Polyamide resin additives

Abstract

To provide an additive capable of improving peelability of a polyamide resin in molding.SOLUTION: An additive for a polyamide resin contains a compound represented by the following formula (1). In the formula (1), R1 and R2 are each an alkyl group having 4 to 22 carbon atoms or an alkenyl group having 4 to 22 carbon atoms, L1, L2 and L3 are each an alkylene group having 2 to 6 carbon atoms, and X is substituent. m is an integer of 1 to 10, n is an integer of 0 to 10, and m and n satisfy 1≤m+n≤10. When m is 2 or more, the plurality of L1 may be the same or different. When n is 2 or more, the plurality of X and L2 may be the same or different.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an additive for polyamide resins, a resin composition containing the additive, an optical film, and a display device. [Background technology]

[0002] Polyamide resin (nylon resin) is used as a protective film for polarized sunglasses and other products due to its excellent transparency and film mechanical properties. There are two methods for forming films made from polyamide resin: the "melt extrusion method," in which the resin is melted and molded using heat, and the "solvent casting method," in which the resin is dissolved in a solvent, cast, and then the solvent is distilled off to obtain a film.

[0003] The melt extrusion method includes film production techniques such as roll-to-roll, in which molten resin is extruded from an extruder and transported while being wound up on a roll, controlling the thickness, etc. In the solvent casting method, the dope solution is cast onto a metal belt such as SUS314, and after the solvent is distilled off, the film is peeled off from the belt and subjected to a heat stretching process, etc. to obtain a film.

[0004] In the solvent casting method, peeling the film-like resin from the metal belt is an important factor in film productivity, because if the resin can be peeled off from the belt at an early stage after a certain amount of solvent has been distilled off, productivity will improve. Polyamide resins have many amide bonds in their molecular skeletons, which means they tend to adhere well to glass and metal substrates. As a result, they tend to have poorer peelability from the substrate than other resins. This is undesirable from the standpoint of film productivity, and is an issue that needs to be addressed.

[0005] Regarding the above-mentioned problem, Patent Document 1 describes a solution to the problem of poor peelability of a film from a metal belt for a cellulose resin. Furthermore, Patent Documents 2 and 3 describe that the moldability can be improved by adding a small amount of a diamide compound to a polyamide resin. However, the effect is not sufficient, and further improvement is required. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-247531 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-173598 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-234063 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide an additive capable of improving the releasability of polyamide resins during molding. [Means for solving the problem]

[0008] As a result of extensive research to solve the above problems, the present inventors have discovered that the releasability of polyamide resins can be improved by adding a compound represented by formula (1) described below to the polyamide resins, and have thus completed the present invention.

[0009] That is, the present invention relates to an additive for polyamide resins, which contains a compound represented by the following formula (1): [ka] (In formula (1), R1 and R2 are each an alkyl group having 4 to 22 carbon atoms or an alkenyl group having 4 to 22 carbon atoms; L1, L2, and L3 are each an alkylene group having 2 to 6 carbon atoms; L1, L2, and L3 are each an alkylene group having 2 to 6 carbon atoms; and X is a substituent. m is an integer of 1 to 10, and n is an integer of 0 to 10, satisfying 1≦m+n≦10. When m is 2 or more, multiple L1s may be the same or different. When n is 2 or more, multiple Xs and L2s may be the same or different.)

[0010] The present invention also relates to a resin composition containing the above-mentioned additive for polyamide resins and a polyamide resin. The present invention also relates to a molded article made from the above resin composition. The present invention also relates to a display device comprising the above molded product. [Effects of the Invention]

[0011] According to the present invention, there is provided an additive that can improve the releasability of polyamide resins during molding. Furthermore, according to the present invention, there are provided a resin composition, a molded article, and a display device that contain the additive. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Additives for polyamide resins] An additive for polyamide resins according to one embodiment of the present invention contains a compound represented by the following formula (1). [ka] (In formula (1), R1 and R2 each represent an alkyl group having 4 to 22 carbon atoms or an alkenyl group having 4 to 22 carbon atoms; L1, L2, and L3 each represent an alkylene group having 2 to 6 carbon atoms; and X represents a substituent. m represents an integer of 1 to 10, and n represents an integer of 0 to 10, satisfying 1≦m+n≦10. When m is 2 or greater, multiple L1s may be the same or different. When n is 2 or greater, multiple Xs and L2s may be the same or different.)

[0013] The compound represented by formula (1) has a secondary amino structure (-NH-) and an amide group with a medium- to long-chain hydrocarbon (R1 and R2) at the end. It is believed that this compound segregates near the substrate interface due to the interaction between the secondary amino structure and the substrate surface (glass: hydroxyl groups, metal plate: metal atoms), and that the R1 and R2 amide groups improve slipperiness.

[0014] In the above formula (1), R1 and R2 are each an alkyl group having 4 to 22 carbon atoms or an alkenyl group having 4 to 22 carbon atoms. Examples of the alkyl group include linear hydrocarbon groups such as butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, pentadecyl, and octadecyl groups. These linear hydrocarbon groups may have an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group as a substituent, or may be a branched hydrocarbon group.

[0015] The alkenyl group is C n H 2n-1 - (wherein n is an integer of 4 to 22) and is a group having a carbon-carbon double bond. As with the alkyl group, it may have an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group as a substituent. Specifically, it is a group derived from the raw material unsaturated fatty acid described below.

[0016] In one embodiment, R1 and R2 are each an alkyl group having 6 to 18 carbon atoms or an alkenyl group having 6 to 18 carbon atoms.

[0017] L1, L2, and L3 are each an alkylene group having 2 to 6 carbon atoms. Examples include an ethylene group, an n-propylene group, an n-butylene group, and an n-hexylene group. These alkylene groups may have a substituent such as an alkyl group, as long as the effects of the present invention are not impaired. Each of L1, L2, and L3 is preferably an ethylene group or an n-propylene group, and particularly preferably an ethylene group.

[0018] m is an integer of 1 to 10, and n is an integer of 0 to 10. m is preferably an integer of 1 to 5. n is preferably an integer of 0 to 5. m and n satisfy 1≦m+n≦10.

[0019] X is a substituent (other than a hydrogen atom) and is not limited as long as it does not impair the effects of the present invention. Examples of the substituent include alkyl groups such as methyl, ethyl, propyl, and butyl, aryl groups such as phenyl, cyclic hydrocarbon groups such as cyclohexyl, and amide groups with various carboxylic acids.

[0020] The compound represented by formula (1) can be synthesized by any method, including, for example, reacting an amine compound having one or more secondary amino structures (—NH—) with a monocarboxylic acid having a total carbon number of 5 or more, followed by dehydration.

[0021] Examples of the amine compound having one or more secondary amino structures (—NH—) include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and dipropylenetriamine. Examples of monocarboxylic acids having a total carbon number of 5 or more include saturated fatty acids such as pentanoic acid (valeric acid), hexanoic acid, heptanoic acid, octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid, and unsaturated fatty acids such as myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, and nervonic acid.

[0022] In formula (1), some or all of the secondary amino structures (—NH—) may form a salt structure with, for example, a carboxylic acid. In the method for producing the compound represented by formula (1) described below, the obtained compound represented by formula (1) may contain a salt structure formed between a secondary amino structure (—NH—) and a carboxylic acid, but this does not impair the effects of the present invention.

[0023] The compound represented by formula (1) (amidoamine compound) can be produced, for example, by charging an amine compound and a monocarboxylic acid constituting each residue of the amidoamine compound all at once and reacting them. In this production method, the raw materials may be reacted, if necessary, in the presence of an amidation catalyst, for example, at 100 to 200°C for 2 to 15 hours to achieve amidation. Examples of the amidation catalyst include trimethyl borate.

[0024] The acid value of the compound represented by formula (1) is, for example, 20 mgKOH / g or less, preferably 15 mgKOH / g or less, and more preferably 10 mgKOH / g or less. The lower limit of the acid value is not particularly limited, but is, for example, 0 mgKOH / g. The acid value is measured by the method described in the examples.

[0025] The additive for polyamide resins of this embodiment can improve the releasability of polyamide resins during molding, and can therefore be suitably used as a release agent.

[0026] [Resin composition] A resin composition according to one embodiment of the present invention contains the additive for polyamide resins of the present invention described above and a polyamide resin. The polyamide resin may be any known polyamide resin. Examples include ring-opening polymers of lactams, polycondensates of diamines and dibasic acids, and polycondensates of ω-amino acids. These polyamide resins may be used alone or in combination of two or more.

[0027] The polyamide resin may be a crystalline polyamide resin or an amorphous polyamide resin, with the amorphous polyamide resin being preferred since it is easy to impart transparency and surface gloss. The amorphous polyamide resin is obtained by polycondensation of at least one diamine and at least one dicarboxylic acid. Examples of diamines include bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(3-methyl-4-aminocyclohexyl)propane, para-aminodicyclohexylmethane, isophoronediamine, and 2,6-bis(aminomethyl)norbornane. Among these, bis(3-methyl-4-aminocyclohexyl)methane is preferred. Two or more diamines may be used in combination as needed.

[0028] Examples of dicarboxylic acids include terephthalic acid, isophthalic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid. Among these, 1,14-tetradecanedicarboxylic acid is preferred. Two or more dicarboxylic acids may be used in combination as needed.

[0029] The amorphous polyamide resin may be commercially available. Examples of petroleum-based amorphous polyamide resins include Rilsan Clear G110, Rilsan Clear G170, and Rilsan Clear G350 (all manufactured by Arkema), Grilamid TR-55, Grilamid TR-60, and Grilamid TR-90 (all manufactured by EMS-Chemie). Examples of plant-based amorphous polyamide resins include Rilsan (registered trademark) Clair G830Rnew (manufactured by Arkema).

[0030] In one embodiment, the content of the additive for polyamide resin is 0.5 to 5 parts by mass per 100 parts by mass of polyamide resin. Within this range, the effect of the additive for polyamide resin is easily exhibited. Preferably, the content of the additive for polyamide resin is 1 to 4 parts by mass per 100 parts by mass of polyamide resin.

[0031] The resin composition of the present embodiment may contain the additive for polyamide resin and polyamide resin described above, and may further contain other components (optional resin components and optional additives) in addition to these components.

[0032] Examples of the optional resin component include polyolefins such as polyethylene and polypropylene; thermoplastic resins such as polyamide, polyphenylene sulfide resin, polyether ether ketone resin, polysulfone, polyphenylene oxide, polyimide, polyetherimide, and polyacetal; and thermosetting resins such as phenol resin, melamine resin, silicone resin, and epoxy resin. These resin components may be contained alone or in combination.

[0033] Examples of optional additives include inorganic fillers, pigments such as iron oxide; lubricants such as stearic acid, behenic acid, zinc stearate, calcium stearate, magnesium stearate, and ethylene bisstearamide; softeners / plasticizers such as paraffinic process oil, naphthenic process oil, aromatic process oil, paraffin, organic polysiloxane, and mineral oil; antioxidants such as hindered phenolic antioxidants, phosphorus-based heat stabilizers, lactone-based heat stabilizers, and vitamin E-based heat stabilizers; light stabilizers such as hindered amine-based light stabilizers and benzoate-based light stabilizers; ultraviolet absorbers such as benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and benzotriazole-based ultraviolet absorbers; flame retardants; antistatic agents; reinforcing agents such as organic fibers, glass fibers, carbon fibers, and metal whiskers; colorants, other additives, and mixtures thereof.

[0034] The resin composition is mixed, kneaded, and molded by a known method to obtain a molded product. Note that the resin composition of the present embodiment also includes the state of the mixture before molding.

[0035] [Molded products] A molded article according to one embodiment of the present invention is made from the resin composition of the present invention. Examples of molded articles include optical films (polarizer protective films, quarter-wave plates, half-wave plates, viewing angle control films, retardation films such as liquid crystal optical compensation films, display front panels, anti-reflection materials, and base films for touch panel sensors), polarizing sheets, frames for eyeglasses and sunglasses, and transparent cases for tablet devices and smartphones. The resin composition can also be used in optical communication systems, optical switching systems, and optical measurement systems, including waveguides, lenses, optical fibers, optical fiber substrates, coating materials, LED lenses, lens covers, and the like.

[0036] Among these, an optical film is suitable. The optical film can be obtained, for example, by producing an unstretched film using the resin composition of the present invention by a method such as extrusion molding or cast molding, and then stretching the unstretched film. The unstretched film can be produced by a solution casting method (solvent casting method), which is a cast molding method. The solution casting method will be described in detail below. The unstretched film obtained by the solution casting method exhibits substantially optical isotropy. Films exhibiting optical isotropy can be used for optical materials such as liquid crystal displays, and are particularly useful as protective films for polarizing plates. Furthermore, the film obtained by the above method is less likely to develop irregularities on its surface, and has excellent surface smoothness.

[0037] The solution casting method includes, for example, a first step in which the resin composition of the present invention is dissolved in a solvent and the resulting resin solution (dope solution) is cast onto a metal support; a second step in which the solvent contained in the cast resin solution is evaporated and dried to form a film; and a third step in which the film formed on the metal support is peeled off from the metal support and dried by heating. The solvent is not particularly limited, but examples thereof include methanol, methylene chloride (methylene chloride), chloroform, and the like.

[0038] The concentration of the polyamide resin in the resin solution is preferably 10 to 50% by mass, more preferably 15 to 35% by mass.

[0039] The metal support used in the first step may be, for example, an endless belt-shaped or drum-shaped metal support, such as a stainless steel support with a mirror-finished surface.

[0040] When casting a resin solution onto a metal support, it is preferable to use a resin solution that has been filtered to prevent foreign matter from being mixed into the resulting film.

[0041] The drying method in the second step is not particularly limited, but examples include a method in which air at a temperature in the range of 30 to 50°C is blown onto the upper and / or lower surfaces of the metal support to evaporate 50 to 80 mass% of the organic solvent contained in the cast resin solution, thereby forming a film on the metal support.

[0042] Next, in the third step, the film formed in the second step is peeled off from the metal support and heat-dried under higher temperature conditions than in the second step. As a heat-drying method, a method in which the temperature is increased stepwise, for example, under temperature conditions of 100 to 160°C, is preferred because good dimensional stability can be obtained. By heat-drying under these temperature conditions, the organic solvent remaining in the film after the second step can be almost completely removed.

[0043] In the first to third steps, the solvent can be recovered and reused.

[0044] The optical film of this embodiment can be obtained by stretching the resulting unstretched film. Specifically, the optical film can be obtained by longitudinal uniaxial stretching in the mechanical flow direction or transverse uniaxial stretching in a direction perpendicular to the mechanical flow direction. The optical film of this embodiment can also be obtained by free-end uniaxial stretching. Free-end uniaxial stretching refers to longitudinal stretching in a state in which there are no components such as a conveying roller, a supporting plate, or a supporting belt between a pair of stretching rollers that support or contact the film, allowing the film to freely contract and expand in the width direction. The optical film of this embodiment can also be obtained by biaxially stretching the obtained unstretched film using a method such as sequential biaxial stretching by roll stretching and tenter stretching, simultaneous biaxial stretching by tenter stretching, or biaxial stretching by tubular stretching.

[0045] The stretching ratio in at least one direction is preferably 0.1% to 1000%, more preferably 0.2% to 600%, and even more preferably 0.3% to 300%. By setting the stretching ratio within this range, a stretched optical film that is preferable in terms of birefringence, heat resistance, and strength can be obtained.

[0046] The thickness of the optical film of this embodiment is preferably in the range of 20 to 120 μm, more preferably in the range of 25 to 100 μm, and particularly preferably in the range of 25 to 80 μm.

[0047] The molded article of the present embodiment is used as an optical material in display devices such as liquid crystal display devices, plasma displays, organic EL displays, field emission displays, rear projection televisions, etc. For example, it can be suitably used in optical films provided in display devices, such as polarizing plate protective films, quarter-wave plates, half-wave plates, viewing angle control films, retardation films such as liquid crystal optical compensation films, display front panels, antireflection members, and base films for touch panel sensors. [Example]

[0048] The present invention will be described in more detail below with reference to specific examples. [Synthesis of additives] Example 1 Additive A having the following structure was synthesized. [ka]

[0049] A 0.3 L four-neck flask was charged with 36 g of diethylenetriamine (manufactured by Kanto Chemical) and heated to 100°C. Then, 207 g of oleic acid (manufactured by Kanto Chemical) was charged, and the temperature was raised to 170°C, and the reaction was carried out for 5 hours. After sufficient dehydration had progressed, a reduced pressure reaction was carried out at a pressure of 45 Torr for 1 hour. After the temperature was lowered to 95°C, 20 g of water was charged and stirred for 1 hour. Then, the pressure was reduced to 45 Torr at 95°C, and excess water was removed. After removal of the water under reduced pressure, the mixture was removed from the flask, and Additive A, a yellow solid, was obtained. Additive A had an acid value of 7.3 and an amine value of 83. The methods for measuring the acid value and amine value are as follows.

[0050] Acid value measurement method Measurement was carried out according to the method of JIS K0070-1992.

[0051] Amine value measurement method (1) Accurately weigh out 1±0.3 milliequivalents of the sample, place it in an Erlenmeyer flask, and add 20 mL of methyl ethyl ketone (MEK) to dissolve it. (2) Add 5 mL of acetic acid and add 2 or 3 drops of crystal violet acetic acid solution. (3) Titrate with 0.1 mol / L perchloric acid-acetic acid solution while stirring with a magnetic stirrer. (4) The end point is when the color changes from blue-purple to blue and continues for 1 minute. A blank test is also performed at the same time. Calculate the amine value using the following formula. Amine value (mgKOH / g) = 56.10 x [(Va-Vb) / W] x 0.1 x [F20 / {1 + 0.0011(t-20)}] W: sample amount (g) Va: Titration volume (mL) of 0.1 mol / L HClO4 required for this test Vb: Titration volume (mL) of 0.1 mol / L HClO4 required for blank test F20: Potency of 0.1 mol / L HClO4 at 20°C (see the value on the reagent label.) t: HClO4 liquid temperature during titration (℃)

[0052] Example 2 Except for using 29 g of triethylenetetramine (manufactured by Kanto Chemical Co., Ltd.) instead of diethylenetriamine and adding 124 g of oleic acid (manufactured by Kanto Chemical Co., Ltd.), the same procedure as in Example 1 was carried out to obtain a yellow solid, Additive B. Additive B had an acid value of 8.3 and an amine value of 160.

[0053] Example 3 Except for using 38 g of tetraethylenepentamine (manufactured by Kanto Chemical Co., Ltd.) instead of diethylenetriamine and adding 124 g of oleic acid (manufactured by Kanto Chemical Co., Ltd.), the same procedure as in Example 1 was carried out to obtain a yellow solid, Additive C. Additive C had an acid value of 7.7 and an amine value of 192.

[0054] Comparative Example 1 A 0.3 L four-neck flask was charged with 12 g of ethylenediamine (Kanto Chemical) and heated to 100°C. Then, 116 g of oleic acid (Kanto Chemical) was charged, heated to 170°C, and reacted at 170°C for 5 hours. After sufficient dehydration had progressed, the pressure was reduced to 45 Torr and the reaction was continued for another hour. The temperature was then reduced to 95°C, and 15 g of water was charged and stirred for 1 hour. The pressure was reduced to 45 Torr while still at 95°C, and excess water was removed. After removal under reduced pressure, the mixture was removed from the flask to obtain Additive D, a yellow solid. Additive D had an acid value of 6.5 and an amine value of 15.

[0055] [Film production] Example 4 A dope solution (nylon resin solution) was obtained by adding 1 part by mass of additive A, 492 parts by mass of methylene chloride, and 74 parts by mass of methanol to 100 parts by mass of nylon resin (Grilamide TR-90, manufactured by Ms Chemie Japan Co., Ltd.). The dope solution was cast onto a glass plate and a stainless steel (SUS314) substrate, and dried in an oven at 30°C for 20 minutes to remove the solvent, producing a film with a thickness of approximately 60 µm.

[0056] Examples 5 to 8, Comparative Examples 2 and 3 As shown in Table 1, films were produced in the same manner as in Example 4, except that the additives and the amounts added were changed.

[0057] [evaluation] The releasability and surface free energy of the films prepared in the examples and comparative examples were measured. (1) Peelability As described above, a film was prepared by drying in an oven at 30°C for 20 minutes to remove the solvent. After drying for 20 minutes, the substrate was removed from the oven, and the film was immediately peeled off from the substrate. The peelability from the glass substrate and the SUS314 substrate was evaluated based on the following peelability evaluation index.

[0058] -Removability from glass substrate 5: The film peels off naturally without any force. 4: It can be easily peeled off with little force and the film does not deform. 3: Peeling requires force, but the film is hardly deformed. 2: There are some areas that cannot be peeled off without applying force during peeling, and the film becomes slightly deformed. 1: You need to apply enough force to deform the film before peeling it off.

[0059] -Removal from stainless steel substrate (SUS316) 5: The film peels off naturally without any force. 4: It can be easily peeled off with little force and the film does not deform. 3: Peeling requires force, but the film is hardly deformed. 2: Strong force is required to peel off, and the film does not break, but it does deform. 1: Cannot be peeled off (needs enough force to break the film)

[0060] (2) Surface free energy After peeling, the surface free energy of the film on the substrate side and the opposite side was measured. The contact angles of water, diiodomethane, and n-dodecane were measured, and the surface free energy was calculated by the Zisman method. The contact angles were measured using a contact angle measuring device ("MODEL CA-W150" manufactured by Kyowa Interface Science Co., Ltd.).

[0061] (3) Transparency A 40 mm square test piece was prepared and measured using a haze meter (NDH-5000, manufactured by Nippon Denshoku Industries Co., Ltd.). (4) Optical properties A 40 mm square test piece was prepared and conditioned for 1 hour in a simple thermo-hygroscopic booth at 23°C and 55% humidity. The in-plane retardation (Re) and thickness direction retardation (Rth) were then measured using a phase difference measuring device (KOBRA-WR, manufactured by Oji Scientific Instruments Co., Ltd.).

[0062] [Table 1]

[0063] From Table 1, it can be seen that the releasability of the film containing the additive of the Example is superior to that of the Comparative Example, and that the optical properties such as haze are comparable to those of Comparative Example 2, which does not contain any additive. Furthermore, the surface free energy of the film on the substrate side is significantly different from that of the blank film containing no additive, suggesting that the additive is segregated on the substrate side. It is believed that this additive segregation on the substrate surface improves the releasability from the substrate.

Claims

1. An additive for polyamide resins, comprising a compound represented by the following formula (1): 【Chemistry 4】 (In formula (1), R １ and R ２ are each an alkyl group having 4 to 22 carbon atoms or an alkenyl group having 4 to 22 carbon atoms, and L １ , L ２ , and L ３ are each an alkylene group having 2 to 6 carbon atoms, and X is a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, and a cyclohexyl group. m is an integer of 1 to 10, and n is an integer of 0 to 10, satisfying 1≦m+n≦10. When m is 2 or more, a plurality of L １ When n is 2 or more, a plurality of X and L ２ may be the same or different.)

2. R １ and R ２ and each represent an alkyl group having 6 to 18 carbon atoms or an alkenyl group having 6 to 18 carbon atoms.

3. The additive for polyamide resins according to claim 1 or 2, wherein m is an integer of 1 to 5.

4. The additive for polyamide resins according to any one of claims 1 to 3, which is a release agent.

5. A resin composition comprising the additive for polyamide resins according to any one of claims 1 to 4 and a polyamide resin.

6. The resin composition according to claim 5, wherein the content of the additive for polyamide resin is 0.5 to 5 parts by mass per 100 parts by mass of the polyamide resin.

7. 7. The resin composition according to claim 5, wherein the polyamide resin is an amorphous polyamide resin.

8. A molded article made from the resin composition according to any one of claims 5 to 7.

9. A display device comprising the molded product according to claim 8.

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