includes a finished product and a part, and also includes a member forming a part of them.

The molded article obtained by laser welding in the present embodiment has good mechanical strength, high weld strength, and little resin damage due to laser irradiation, and therefore can be applied to various applications such as various storage containers, electric/electronic equipment components, Office Automation (OA) equipment components, home appliance components, mechanical device components, and vehicle device components. In particular, the present invention can be preferably used for food containers, medicine containers, grease product containers, hollow parts for vehicles (various containers, intake manifold parts, camera housings, etc.), electric parts for vehicles (various control units, ignition coil parts, etc.) motor parts, various sensor parts, connector parts, switch parts, current breaker parts, relay parts, coil parts, transformer parts, lamp parts, and the like. The resin composition and composition combination of the present invention are particularly suitable for an in-vehicle camera module. In particular, the in-vehicle camera component formed of the resin composition and the composition combination of the present embodiment is suitable for an in-vehicle camera.

Examples

The present invention will be described more specifically with reference to examples. The materials, amounts, proportions, treatment contents, treatment steps and the like shown in the following examples may be appropriately changed without departing from the gist of the present invention. Accordingly, the scope of the present invention is not limited to the specific examples shown below.

When the measurement equipment used in the examples is difficult to obtain due to, for example, a stoppage of production, the measurement can be performed using other equipment having equivalent performance.

< Polyamide resin >

MP 10: the molar ratio M/P was 7:3, and synthesized according to the following synthesis example.

Synthesis example of < MP10 (M/P molar ratio 7:3) >)

Sebacic acid was dissolved by heating in a reaction tank under a nitrogen atmosphere, and then a mixed diamine of p-xylylenediamine (manufactured by mitsubishi gas chemical corporation) and m-xylylenediamine (manufactured by mitsubishi gas chemical corporation) in a molar ratio of 3:7 was slowly added dropwise under pressure (0.35MPa) while stirring the contents so that the molar ratio of the diamine to sebacic acid was about 1:1 and the temperature was increased to 235 ℃. After completion of the dropwise addition, the reaction was continued for 60 minutes to adjust the amount of components having a molecular weight of 1000 or less. After the reaction was completed, the contents were taken out in the form of strands and pelletized by a pelletizer to obtain a polyamide resin (MP10, M/P molar ratio 7: 3).

< Talc >)

# 5000S: micron White manufactured by Linchen chemical Co., Ltd

< stabilizer >

Cuprous iodide: CuI manufactured by Nippon chemical industry Co., Ltd

Potassium iodide: manufactured by Fuji Film Wako Pure Chemical Industries, Inc

Zinc stearate (II): manufactured by Fuji Film Wako Pure Chemical Industries, Inc

< cerium oxide >

Cerium Hydrate90 manufactured by TREBACHER INDUSTRE AG

< reinforcing Filler (glass fiber) >)

ECS 03T-211H: a single fiber having a diameter of 10.5 μm and a length of 3.5mm and a circular cross section manufactured by Nippon Denshoku Co., Ltd

< Release agent >

CS8 CP: montanic acid soap manufactured by Ridong chemical Industrial Co., Ltd

< translucent pigment >

Spectrasce Black K0088: BASF Color & Effect Japan, perylene pigment, Spectrasece Black K0088 (formerly Lumogen Black K0088, formerly Lumogen Black FK4281)

Examples 1 to 8 and comparative examples 1 to 4

< Compound >

The components other than glass fiber were weighed so as to have the compositions shown in the following table 1 or table 2 (each component in table 1 or table 2 is expressed in parts by mass), and dry-blended, and then charged from the screw root of a twin-screw extruder (TEM 26SS, manufactured by toshiba machine, japan) using a twin-screw box type weighing and feeding machine (CE-W-1-MP, manufactured by KUBOTA corporation). The glass fibers were fed into the twin-screw extruder from the side of the extruder using a vibrating box-type weighing feeder (CE-V-1B-MP, manufactured by KUBOTA Co., Ltd.), and melt-kneaded with the resin components and the like to obtain resin composition pellets. The temperature of the extruder was set at 280 ℃.

< flexural Strength and flexural modulus of elasticity >

The resin pellets obtained by the above-mentioned production method were dried at 120 ℃ for 4 hours, and then injection-molded into ISO tensile test pieces having a thickness of 4mm using NEX140III manufactured by Nichisu resin industries, Ltd. The molding was carried out under conditions of a cylinder temperature of 280 ℃ and a mold temperature of 130 ℃.

The flexural strength (unit: MPa) and flexural modulus (unit: MPa) were measured at 23 ℃ based on ISO178 using the above ISO tensile test pieces (4mm thick).

< transmittance >

After the resin composition pellets obtained above were dried at 120 ℃ for 4 hours, a test piece (1.0mm thick) for measuring light transmittance was prepared using an injection molding machine (SE-50D, product of Sumitomo heavy machinery industries, Ltd.). The light transmittance was measured using a visible/ultraviolet spectrophotometer (UV-3100 PC, Shimadzu corporation), and the light transmittance (unit:%) at each wavelength shown in Table 1 or Table 2 was measured.

From the above results, it is clear that the resin compositions described in examples 1 to 8 have a high light transmittance at a wavelength of 1070nm and a low light transmittance at a wavelength of 700 to 800 nm. Further, the mechanical strength can also be maintained at a high level. In contrast, when the amount of the translucent coloring matter blended is less than 0.1 part by mass (comparative examples 1 to 4), the light transmittance at a wavelength of 700 to 800nm is high.

Pellets for forming an absorbent resin member were obtained in the same manner as in example 1 except that the light-transmitting pigment was not blended, and 3 parts by mass of a carbon black masterbatch (carbon black #45 manufactured by Mitsubishi chemical corporation) was blended. The pellets obtained in example 1 and the pellets for forming an absorbent resin member were subjected to laser welding as described in paragraphs 0072 and 0073 of jp 2018-168346 a and fig. 1. It was confirmed that laser welding was appropriately performed.

Claims (12)

1. A light-transmitting resin composition for laser welding, which comprises, per 100 parts by mass of a polyamide resin:

10-120 parts by mass of reinforcing filler,

0.1 to 1.0 part by mass of a light-transmitting pigment having a perylene skeleton, and

at least one of copper iodide, potassium iodide and cerium oxide,

the polyamide resin is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, wherein 70 mol% or more of the diamine-derived structural units are derived from xylylenediamine, and 70 mol% or more of the dicarboxylic acid-derived structural units are derived from an alpha, omega-linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms.

2. The resin composition according to claim 1, wherein,

the xylylenediamine includes 50 to 90 mol% of m-xylylenediamine and 10 to 50 mol% of p-xylylenediamine.

3. The resin composition according to claim 1 or 2, wherein,

the alpha, omega-linear chain aliphatic dicarboxylic acid with 9-20 carbon atoms comprises sebacic acid.

4. The resin composition according to claim 1, wherein,

the xylylenediamine includes 50 to 90 mol% of m-xylylenediamine and 10 to 50 mol% of p-xylylenediamine, and the alpha, omega-linear aliphatic dicarboxylic acid having 9 to 20 carbon atoms includes sebacic acid.

5. The resin composition according to any one of claims 1 to 4,

when the resin composition is molded into a test piece with a thickness of 1.0mm, the light transmittance at a wavelength of 750nm is less than 5%, and the light transmittance at a wavelength of 1070nm is more than 20%.

6. The resin composition according to any one of claims 1 to 5, wherein,

the content of the light-transmitting pigment having a perylene skeleton is 0.1 to 0.5 part by mass with respect to 100 parts by mass of the polyamide resin.

7. The resin composition according to any one of claims 1 to 5, wherein,

the content of the light-transmitting pigment having a perylene skeleton is 0.15 to 0.8 part by mass with respect to 100 parts by mass of the polyamide resin.

8. A molded article comprising the resin composition according to any one of claims 1 to 7.

9. A composition combination having:

the resin composition as set forth in any one of claims 1 to 7, and

a light absorbing resin composition comprising a thermoplastic resin and a light absorbing pigment.

10. A method for producing a molded article, comprising:

a molded article formed from the resin composition according to any one of claims 1 to 7 and a molded article formed from a light-absorbing resin composition containing a thermoplastic resin and a light-absorbing pigment are laser-welded.

11. An in-vehicle camera component formed from the resin composition according to any one of claims 1 to 7 or the composition according to claim 9 in combination.

12. An in-vehicle camera comprising the in-vehicle camera component of claim 11.