Resin composition for camera module with excellent laser transmission and camera module element manufactured using the same

Abstract

Resin composition for a camera module, comprising: 25 to 50 wt.% of a polycarbonate resin; 5 to 30 wt.% of a polycyclohexylenedimethylene terephthalate (PCT) resin; 30 to 50 wt.% of a fibrous filler; and 0.001 to 5% by weight of a dye, wherein the dye comprises Solvent Brown 53 and Solvent Blue 122.

Description

Background area

[0001] The present disclosure relates to a resin composition for a camera module having excellent laser transmittance and a camera module element manufactured using the same. More specifically, the present disclosure relates to a resin composition for a camera module that can be laser welded due to excellent laser transmittance and that has excellent dimensional stability, and to a camera module element manufactured using the same. Discussion of the background

[0002] It is very important to form a driving space so that a driver can clearly see the front, left, right, and rear of a vehicle while driving, and also enable the driver to keep an eye on the adjacent position when stopping and parking the vehicle. For this purpose, a camera is installed inside or on the rear of the vehicle so that an invisible adjacent position can be measured by the camera. In particular, the vehicle's rear camera allows the driver to monitor the blind spot at the rear of the vehicle through a screen, which can prevent an accident from occurring when the vehicle is reversing and ensure the safety of the occupant.

[0003] A vehicle-mounted camera module (or camera lens module) requires reliability and stability as its most important features, as a momentary malfunction of the camera module can have a fatal impact on the occupant's life. Furthermore, the camera module requires high water resistance along with operational stability under intense cold and intense heat conditions. In particular, a high-performance vehicle camera module with more than 1 million pixels, which is being assembled recently, must necessarily have heat dissipation and electromagnetic shielding properties.

[0004] Fig. Figure 1 is an exploded perspective view of a conventional camera module. If we refer to Fig. 1, a camera module 100 comprises a lens assembly (optics) and a housing. According to Fig.1, the lens assembly includes a holder 10, a plurality of lenses 20, spacers (not shown), an O-ring 30, and a barrel 40. Among them, the barrel 40 serves to accommodate the plurality of lenses, is required to have excellent dimensional stability, and is mainly made of an aluminum-based alloy or a polyphenylene sulfide resin composition. Furthermore, the O-ring is attached to the outer circumferential surface of the lens assembly to improve the waterproofing between the lens assembly and the housing. An adhesive is then applied to the lens assembly, which is then assembled with a front body, thus forming the camera module.

[0005] Furthermore, the housing of the camera module 100 includes a front body 50 and a rear body 90, and PCBs 60 and 62 are housed in the housing. In the conventional housing, a gasket 80 is inserted between the front body 50 and the rear body 90, which are then assembled by fastening them using screws 70. However, in recent years, laser welding has been used to ensure excellent waterproof performance and easy assembly.

[0006] Meanwhile, laser welding can achieve high watertightness, bond strength, and the like after joining, and overcome quality issues by reducing burr or dust formation compared to conventional methods such as ultrasonic welding, vibration welding, and thermal welding. Thus, laser welding has attracted attention in the field of various parts manufacturing.

[0007] The first basic component of laser welding is a laser, and the primary component is a near-infrared (NIR) laser beam. The primary near-infrared laser beam is a semiconductor laser with a wavelength range of 800 to 1100 nm. The second basic component is a material for transmitting the laser, which is also referred to as a laser-transmitting material. Depending on the required thickness of the product, the laser-transmitting material must have a suitable laser transmittance so that it transmits the laser in the wavelength range described above. The third basic component is a laser-absorbing material. The transmitted laser passes through the laser-transmitting material and encounters a non-laser-transmitting material, thus forming a joint.An example of a material with excellent laser absorption capacity includes carbon black. A pigment that absorbs the laser in the wavelength range described above without transmitting the laser can be selected and used. Thus, for laser welding, the laser-transmissive material and the laser-absorbing material must be prepared separately, and these materials are made from the same type of materials to help improve the bond strength and strength. In particular, improving the transmittance of the laser-transmissive material is important in laser welding.

[0008] In principle, if a transparent resin material, for example, an amorphous resin such as polycarbonate (PC) and polymethyl methacrylate (PMMA), is used as a laser-transmitting material, its laser transmittance is 90 to 100%, and thus its use is not problematic. On the other hand, if a semi-crystalline resin such as polyamide (PA), polybutylene terephthalate (PBT), or polyoxymethylene (POM) is used for a part requiring heat resistance, chemical resistance, and mechanical strength, it contains a crystalline region, and thus its laser transmittance decreases significantly to 30% or less due to refraction and reflection of the laser during transmission.

[0009] Conventionally, when an amorphous resin such as polycarbonate was alloyed with a semicrystalline resin to increase the transmittance of the semicrystalline resin, the amorphous region could be enlarged, thereby increasing the transmittance. However, in this case, the laser transmittance only increased, and only an achievable level of laser bonding was realized, but the problem arises that it is difficult to produce a material that can exhibit both excellent laser transmittance and bonding strength properties. In addition, laser transmittance differs depending on the composition and thickness of the product, and laser transmittance decreases with increasing product thickness. Thus, it can be stated that it is important to select a resin that has the required properties of a product and to ensure laser transmittance according to the product thickness.

[0010] In addition, in many cases, regardless of whether the product is amorphous or crystalline resin, it is manufactured to have a color (e.g., black) similar to that of a laser-absorbing material. For this purpose, it is important that the laser-transparent material is also manufactured using a special pigment so that it can transmit a laser in its colored state.

[0011] On the other hand, the laser-absorbing material is made of either the same resin as the laser-transmissive material or a material that has excellent compatibility with the laser-transmissive material to prevent a difference in the strength of the materials after bonding. When the same or similar materials are bonded together by laser welding, it is possible to achieve high strength. However, if the content of a fibrous filler or a mineral filler increases and the resin content relatively decreases, the strength after laser bonding is reduced. For this reason, it is important to select materials and compositions appropriately to achieve bond strength. In addition, the laser-absorbing material, unlike the laser-transmissive material, must have a laser transmittance close to 0% at the relevant wavelength, so that it does not transmit any laser.To achieve this transmission, it is necessary to further use additives such as carbon black and a pigment that can absorb the laser at the relevant wavelength without transmitting or reflecting the laser.

[0012] As described above, the laser, laser-transmissive material, and laser-absorbing material required for laser welding have been studied, allowing a product to be manufactured by a laser welding process. However, when the laser welding process is applied to a specific product, there are additional material requirements. Specifically, the laser-transmissive material and laser-absorbing material required for laser welding are bonded together after being injection-molded into a laser-transmissive layer and a laser-absorbing layer, respectively. For this reason, when a crystalline resin is used, problems may arise in that dimensional changes due to mold shrinkage and deformation due to fiber alignment may occur when a fibrous filler is included.Additionally, the problem of dimensions changing due to changes in outside temperature can also arise. Therefore, there is a growing need for materials that exhibit such dimensional stability.

[0013] Examples of resins that can exhibit the relevant properties include polycarbonate (PC). Polycarbonate is an amorphous resin and has advantages in that its laser transmission properties and dimensional stability are excellent, its glass transition temperature (Tg) is high, and thus the dimensional change caused by a change in external temperature from a low temperature to a high temperature is smaller. On the other hand, polycarbonate has the disadvantage of poor chemical resistance, and thus, when the polycarbonate is applied to a vehicle or a product exposed to external environments, it may experience color change and deterioration of physical properties due to chemicals. Thus, methods that can overcome this disadvantage can be considered.One such method involves alloying a semicrystalline resin with polycarbonate, which exhibits high chemical resistance. Typically, semicrystalline resins exhibit excellent mechanical properties, heat resistance, and chemical resistance, but have disadvantages such as a low glass transition temperature, significant dimensional change caused by crystallization, and severe mold shrinkage. Polyester is considered the most suitable semicrystalline resin for alloying with polycarbonate.

[0014] Conventionally, the most commonly used technique is to alloy polybutylene terephthalate (PBT) or polyethylene terephthalate (PET) with polycarbonate (PC), or a product obtained by this technique. PBT or PET has excellent chemical resistance, but its glass transition temperature (Tg) is low, ranging from 50°C to 60°C. For this reason, when PBT or PET is contained in a certain amount or more, it disadvantageously lowers the Tg of polycarbonate, thereby causing dimensional changes at high temperatures. Polyester has excellent electrical properties and low hygroscopic properties, but has the disadvantage of poor thermal properties compared to polyamide.

[0015] Meanwhile, polycyclohexylenedimethylene terephthalate (PCT) resin has a melting temperature (Tm) of approximately 280 °C to 295 °C and a glass transition temperature (Tg) of approximately 89 °C to 92 °C, which are lower than those of PBT or PET. Thus, PCT resin is considered suitable for alloying with PC and used for this purpose.

[0016] Accordingly, there is a need to develop a resin composition that has excellent laser transmission properties suitable for laser welding, low mold shrinkage, low deformation properties, and low dimensional changes with temperature changes, thus exhibiting properties suitable for precision parts for laser welding. In particular, the present disclosure aims to provide an alloy-based resin composition that has higher laser transmission than a conventional laser-transmissive material and has the properties of dimensional stability and chemical resistance.

[0017] Prior art related to the present disclosure is disclosed in Korean Patent No. KR 101993231 B1 (published on June 26, 2019, titled "Mineral Filler-Containing Resin Composition for Camera Barrel Having Enhanced Impact Resistance"). CN103865246 A discloses a glass fiber reinforced resin composition comprising the following components by weight: 40 to 90 parts of thermoplastic resin, 10 to 60 parts of a reinforcing filler, and 0.01 to 20 parts of a flame retardant, the sum of the thermoplastic resin and the reinforcing filler being 100 parts.The thermoplastic resin consists of PC resin (polycarbonate) and PCT resin, with the weight ratio of PC resin (polycarbonate) to PCT resin being 1 / 99 to 99 / 1. The reinforcing filler consists of a flat-section glass fiber with a flat content of 0.1-0.5 and the remainder being a fibrous filler, and the weight ratio of flat-section glass fiber to fibrous filler is 1 / 99 to 99 / 1. The glass fiber reinforced resin composition may include a colorant such as carbon black. Short description

[0018] An object of the present disclosure is to provide a resin composition for a camera module having excellent laser transmission, mechanical strength and dimensional stability.

[0019] Another object of the present disclosure is to provide a resin composition for a camera module having excellent bonding strength to a base material after laser welding, which also has excellent water resistance and water pressure resistance.

[0020] Yet another object of the present disclosure is to provide a resin composition for a camera module having excellent appearance, chemical resistance, moisture resistance and weather resistance.

[0021] Yet another object of the present disclosure is to provide a resin composition for a camera module having excellent miscibility, flowability and moldability.

[0022] Yet another object of the present disclosure is to provide a camera module element manufactured using the resin composition for a camera module.

[0023] One aspect of the present disclosure relates to a resin composition for a camera module. According to the invention, the resin composition for a camera module comprises 25 to 50 wt.% of a polycarbonate resin; 5 to 30 wt.% of a polycyclohexylenedimethylene terephthalate (PCT) resin; 30 to 50 wt.% of a fibrous filler; and 0.001 to 5 wt.% of a dye, wherein the dye includes Solvent Brown 53 and Solvent Blue 122.

[0024] In one embodiment, the polycarbonate resin may have a viscosity average molecular weight (Mv) of 15,000 to 35,000.

[0025] In one embodiment, the PCT resin may have an intrinsic viscosity of 0.6 to 0.8 dl / g.

[0026] In one embodiment, the fibrous filler may comprise one or more of a glass fiber, carbon fiber, silica fiber, potassium titanate fiber, titanium fiber, aramid fiber, and asbestos fiber.

[0027] In one embodiment, the fibrous filler may have an average diameter of 3 to 15 µm and an average length of 0.05 to 5 mm.

[0028] In one embodiment, the resin composition for a camera module may further comprise one or more of a nucleating agent, a release agent, a compatibilizer, an antioxidant, an impact modifier, and a UV absorber.

[0029] In one embodiment, the PCT resin and the fibrous filler may be present in a weight ratio of 1:1 to 1:5.

[0030] In one embodiment, the resin composition for a camera module may have a Charpy impact strength of 12 kJ / m 2 or more and a laser transmission of 80% or more measured on a 2 mm thick specimen at a wavelength of 980 nm.

[0031] In one embodiment, a test specimen comprising a bonding portion having a size of 1.5 mm x 60 mm x 2.0 mm formed by laser welding the resin composition for a camera module and a laser absorbing member at a wavelength of 980 nm may have a bonding strength of 2500 N or more measured at a speed of 50 mm / min using a UTM device.

[0032] In one embodiment, the resin composition for a camera module may have a mold shrinkage rate of 0.5% or less as measured according to ISO 294-4, a linear thermal expansion coefficient of 40 to 50 (µm / m·°C) as measured at a temperature in the range of -40 to 100°C as measured according to ISO 11359, and an average linear thermal expansion coefficient (average of MD and TD values) of 25 to 60 as measured at a temperature in the range of -40 to 100°C as measured according to ISO 11359.

[0033] In one embodiment, the resin composition for a camera module may have a flexural strength of 190 MPa or more and a flexural modulus of 9000 MPa or more as measured according to ISO 178.

[0034] Another aspect of the present disclosure relates to a camera module element manufactured using the resin composition for a camera module.

[0035] In one embodiment, the camera module element may be a tube or a rear body.

[0036] The resin composition for a camera module according to the present disclosure and a camera module element manufactured using the same exhibit excellent laser transmittance, mechanical strength, and dimensional stability. Furthermore, the resin composition and the camera module element exhibit excellent bonding strength to a base material after laser welding, excellent water resistance, and water pressure resistance. Furthermore, the resin composition and the camera module element exhibit excellent appearance, chemical resistance, moisture resistance, and weather resistance. Furthermore, the composition exhibits excellent miscibility, flowability, and moldability. Thus, the resin composition and the camera module element may be particularly well-suited for use as a camera tube for a vehicle, which requires high dimensional stability. Brief description of the drawings Fig. 1 is an exploded perspective view of a conventional camera module. Fig. 2 is an exploded perspective view of a camera module according to an embodiment of the present disclosure. Fig. 3 shows a camera module according to an embodiment of the present disclosure. Fig. 4 shows photos of a camera module according to Example 1. Detailed description of the illustrated embodiments

[0037] In the following description, the detailed description of related known technology or configuration is omitted if it would unnecessarily obscure the subject matter of the present disclosure.

[0038] Furthermore, the terms used in the following description are defined in light of their functions obtained according to embodiments of the present disclosure, and may be changed according to the decision of a user or operator or according to common practice. Accordingly, the definitions of the terms throughout the description should be based on their contents. Resin composition for camera module

[0039] One aspect of the present disclosure is directed to a resin composition for a camera module. According to the invention, the resin composition for a camera module comprises 25 to 50 wt.% of a polycarbonate resin; 5 to 30 wt.% of a polycyclohexylenedimethylene terephthalate (PCT) resin; 30 to 50 wt.% of a fibrous filler; and 0.001 to 5 wt.% of a dye, wherein the dye includes Solvent Brown 53 and Solvent Blue 122.

[0040] The resin composition for a camera module according to the present disclosure will be described in more detail below. Polycarbonate resin

[0041] The polycarbonate (PC) resin used in the present disclosure may be an aromatic polycarbonate resin prepared by reacting a diphenol (aromatic diol compound) with a carbonate precursor such as phosgene, haloformate, or carbonic acid diester.

[0042] In one embodiment, the diphenol may comprise one or more of 4,4'-biphenol, 2,2-bis(4-hydroxyphenyl)propane, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(3-chloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, and 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane. For example, 2,2-bis(4-hydroxyphenyl)propane, called bisphenol A, may be used as the diphenol.

[0043] In one embodiment, the carbonate precursor may comprise one or more of dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, carbonyl chloride (phosgene), diphosgene, triphosgene, carbonyl bromide, and bishaloformate.

[0044] In one embodiment, the polycarbonate resin may have a viscosity-average molecular weight (Mv) of 15,000 to 35,000. If the viscosity-average molecular weight of the polycarbonate resin is less than 15,000, the impact resistance of the resin composition may be reduced, and if the viscosity-average molecular weight is greater than 35,000, the flowability of the resin composition may be reduced.

[0045] In one embodiment, the viscosity-average molecular weight can be determined by dissolving a polycarbonate pellet in methylene chloride, measuring the intrinsic viscosity [η] of the resulting solution at 20 °C using an Ubbelohde-type viscometer, and then calculating the viscosity-average molecular weight according to the following equation 1 (quick viscosity equation): [η]=1.23×10−5×(Mv)0.83

[0046] In one embodiment, the polycarbonate resin is contained in an amount of 25 to 50 wt.%, based on the total weight of the resin composition for a camera module. If the polycarbonate resin is contained in an amount of less than 25 wt.%, it may be difficult to ensure the dimensional stability of the composition, and if the polycarbonate resin is contained in an amount of more than 50 wt.%, the chemical resistance of the composition may be reduced. For example, the polycarbonate resin may be contained in an amount of 30 to 50 wt.%. For example, the polycarbonate resin may be contained in an amount of 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 wt% based on the total weight of the resin composition for a camera module. Polycyclohexylenedimethylene terephthalate resin

[0047] In one embodiment, the polycyclohexylenedimethylene terephthalate (PCT) resin can be prepared either by direct esterification between terephthalic acid and 1,4-cyclohexanedimethanol (CHDM) as monomers or by polycondensation of dimethyl terephthalate and cyclohexanedimethanol by transesterification.

[0048] In one embodiment, the PCT resin may have an intrinsic viscosity of 0.6 to 0.8 dl / g. If the intrinsic viscosity of the PCT resin is less than 0.6 dl / g, the overall mechanical properties of the resin composition of the present disclosure may be deteriorated, and the flowability of the resin composition may increase excessively. If its intrinsic viscosity is greater than 0.8 dl / g, processing during injection molding may be difficult due to the reduced flowability resulting from the high viscosity. In one embodiment, the intrinsic viscosity (η) may be determined by dissolving a PCT resin sample in methylene chloride and measuring the intrinsic viscosity of the resulting solution at 20°C using an Ubbelohde-type viscometer.For example, the PCT resin may have an intrinsic viscosity of 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79 or 0.8 dl / g.

[0049] In one embodiment, the PCT resin is contained in an amount of 5 to 30 wt% based on the total weight of the resin composition for a camera module. If the PCT resin is contained in an amount of less than 5 wt%, it may be difficult to improve the chemical resistance of the polycarbonate resin, and if the PCT resin is contained in an amount of more than 30 wt%, the glass transition temperature (Tg) of the composition may be lowered and its linear expansion coefficient may increase, resulting in a decrease in dimensional stability with temperature changes. For example, the PCT resin may be contained in an amount of 10 to 30 wt%. For example, the PCT resin may be contained in an amount of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, based on the total weight of the resin composition for a camera module. Fibrous filler

[0050] The fibrous filler can serve to improve the mechanical strength and heat resistance of the resin composition and ensure its excellent dimensional stability even under high temperature conditions.

[0051] In one embodiment, the fibrous filler may comprise one or more of a glass fiber, carbon fiber, silica fiber, potassium titanate fiber, titanium fiber, aramid fiber, and asbestos fiber.

[0052] In one embodiment, the fibrous filler may have a circular or elliptical cross-section. In one embodiment, the fibrous filler may have a mean (nominal) diameter of 3 to 15 µm and a mean (nominal) length (cut length) of 0.05 to 5 mm. Under these conditions, the dimensional stability and mechanical strength of the resin composition may be excellent, while its miscibility and moldability may be excellent.

[0053] In one embodiment, the fibrous filler may be surface-treated with a coupling agent. A silane-based compound having an organic functional group, such as a vinyl group, an epoxy group, a mercaptan group, or an amino group, may be used as the coupling agent.

[0054] In one embodiment, the fibrous filler is contained in an amount of 30 to 50 wt% based on the total weight of the resin composition for a camera module. If the fibrous filler is contained in an amount of less than 30 wt%, the mechanical properties targeted by the present disclosure may not be achieved, and dimensional stability may be reduced. If the fibrous filler is contained in an amount of more than 50 wt%, the mechanical properties of the composition may be improved, but its surface properties may be deteriorated, and its flowability may decrease, leading to molding defects. For example, the fibrous filler may be contained in an amount of 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 wt% based on the total weight of the resin composition for a camera module.

[0055] In one embodiment, the PCT resin and the fibrous filler can be present in a weight ratio of 1:1 to 1:5. At this weight ratio, the laser transmission, dimensional stability, and mechanical properties of the composition can be excellent, while its miscibility and dispersibility can be excellent. For example, the PCT resin and the fibrous filler can be present in a weight ratio of 1:3 to 1:5. dye

[0056] The dye of the present disclosure should not only have a coloring effect but also should not affect the changes in laser transmittance, mechanical properties, and glass transition temperature of the composition. Conventional vehicle parts have a black color, which is mainly achieved by using carbon black. However, when carbon black is included in a laser-transparent material, it absorbs the laser wavelength. Therefore, if even a trace amount of soot is included, it lowers the laser transmittance of the material, making laser welding impossible. Accordingly, a dye or pigment other than carbon black should be used to achieve the required black color, but the pigment is unsuitable for use in the composition of the present disclosure because it exhibits color by reflecting light.

[0057] However, the dye can be used in the composition of the present disclosure because it exhibits color by absorbing light only in one specific wavelength range and transmitting light in another specific wavelength range.

[0058] Furthermore, a black dye may be used in the present disclosure. However, there are only a few types of black dyes, and the black dyes have the property of absorbing light in a laser transmission wavelength range (= a wavelength range in which laser welding is performed).

[0059] Accordingly, in the present disclosure, a black color can be realized by combining a plurality of colors that can transmit light in a laser transmission wavelength range (near-infrared rays).

[0060] Examples of the dye that can be used in the present disclosure are anthraquinone dyes, azo dyes, phthalocyanine dyes, methine dyes, oxazine dyes, and metal complex dyes thereof.

[0061] However, according to the invention, the dye comprises Solvent Brown 53 and Solvent Blue 122. When the dye is used, it can achieve a black color and may not deteriorate the permeability properties and mechanical properties of the base resin.

[0062] According to the present invention, the dye is contained in an amount of 0.001 to 5 wt% based on the total weight of the resin composition for a camera module. If the dye is contained in an amount of less than 0.001 wt%, it may be difficult to achieve a black color, and if the dye is contained in an amount of more than 5 wt%, the effect of adding the dye in an increased amount may be negligible, and only the production cost may increase. For example, the dye may be contained in an amount of 0.01 to 0.05 wt%. For example, the dye may be contained in an amount of 0.001, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4 or 5 wt% based on the total weight of the resin composition for a camera module.

[0063] The resin composition for a camera module according to the present disclosure may further comprise an additive depending on its required properties. In one embodiment, the additive may comprise one or more of an antioxidant, a light stabilizer, a release agent, a compatibilizer, and a nucleating agent.

[0064] In one embodiment, the antioxidant may comprise one or more of phenol-type, phosphite-type, thioether-type, and amine-type antioxidants. In one embodiment, the antioxidant may be contained in an amount of 0.001 to 5 wt% based on the total weight of the resin composition for a camera module. When the antioxidant is contained in an amount within this range, the composition can exhibit excellent weather resistance. For example, the antioxidant may be contained in an amount of 0.001, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4 or 5 wt% based on the total weight of the resin composition for a camera module.

[0065] In one embodiment, the light stabilizer may comprise one or more of a benzotriazole-based stabilizer, a sebacate HALS-based stabilizer, a triazine-based stabilizer, a benzophenol-based stabilizer, and an amine-based stabilizer. In one embodiment, the light stabilizer may be contained in an amount of 0.001 to 5 wt% based on the total weight of the resin composition for a camera module. When the light stabilizer is contained in an amount within this range, the composition can exhibit excellent weatherability and yellowing resistance. For example, the light stabilizer may be contained in an amount of 0.001, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4 or 5 wt% based on the total weight of the resin composition for a camera module.

[0066] In one embodiment, the release agent may comprise one or more of a fluorine-containing polymer, silicone oil, a metal salt of stearic acid, a metal salt of montanic acid, montanic acid ester wax, and polyethylene wax. In one embodiment, the release agent may be contained in an amount of 0.001 to 5 wt% based on the total weight of the resin composition for a camera module. When the release agent is contained in an amount within this range, the mold release property of the composition can be excellent while its laser transmittance is not reduced. For example, the release agent may be contained in an amount of 0.001, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4 or 5 wt% based on the total weight of the resin composition for a camera module.

[0067] In one embodiment, the compatibilizer may comprise one or more of styrene-glycidyl methacrylate, styrene-acrylonitrile-glycidyl methacrylate, ethylene methacrylate-glycidyl methacrylate, styrene-maleic anhydride, and styrene-acrylonitrile-maleic anhydride. In one embodiment, the compatibilizer may be contained in an amount of 0.001 to 5 wt% based on the total weight of the resin composition for a camera module. When the compatibilizer is contained in an amount within this range, the miscibility and dispersibility of the components of the composition can be excellent, while the laser transmittance of the composition is not reduced.

[0068] In one embodiment, the nucleating agent may comprise one or more of wollastonite, talc, mica, silica, and clay. In one embodiment, the nucleating agent may be contained in an amount of 0.001 to 5 wt% based on the total weight of the resin composition for a camera module. When the nucleating agent is contained in an amount within this range, the crystallization rate of the composition can be excellently controlled while its laser transmittance is not reduced. For example, the nucleating agent may be contained in an amount of 0.001, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4 or 5 wt% based on the total weight of the resin composition for a camera module.

[0069] In one embodiment, the resin composition for a camera module may have a Charpy impact strength of 12 kJ / m 2 or more and a laser transmittance of 80% or more measured on a 2 mm thick specimen at a wavelength of 980 nm using a laser transmission system (manufactured by EVLaser Co. Ltd., Model: ETM-30).

[0070] For example, the resin composition for a camera module can have a Charpy impact strength of 12 to 25 kJ / m 2 and have a laser transmission of 80 to 99.999% measured on a 2 mm thick specimen at a wavelength of 980 nm.

[0071] In one embodiment, a test specimen comprising a bonding portion measuring 1.5 mm x 60 mm x 2.0 mm formed by laser welding the resin composition for a camera module and a laser absorbing member at a wavelength of 980 nm using a laser system (ELPW-E100, EVLaser Co. Ltd.) may have a bonding strength (or maximum load) of 2500 N or more, measured at a speed of 50 mm / min according to Hyundai-Kia Motor Company's MS216-06 standard using a UTM device (Instron Model 3367). For example, the bonding strength may be 2700 to 3500 N.

[0072] The laser-absorbing element can be formed using a laser-absorbing composition comprising 0.001 to 5 wt.% carbon black. For example, the laser-absorbing element can be formed using a laser-absorbing composition comprising 25 to 50 wt.% of a polycarbonate resin, 5 to 30 wt.% of a polycyclohexylenedimethylene terephthalate (PCT) resin, 30 to 50 wt.% of a fibrous filler, and 0.001 to 5 wt.% carbon black.

[0073] In one embodiment, the resin composition for a camera module may have a mold shrinkage rate of 0.5% or less, as measured according to ISO 294-4. For example, the resin composition for a camera module may have mold shrinkage rates in the machine direction (MD) and transverse direction (TD) of 0.2 to 0.4% and 0.3 to 0.5%, respectively, as measured on a 60 mm x 60 mm x 2 mm test specimen, as measured according to ISO 294-4.

[0074] In one embodiment, the resin composition for a camera module may have a linear thermal expansion coefficient of 40 to 50 (µm / m·°C) measured at a temperature in the range of -40 to 100°C according to ISO 11359 and an average linear thermal expansion coefficient (average of MD and TD values) of 25 to 60 measured at a temperature in the range of -40 to 100°C according to ISO 11359.

[0075] In one embodiment, the resin composition for a camera module may have a linear thermal expansion coefficient in the transverse direction (TD) of 40 to 90 (x 10 -6 / °C).

[0076] In one embodiment, the resin composition for a camera module may have a linear thermal expansion coefficient in the machine direction (MD) of 10 to 40 (µm / m·°C) measured at a temperature in the range of -40 to 100°C according to ISO 11359.

[0077] In one embodiment, the resin composition for a camera module may have a flexural strength of 190 MPa or more, measured according to ISO 178, and a flexural modulus of 9000 MPa or more. For example, the resin composition for a camera module may have a flexural strength of 190 to 240 MPa, measured according to ISO 178, and a flexural modulus of 9000 to 12500 MPa.

[0078] In one embodiment, the resin composition for a camera module can show no cracking even after 20% caustic soda, ethanol, and acetic acid were sprayed onto a test specimen fixed on an ESKV rack once a day for three days. Method for producing a resin composition for a camera module

[0079] In one embodiment, the resin composition for a camera module can be prepared by mixing the above-described components in the above-described amounts using various mixers, melt-kneading the mixture in a Banbury mixer, a roller, a single-screw extruder, a twin-screw extruder, or a kneader to obtain a pellet-type composition, and then subjecting the pellet-type composition to injection molding.

[0080] For example, the resin composition for a camera module can be prepared by kneading at 270 to 290°C using a twin-screw extruder as a mixer to maximize the kneading of the components. Furthermore, the residence time can be minimized to prevent thermal decomposition of the composition during melt kneading. In one embodiment, the optimal screw rotation speed can be determined by considering the dispersibility of the composition. For example, kneading can be performed at a rotation speed of 200 to 400 rpm. Camera module element manufactured using the resin composition for a camera module

[0081] Another object of the present disclosure relates to a camera module element manufactured using the resin composition for a camera module. In one embodiment, the camera module element may be a camera tube or a rear body.

[0082] Fig. 2 is an exploded perspective view of a camera module according to the present disclosure, and Fig. 3 shows a camera module according to an embodiment of the present disclosure. Referring to Fig. 2 and Fig.3, a camera tube 130 of the present disclosure can be manufactured as an integral structure including a camera tube and a front cover of a conventional module. Furthermore, the camera tube 130 or rear body 140 manufactured according to the present disclosure can be joined by laser welding. Thus, it is possible to omit parts including an O-ring, a front cover, and screws used in a conventional camera module. Furthermore, the camera tube 130 or rear body 140 has excellent waterproofness and bonding strength after laser welding, and can exhibit excellent productivity and economy by achieving process simplification.

[0083] Below, the configuration and effect of the present disclosure will be described in more detail with reference to preferred examples. However, these examples are presented as preferred examples of the present disclosure and should not be construed as limiting the scope of the present disclosure in any way. The contents not described here can be sufficiently understood by those skilled in the art, and thus, their description is omitted here.

[0084] Unless otherwise stated, all standards referenced herein, such as ASTM, ISO, etc., are the current versions of the respective standard as of the day before the priority date. Examples and comparison examples

[0085] The components used in the examples and comparative examples are as follows. (A) Polycarbonate resin: 3022PJ (Samyang Corp., Korea) was used. (B) Polycyclohexylenedimethylene terephthalate (PCT) resin: SKYPURA 3302 (SK Chemical Co., Ltd) was used. (C) Fibrous filler: Glass fiber (KCC Co., Ltd., 321) was used. (D1) Solvent Brown 53 (Polysynthren Brown R, Clariant) was used as the dye. (D2) Solvent Blue 122 (Polysynthren Blue R, Clariant) was used as the dye. (D3) Carbon black (Hiblack 50L, Orion Co., Ltd.) was used. (E1) Antioxidant: Irganox1010 (BASF) was used. (E2) Release agent: Licowax OP (Clariant) was used. (E3) Light stabilizer: Tinuvin234 (BASF) was used. Examples 1 to 6 and Comparative Examples 1 to 7

[0086] According to the compositions shown in Table 1 below, the components were melt-kneaded in a twin-screw extruder heated to a temperature of 270 to 290 °C, and then chip-type resin compositions for a camera module were prepared from the melt-kneaded mixtures and then dried in a dehumidifying dryer at 80 °C for 5 hours. Table 1 Components (wt%) (A) (B) (C) (D1) (D2) (D3) (E1) (E2) (E3) Example 1 39 19,86 40 0,02 0,02 - 0,3 0,3 0,5 Example 2 49 9,86 40 0,02 0,02 - 0,3 0,3 0,5 Example 3 29 29,86 40 0,02 0,02 - 0,3 0,3 0,5 Example 4 39 24,86 35 0,02 0,02 - 0,3 0,3 0,5 Example 5 34 19,86 45 0,02 0,02 - 0,3 0,3 0,5 Example 6 29 29,82 40 0,04 0,04 - 0,3 0,3 0,5 Comparison example 1 29,4 29,3 40 - - 0,2 0,3 0,3 0,5 Comparison example 2 58,86 - 40 0,02 0,02 - 0,3 0,3 0,5 Comparison example 3 - 58,86 40 0,02 0,02 - 0,3 0,3 0,5 Comparison example 4 54 4,86 40 0,02 0,02 - 0,3 0,3 0,5 Comparison example 5 19 39,86 40 0,02 0,02 - 0,3 0,3 0,5 Comparison example 6 10 48,86 40 0,02 0,02 - 0,3 0,3 0,5 Comparison example 7 49 29,86 20 0,02 0,02 - 0,3 0,3 0,5 Test example (1)

[0087] For the resin composition specimens for camera modules prepared in Examples and Comparative Examples, the impact strength, laser transmittance, chemical resistance, mold shrinkage rate, and linear expansion coefficient were measured for each specimen according to the methods described below, and the measurement results are shown in Table 2 below.

[0088] (1) Impact strength (kJ / m 2): According to ISO 180, 4 mm thick test specimens of the examples and comparative examples were prepared, and the Charpy impact strength of each of the specimens was measured at room temperature (23°C).

[0089] (2) Laser transmittance (%): Laser transmittance was measured using a laser transmittance measurement system (EVLaser Co., Ltd., Model: ETM-30) under the following conditions: a diode laser, a wavelength of 980 nm, and a set power of 10 MW. Each of the measured specimens of the examples and comparative examples had a size of 60 mm x 60 mm and a thickness of 2 mm. The laser transmittances of the corners and center of each of the injection-molded plate-shaped specimens were measured and averaged. Generally, under the above conditions and at the above specimen thickness, the minimum transmittance at which laser welding is possible is about 30%. If laser welding is performed at a transmittance of less than 30%, the bonding time and power increase, and it is difficult to achieve sufficient bond strength.

[0090] (3) Chemical resistance: For each of the examples and comparative examples, a 1 / 8-inch dumbbell-shaped specimen was prepared and fixed to an ESCR (environmental stress cracking resistance) frame with an elongation of 1%. Then, a 20% sodium hydroxide solution, ethanol, and acetic acid were sprayed onto each specimen once a day for 3 days. The specimen was then observed for cracking.

[0091] (4) Mold shrinkage rate (%): According to ISO 294-4, the mold shrinkage rate of each of the test specimens of the examples and comparative examples, each measuring 60 mm x 60 mm and 2 mm thick, was measured. The mold shrinkage rate was measured in the injection joint direction according to the orientation of the glass fiber as the MD direction and in the rectangular area as the TD direction, and five measurements were averaged. The size (T1) that decreased compared to the existing mold size (60 x 60 mm) was substituted into the existing size (T0), and the mold shrinkage rate was calculated according to the following equation 2: Mold shrinkage rate (%)=[((T0−T1) / T0)×100]

[0092] Generally, in the injection molding industry, although the relevant numerical value can be expressed as a shrinkage rate as 1% relative to 100%, it is generally expressed as 10 / 1000 rather than in %.

[0093] (5) Linear thermal expansion coefficient (linear expansion coefficient) (µm / mm·°C): According to ISO 11359, the linear thermal expansion coefficient of each of the test specimens of the examples and comparative examples, each measuring 5 mm x 5 mm and 5 mm thick, was measured. The linear thermal expansion coefficient was measured in the transverse direction (TD) while heating each specimen from -40°C to 100°C at a heating rate of 5°C / min under a load of 0.05 N, and the dimensional change compared to the initial measured value was determined. Table 2 Impact strength (kJ / m 2 ) Laser transmission (%) chemical resistance Mold shrinkage rate (%) linear expansion coefficient (µm / m·°C) NaOH Ethanol acetic acid Example 1 14,5 90,5 no cracks no cracks no cracks 0.31 to 0.41 43.5 to 45.5 Example 2 15,1 94,6 no cracks no cracks no cracks 0.28 to 0.35 42.3 to 44.4 Example 3 13,6 92,7 no cracks no cracks no cracks 0.35 to 0.44 44.0 to 46.1 Example 4 12,3 95,1 no cracks no cracks no cracks 0.39 to 0.48 45.3 to 47.6 Example 5 15,6 85,6 no cracks no cracks no cracks 0.30 to 0.39 41.3 to 43.8 Example 6 14,2 92,5 no cracks no cracks no cracks 0.36 to 0.44 44.1 to 46.0 Comparison example 1 13,5 10,1 no cracks no cracks no cracks 0.36 to 0.45 43.8 to 46.2 Comparison example 2 18,2 96,8 cracks no cracks no cracks 0.21 to 0.36 38.8 to 41.1 Comparison example 3 10,1 46,2 no cracks no cracks no cracks 0.42 to 1.08 53.5 to 102.5 Comparison example 4 17,1 96 cracks no cracks no cracks 0.28 to 0.34 42.1 to 44.5 Comparison example 5 11,1 90,3 no cracks no cracks no cracks 0.46 to 0.60 49.5 to 63.1 Comparison example 6 13,8 95,8 no cracks no cracks no cracks 0.51 to 0.72 49.8 to 73.3 Comparison example 7 11,9 96,9 no cracks no cracks no cracks 0.45 to 0.70 71.1 to 84.5

[0094] Referring to the results in Table 2 above, it can be seen that Examples 1 to 6 of the present disclosure exhibit excellent laser transmittance and also exhibit impact resistance and dimensional stability. On the other hand, it can be seen that Comparative Example 1, in which carbon black was used instead of the dye of the present disclosure, could not be laser welded due to its reduced laser transmittance; Comparative Examples 2 and 3, which do not contain any of the components of the composition of the present disclosure, exhibit reduced impact resistance, chemical resistance, and laser transmittance; and Comparative Examples 4 to 7, which do not satisfy the conditions of the content range of each component of the composition of the present disclosure, exhibit reduced impact resistance, chemical resistance, and dimensional stability. Comparative Examples 8 to 12Comparative Example 8

[0095] A resin composition was prepared in the same manner as in Example 1 except that polyphenylene sulfide (PPS) resin was used instead of the polycarbonate resin. Comparison example 9

[0096] A resin composition was prepared in the same manner as in Example 1 except that polyphthalamide (PPA) resin was used instead of the polycarbonate resin. Comparison example 10

[0097] A resin composition was prepared in the same manner as in Example 1 except that polyamide 12 (PA12) resin was used instead of the polycarbonate resin. Comparison example 11

[0098] A resin composition was prepared in the same manner as in Example 1 except that polyamide 66 (PA66) resin was used instead of the polycarbonate resin. Comparison example 12

[0099] A resin composition was prepared in the same manner as in Example 1 except that a mixture of polybutylene terephthalate resin and polyethylene terephthalate resin was used instead of the polycarbonate resin. Test example (2)

[0100] Using each of the resin compositions for camera modules prepared in Examples 1 to 6 and Comparative Examples 8 to 12, camera module elements (camera barrel and rear body) were manufactured. The physical properties of the camera module elements were evaluated according to the methods described below, and the evaluation results are shown in Table 3 below. (1) Bonding strength (N): The bonding strength was measured according to the Hyundai-Kia Motor Company standard MS216-06. Specifically, a test piece including a bonding portion measuring 1.5 mm x 60 mm x 2.0 mm was formed by laser welding each resin composition for a camera module and a laser absorbing element at a wavelength of 980 nm using a laser system (ELPW-E100, EVLaser Co. Ltd.), and the bonding strength of the test piece was measured at a speed of 50 mm / min using a UTM device (Instron Model 3367). The laser absorbing element was manufactured using the components and their contents of each of Examples 1 and 6 and Comparative Examples 8 to 12, except that carbon black was used instead of the dye. (2) Laser transmittance (%): The laser transmittance was measured in the same manner as in Test Example 1. (3) Dimensional stability (%): For each shrinkage specimen (60 mm (width) x 60 mm (length) x 2 mm (thickness)), the dimensional change rate was measured between before and after the moisture resistance evaluation (at 50 °C and 95% RH for 240 hours). Specifically, the change rate in the MD and TD directions was calculated before and after the moisture resistance evaluation of the specimen, and then the calculated values ​​were averaged. (4) Mean linear thermal expansion coefficient (MCD): According to ISO 11359, each specimen was prepared and evaluated with a size of 5 mm x 5 mm and a thickness of 5 mm. The MCD was determined by averaging the dimensional changes compared to the initial dimensions measured in the machine direction (MD) and transverse direction (TD) while each specimen was heated from -40 °C to 100 °C at a heating rate of 5 °C / min under a load of 0.05 N. (5) Pressure resistance: The pressure resistance was evaluated by immersing each specimen prepared for bonding strength measurement in a water bath, applying a pressure of 1 to 6 bar to the specimen for 20 seconds, and then checking whether bubbles (leakage) appeared on the laser-welded part. Table 3 Bond strength (N) Laser transmission (%) Dimensional stability (%) Mean linear expansion coefficient Pressure resistance (occurrence of leaks) Example 1 2703 90,5 0,06 42 no leakage occurred Example 6 3208 92,5 0,05 56 no leakage occurred Comparison example8 1500 22 0,05 48 - Comparison example9 3022 16 0,22 28 NG (3 bar leak)- Comparison example10 2803 17 0,27 36 - Comparison example11 2252 60 0,44 39 - Comparison example12 2790 40 0,21 75 -

[0101] Fig. 4 shows photographs of the camera module of Example 1. Referring to the results of Table 3 above, it can be seen that in the case of Comparative Examples 8 to 12 in which resins other than those of the present disclosure were used, the bonding strength was low or the laser transmittance was low, and thus laser welding is possible only when the test pieces are irradiated with high power of 80 to 100 W, and furthermore, the efficiency of laser welding is low, and the dimensional stability or waterproofness is low.

Claims

[1] A resin composition for a camera module, comprising: 25 to 50 wt.% of a polycarbonate resin; 5 to 30 wt.% of a polycyclohexylenedimethylene terephthalate (PCT) resin; 30 to 50 wt.% of a fibrous filler; and 0.001 to 5% by weight of a dye, wherein the dye comprises Solvent Brown 53 and Solvent Blue 122. [2] The resin composition according to claim 1, wherein the polycarbonate resin has a viscosity average molecular weight (Mv) of 15,000 to 35,000. [3] The resin composition according to claim 1, wherein the PCT resin has an intrinsic viscosity of 0.6 to 0.8 dl / g. [4] The resin composition according to claim 1, wherein the fibrous filler comprises one or more of a glass fiber, carbon fiber, silica fiber, potassium titanate fiber, titanium fiber, aramid fiber, and asbestos fiber. [5] The resin composition according to claim 1, wherein the fibrous filler has an average diameter of 3 to 15 µm and an average length of 0.05 to 5 mm. [6] The resin composition according to claim 1, further comprising one or more of a nucleating agent, a release agent, a compatibilizer, an antioxidant, an impact modifier, and a UV absorber. [7] The resin composition according to claim 1, wherein the PCT resin and the fibrous filler are contained in a weight ratio of 1:1 to 1:

5. [8] Resin composition according to claim 1, which has a Charpy impact strength of 12 kJ / m measured on a 4 mm thick test specimen according to ISO 180 (23°C) 2 or more and a laser transmission of 80% or more measured on a 2 mm thick specimen at a wavelength of 980 nm. [9] The resin composition according to claim 1, wherein a test piece comprising a bonding part having a size of 1.5 mm x 60 mm x 2.0 mm formed by laser welding the resin composition for a camera module and a laser absorbing member at a wavelength of 980 nm has a bonding strength (or maximum load) of 2500 N or more measured at a speed of 50 mm / min by means of a UTM device. [10] The resin composition according to claim 1, which has a mold shrinkage rate of 0.5% or less as measured according to ISO 294-4, a linear thermal expansion coefficient of 40 to 50 (µm / m·°C) as measured at a temperature in the range of -40 to 100°C as measured according to ISO 11359, and an average linear thermal expansion coefficient (average of MD and TD values) of 25 to 60 as measured at a temperature in the range of -40 to 100°C as measured according to ISO 11359. [11] A resin composition according to claim 1, which has a flexural strength of 190 MPa or more and a flexural modulus of 9000 MPa or more as measured according to ISO 178. [12] A camera module element manufactured using the resin composition for a camera module according to any one of claims 1 to 11. [13] Camera module element according to claim 12, which is a tube or a rear body.

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