JP2010037475A - Transparent resin molded product and optical lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent resin molded product having both excellent reflow heat resistance and excellent optical characteristics, which means high transparency for light in wide range of frequencies including visible light range, and further having excellent light resistance; and to provide an optical lens, composed of the transparent resin molded product, having excellent heat resistance, optical characteristics and light resistance. <P>SOLUTION: The transparent resin molded product is prepared by: molding a molding material containing at least 20 wt.% of a thermoplastic resin; and crosslinking the thermoplastic resin. The transparent resin molded product has at least 80% light transmissivity in over all range of frequencies 400-1,000 nm when the molded product is set to have 2 mm thickness and heated at 200°C for 10 minutes. The optical lens is constituted of the transparent resin molded product. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transparent resin molded body that forms a member such as an optical lens mounted in an electronic component, and an optical lens formed from the transparent resin molded body.

  For parts that require transparency, such as optical lenses, optical films, optical pickups, and Fresnel lenses used in strobes, etc., incorporated in various small electronic components, molded articles of inorganic glass or transparent thermoplastic resin Was used. Here, although inorganic glass is excellent in transparency, it has disadvantages such as being easily damaged due to its large specific gravity and being brittle, and there is a problem that it takes a long time to mold, so a molded body of thermoplastic resin is widely used. (Non-Patent Document 1).

  However, in recent years, the requirements for electronic component members have become increasingly severe. For example, in order to cope with the downsizing of electronic equipment, as a method of mounting electronic components on a circuit board, so-called solder reflow capable of obtaining a high mounting density is becoming popular, and lead having a high melting point due to environmental problems. Since use of free solder is desired, the members of the electronic component are also required to have heat resistance (reflow heat resistance) that can withstand a high temperature of 220 to 270 ° C. in solder reflow using lead-free solder.

There is also a need for a member suitable for use with light having a shorter wavelength or a wider range of wavelengths, or a member that can withstand long-time irradiation with a larger amount of light. For example, if it is used for an optical pickup or the like that supports the Blu-ray method, it has good transparency with respect to light of about 400 nm and light resistance that does not deteriorate (for example, yellowing or whitening) even after prolonged irradiation with laser light. Sex is required. In addition, for use in a strobe, good transparency for all wavelengths in the visible region including light of about 400 nm is required, and it does not deteriorate even when repeated with a large amount of light at a high temperature of about 100 ° C. Light resistance is required.
“Transparent Resins That Have Been Here” Industrial Research Co., Ltd., page 48, 2001

  However, thermoplastic resins such as polymethyl methacrylate, polycarbonate, and polyethylene terephthalate are excellent in transparency in the visible light region, but do not have reflow heat resistance corresponding to recent demands. Polysulfone, polyethersulfone, polyimide, polyetherimide, and the like have better heat resistance than the above-mentioned resins. However, the resin moldings obtained from these resins have low transparency in the visible light region and the resin has a benzene ring. There was a problem of high birefringence due to the inclusion. Thus, there are no known thermoplastic resins that satisfy all of the above requirements, and therefore excellent reflow heat resistance, excellent optical properties, and light resistance, particularly excellent for light of about 400 nm. Development of a transparent resin molding having high light resistance has been demanded.

  The present invention provides a transparent resin molded article having excellent reflow heat resistance and excellent optical properties, that is, high transparency to light in a wide wavelength range including the visible light region, and further having excellent light resistance, and the transparent resin molded article It is an object of the present invention to provide an optical lens made of a body and having excellent heat resistance, optical characteristics, and light resistance.

  As a result of diligent research, the present inventor has used a specific thermoplastic resin, and by cross-linking this thermoplastic resin, preferably, when selecting a cross-linking aid for further cross-linking the thermoplastic resin, and during molding and cross-linking By selecting the atmospheric conditions, etc., it is possible to obtain a transparent resin molded product having excellent reflow heat resistance, excellent optical properties (that is, high transmittance in the visible to near infrared range), and excellent light resistance. The headline and the present invention were completed. The invention of each claim will be described below.

The invention described in claim 1
A molding material containing 20% by weight or more of a thermoplastic resin, compounded and molded, and a transparent resin molded body obtained by crosslinking the thermoplastic resin,
When the molded body is 2 mm thick and heated at 200 ° C. for 10 minutes, the transparent resin molded body has a light transmittance of 80% or more over the entire wavelength range of 400 to 1000 nm.

  The transparent resin molded product of the present invention can be crosslinked by heating, radiation irradiation, or the like, and contains 20% by weight or more of a thermoplastic resin having a light transmittance of 80% or more over the entire wavelength range of 400 to 1000 nm. The material can be obtained by first compounding and molding and then crosslinking. By cross-linking, a molded product having excellent heat resistance, reflow heat resistance and light resistance can be obtained. Furthermore, excellent rigidity, creep resistance, wear resistance and the like can be easily obtained. On the other hand, molding is easy at the stage before cross-linking, and therefore, by carrying out predetermined molding at this stage and performing cross-linking by heating, irradiation, etc. after molding, it has excellent characteristics and is desired. It is possible to obtain a molded body having the shape as described above.

  A molding method is not particularly limited, and a known molding method can be employed. For example, an injection molding method, an injection compression molding method, a press molding method, an extrusion molding method, a blow molding method, a vacuum molding method and the like can be mentioned. In the case of forming into a film, extrusion molding using a T-die, calender molding, inflation molding, press, casting, thermoforming, etc. can be used, but the degree of freedom in shape and mass productivity are particularly excellent Therefore, an injection molding method is preferable. By making the thermoplastic resin into a transparent polyamide and a transparent fluororesin, which will be described later, and further containing a specific crosslinking aid (triallyl isocyanurate or the like), a molding material particularly preferable for the injection molding method can be obtained.

  Examples of the crosslinking method include a method using heating, a method of crosslinking by irradiating with an electron beam or other radiation, and the method of crosslinking by irradiating with radiation involves temperature and fluidity limitations during molding. Therefore, it is preferable because it is easy to control. Examples of radiation include γ rays in addition to electron beams. The degree of cross-linking is not particularly limited, and is set according to the intended resin molded product.

  The transparent resin molded product of the present invention is characterized in that when it is 2 mm thick and heated at 200 ° C. for 10 minutes, the transmittance is 80% or more in the entire range of 400 to 1000 nm. That is, when a molded product having a thickness of 2 mm was cut out from the transparent resin molded product of the present invention, the cut molded product was heated at 200 ° C. for 10 minutes, and the transmittance was measured, it was substantially 400 to 1000 nm. In the entire range, the transmittance is 80% or more.

  The heating for 10 minutes at 200 ° C. is a condition considering the solder reflow resistance when using lead-free solder. When the transmittance is lowered by heating at 200 ° C. for 10 minutes and becomes less than 80%, the transparency of the product is lowered during solder reflow, which may cause a problem in optical performance.

  In addition, the transmittance | permeability with respect to the wavelength of this range of the inorganic glass of thickness 2mm is 80% or more. Therefore, the transparent resin molded body of the present invention has transparency comparable to inorganic glass, has transparency superior to thermoplastic resins such as polymethyl methacrylate, polycarbonate, polyethylene terephthalate, etc. It can be used widely. Moreover, since the transparent resin molding of this invention has high transparency also in a near infrared region, it is preferably used also for near infrared.

  The transparent resin molded product of the present invention is preferably made by using, as a raw material, a molding material containing 20% by weight or more of a crosslinkable thermoplastic resin having a high transmittance in the visible to near infrared range. It can be obtained by selecting the atmospheric condition at the time of molding and cross-linking, such as selection of a cross-linking aid when cross-linking the plastic resin. When the content of the crosslinkable thermoplastic resin is less than 20% by weight, the molding material is slow to solidify and the viscosity is too low, which causes a problem that extrusion and injection molding become difficult.

  The thermoplastic resin constituting the molding material is preferably one or more resins selected from the group consisting of transparent polyamide and transparent fluororesin (Claim 2). One type of resin may be used alone, or two or more types of resins selected from the above group may be mixed and used.

  These resins not only have crosslinkability and thermoplasticity, but inherently have good light transmittance. For this reason, when these resins are molded and cross-linked, for example, when a molded body having a thickness of 2 mm is produced, the light transmittance in the entire range of 400 to 1000 nm of the molded body is 80% or more. It becomes possible. Furthermore, excellent heat resistance and light resistance are easily obtained.

  Furthermore, these resins are also preferable from the viewpoint of excellent injection moldability, and even when a crosslinking aid is mixed, a molded product can be easily produced by an injection molding machine. In particular, by blending a specific crosslinking aid (triallyl isocyanurate or the like), a molding material having excellent injection moldability is obtained. Here, the “resin” is mainly composed of a polymer, but may contain an oligomer or a monomer. Preferably, the weight average molecular weight is 5000 or more.

  The transparent polyamide is a polyamide resin having a transparency in which the light transmittance is 80% or more over the entire wavelength range of 400 to 1000 nm, and is crosslinked by radiation irradiation or the like, for example, Japanese Patent Application Laid-Open No. 62-121726. Those disclosed in JP-A-63-170418 and JP-A-2004-256812 can be used. These are obtained by using a monomer having a ring such as an aromatic ring or an alicyclic ring, and are amorphous polyamides having a high glass transition point. Of these, a condensation polymer of 1,10-decanedicarboxylic acid and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane is preferably used.

  The transparent fluororesin is a fluororesin having a transparency in which the light transmittance is 80% or more in the entire wavelength range of 400 to 1000 nm, and is crosslinked by radiation irradiation or the like, polyvinylidene fluoride (PVdF), Ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polymer blends thereof Those selected from the group consisting of these are preferably used (claim 4).

  Crosslinking of the thermoplastic resin in the production of the transparent resin molded product of the present invention is performed while melting and kneading the thermoplastic resin and other raw materials, but promotes crosslinking to obtain excellent heat resistance and light resistance. Therefore, it is preferably performed in the presence of a crosslinking aid. Therefore, it is preferable that the molding material further contains a crosslinking aid.

  The invention according to claim 5 is characterized in that the molding material further contains triallyl isocyanurate as a crosslinking aid, and the compounding, molding, and crosslinking of the thermoplastic resin are performed under the interruption of oxygen. The transparent resin molded product according to any one of claims 1 to 4.

  Among the above-mentioned crosslinking aids, it is preferable to use triallyl isocyanurate and to perform all the steps from compounding the molding material to molding and crosslinking the thermoplastic resin under the shielding of oxygen. When triallyl isocyanurate is used as a crosslinking aid and compounding, molding and crosslinking are performed under the interruption of oxygen, when the thickness is 2 mm and heating at 200 ° C. for 10 minutes, the light is irradiated in the entire wavelength range of 400 to 1000 nm. A molded body having a transmittance of 80% or more can be easily obtained. Further, when compounding, molding, and crosslinking are performed in the presence of oxygen, the molded body may turn yellow. However, this problem can be prevented by performing the blocking under oxygen.

  For example, it is preferable to use triallyl isocyanurate as a crosslinking aid because the injection moldability of the molding material is improved. That is, by containing 20% by weight or more of a thermoplastic resin selected from the group consisting of transparent polyamide and transparent fluororesin, a molding material excellent in injection moldability is obtained, and injection molding is easy even when a crosslinking aid is blended. However, when triallyl isocyanurate is used as a crosslinking aid, even when the blending amount is large, it can be uniformly mixed with the thermoplastic resin and easily injection molded. As described above, as a molding method in the production of the transparent resin molded product of the present invention, the injection molding method is a particularly preferable method in terms of excellent flexibility in shape and mass productivity.

  When triallyl isocyanurate is used, the blending amount when the thermoplastic resin is crosslinked is preferably 1 to 20% by weight based on the total amount of the molding material. By setting the blending amount within this range, it is possible to obtain a transparent resin molded article that has appropriate crosslinking, has excellent heat resistance and reflow heat resistance, and is more excellent in light resistance. Excellent injection moldability can be obtained. The invention of claim 9 contains 20% by weight or more of a thermoplastic resin composed of one or more resins selected from the group consisting of transparent polyamide and transparent fluororesin, and triallyl isocyanurate as a crosslinking aid. Compounding, molding, and molding a molding material containing 1 to 20% by weight, and, after the process, cross-linking the thermoplastic resin, all processes of compounding, injection molding and cross-linking are oxygen blocking It is the manufacturing method of the transparent resin molding characterized by the following. This manufacturing method facilitates injection molding by using the above-mentioned specific molding material. As a result, excellent shape freedom and mass productivity are achieved, and the transparent resin molding of the present invention can be easily obtained. It has the feature that it can be manufactured.

If the thermoplastic resin is composed only of a monomer having a main polarizability of 0.6 × 10 ⁻²³ or less, the photoelastic constant is increased and the birefringence due to molding or stress is increased, resulting in a clear image. The problem that it is difficult to obtain is less likely to occur. A monomer having a large molecular weight often has a different polarizability depending on the direction, but the “main polarizability” means the polarizability in the direction in which it becomes the largest.

  The invention according to claim 6 is the transparent resin molded article according to any one of claims 1 to 5, wherein the storage elastic modulus at 270 ° C. is 0.1 MPa or more. By setting the storage elastic modulus of the transparent resin molded body at 270 ° C. to 0.1 MPa or more, a satisfactory rigidity can be obtained from room temperature to a high temperature exceeding the reflow temperature. Therefore, the problem of thermal deformation hardly occurs even during reflow heating. More preferably, the storage elastic modulus at 270 ° C. is 1 MPa or more, and a more excellent molded body that hardly causes the problem of thermal deformation can be obtained.

  Here, the “storage elastic modulus” is one term (real term) constituting a complex elastic modulus representing the relationship between stress and strain when a sinusoidal vibration strain is applied to a viscoelastic body, and viscoelasticity measurement is performed. It is a value measured by a device (DMS). More specifically, it is a value measured at a rate of temperature increase of 10 ° C./min by a viscoelasticity measuring device by DVA-200 manufactured by IT Measurement Control Co., Ltd.

  The invention according to claim 7 is the transparent resin molded article according to claim 6, which contains a filler. By containing the filler in the transparent resin molded product, the amount of heating (heating temperature, time) and the amount of radiation required for the storage elastic modulus at 270 ° C. to be 0.1 MPa or more, particularly 1 MPa or more are reduced. be able to.

  In addition to the above, the transparent resin molded product of the present invention has other components such as antioxidants, ultraviolet absorbers, weathering stabilizers, copper damage, as long as the reflow heat resistance and optical properties are not impaired. An inhibitor, a flame retardant, a lubricant, a conductive agent, a plating imparting agent, and the like can be added.

  The invention according to claim 8 is an optical lens comprising the transparent resin molded body according to any one of claims 1 to 7. The transparent resin molded product according to any one of claims 1 to 7 is suitable for various optical members because it has excellent reflow heat resistance and optical characteristics. Among them, an Fθ lens for a laser beam printer, It can be suitably used as an optical lens such as an optical pickup lens, strobe Fresnel lens, LED lens or infrared communication lens.

  Further, the transparent resin molded article according to any one of claims 1 to 7 has excellent transparency and light resistance, and particularly excellent transparency to light having a wavelength of about 400 nm, and 100 Because it has high light intensity at a high temperature of about ℃ and light resistance that does not cause deterioration such as whitening even when irradiated for a long time, it is an optical lens used for optical pickups compatible with the Blu-ray method and a Fresnel lens for strobes using a xenon lamp For example, light having a shorter wavelength or light having a wider range of wavelengths can be suitably used as an optical lens that is irradiated with a large amount of light for a long time, and exhibits excellent effects.

  The transparent resin molded product of the present invention has excellent heat resistance, reflow heat resistance, excellent optical properties, and excellent light resistance. Therefore, the optical lens of the present invention comprising this transparent resin molded article also has excellent heat resistance, reflow heat resistance, optical characteristics, and light resistance, and is therefore suitably used as an optical member used in various small electronic devices. It is done.

  Embodiments of the present invention will be described below. Note that the present invention is not limited to the following embodiments. Various modifications can be made to the following embodiments within the same and equivalent scope as the present invention.

[About transparent polyamide]
The transparent polyamide used as the thermoplastic resin constituting the molding material of the transparent resin molding of the present invention can be obtained, for example, by condensing a diamine and a dicarboxylic acid. As the diamine used here,
Branched or unbranched aliphatic diamines having 6 to 14 C atoms, such as 1,6-hexamethylenediamine, 2-methyl-1,5-diaminopentane, 2,2,4- Trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,12-decamethylenediamine;
Cycloaliphatic diamines having 6 to 22 C atoms, such as 4,4′-diaminodicyclohexylmethane, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, 4,4′-diaminodicyclohexylpropane, 1 , 4-diaminocyclohexane, 1,4-bis (aminomethyl) -cyclohexane, 2,6-bis (aminomethyl) -norbornane, or 3-aminomethyl-3,5,5-trimethylcyclohexylamine;
Mention may be made of araliphatic diamines having 8 to 22 C atoms, such as m-xylylenediamine, p-xylylenediamine or bis (4-aminophenyl) propane.

In addition, as dicarboxylic acid,
Branched or unbranched aliphatic dicarboxylic acids having 6 to 22 C atoms, such as adipic acid, 2,2,4-trimethyladipic acid, 2,4,4-trimethyladipic acid, azelain Acid, sebacic acid, or 1,12-dodecanedioic acid;
Cycloaliphatic dicarboxylic acids having 6 to 22 C atoms, such as cyclohexane-1,4-dicarboxylic acid, 4,4′-dicarboxyldicyclohexylmethane, 3,3′-dimethyl-4,4′-dicarboxyldicyclohexyl Methane, 4,4′-dicarboxyldicyclohexylpropane, or 1,4-bis (carboxymethyl) cyclohexane;
Araliphatic dicarboxylic acids having 8 to 22 C atoms, such as 4,4′-diphenylmethanedicarboxylic acid;
Aromatic dicarboxylic acids having 8 to 22 C atoms, such as isophthalic acid, tributylisophthalic acid, terephthalic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2 , 7-naphthalene dicarboxylic acid, diphenic acid, or diphenyl ether-4,4′-dicarboxylic acid.

The transparent polyamide usable in the present invention can also be obtained by ring-opening polymerization of lactam or condensation of ω-aminocarboxylic acid. As a raw material monomer used at this time,
A lactam having 6 to 12 C atoms or the corresponding ω-aminocarboxylic acid, ε-caprolactam, ε-aminocaproic acid, capryllactam, ω-aminocaprylic acid, ω-aminoundecanoic acid, lauric lactam, or ω-amino And dodecanoic acid.

As a more specific example of the transparent polyamide that can be used in the present invention,
A polyamide comprising terephthalic acid and an isomer mixture of 2,2,4-trimethylhexamethylenediamine and 2,4,4-trimethylhexamethylenediamine;
A polyamide comprising isophthalic acid and 1,6-hexamethylenediamine,
A copolyamide comprising terephthalic acid / isophthalic acid and 1,6-hexamethylenediamine,
A copolyamide comprising isophthalic acid, and 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, and lauric lactam or caprolactam;
(Co) polyamides consisting of 1,12-dodecanedioic acid or 1,10-dodecanedioic acid and 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, optionally further lauric lactam or caprolactam,
A copolyamide comprising isophthalic acid and 4,4′-diaminodicyclohexylmethane and lauric lactam or caprolactam;
A polyamide comprising 1,12-dodecanedioic acid and 4,4′-diaminodicyclohexylmethane,
Mention may be made of a terephthalic acid / isophthalic acid mixture, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, and a copolyamide composed of lauric lactam.

  The transparent polyamide that can be used in the present invention may be a blend of various types of polyamides. If the blend itself is transparent, the blend components may contain crystalline ones. As a specific product example of transparent polyamide, transparent nylon 12 (trade names Grillamide TR-55, TR-90 (manufactured by Ms. Chemie Japan)) and the like can be mentioned. These transparent polyamides are preferable because they are excellent in light resistance and are less likely to cause discoloration or deformation against xenon emission. Here, TR-90 is a condensation polymer of 1,10-decanedicarboxylic acid and 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, and as mentioned above, is a particularly preferred transparent polyamide.

[About transparent fluororesin]
Examples of PVdF include those sold under the trade name of Kyner 2801 made by Arkema, THV220 made by 3M, and RPFE made by Daikin RP4020 as THV. Of these, Kyner 2801 is preferable because it has low crystallinity and is transparent.

[Crosslinking aid]
As the crosslinking aid, in addition to triallyl isocyanurate, oximes such as p-quinone dioxime and p, p′-dibenzoylquinone dioxime; ethylene dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, Acrylate or methacrylates such as cyclohexyl methacrylate, acrylic acid / zinc oxide mixture, allyl methacrylate; vinyl monomers such as divinylbenzene, vinyltoluene, vinylpyridine; hexamethylene diallyl nadiimide, diallyl itaconate, diallyl phthalate, diallyl isophthalate, Allyl compounds such as diallyl monoglycidyl isocyanurate and triallyl cyanurate; N, N′-m-phenylenebismaleimide, N, N ′-(4,4′-methyl) Examples include maleimide compounds such as (di-phenylene) dimaleimide, but triallyl isocyanurate provides excellent injection moldability even when the blending amount is large, and also exhibits excellent crosslinking promotion effect even with a small blending amount. Therefore, it is preferable. One type of crosslinking aid may be used alone or in combination.

[About filler]
As the filler, it is desirable to use a so-called transparent filler having a refractive index close to that of the resin in order not to impair the transparency of the molded body. A transparent glass fiber is mentioned as an example of a transparent filler. The addition amount is preferably 0.1 to 50 parts by weight, more preferably 1 to 50 parts by weight, based on 100 parts by weight of the resin. In addition, a filler having a particle diameter equal to or smaller than the wavelength of light, fumed silica, a nanometal filler, or a nanocomposite filler can also be used. An example of the organic filler may include bionanofiber (Kyoto University).

  By setting the filler content to 0.1 parts by weight or more, it is easy to obtain excellent reflow heat resistance and rigidity even when the heating amount and the irradiation amount of electron beam are reduced. It is easy to reduce the occurrence of problems such as coloring and brittleness of the molded body. When the filler content exceeds 50 parts by weight, the resulting molded product tends to be brittle or the transmittance tends to decrease.

Examples 1-5 and Comparative Examples 1-3
(1) First, the raw materials used in the production of the transparent resin moldings of Examples and Comparative Examples will be described.
[Crosslinkable thermoplastic resin]
・ Grillamide TR-90: Transparent polyamide resin: manufactured by Ms. Chemie Japan, Inc. (in the table, indicated as “TR90”)
Tg = 155 ° C., average transmittance at 600 to 1000 nm (thickness 2 mm) 91%
-Kyner 2801: Polyvinylidene fluoride (PVdF): manufactured by Arkema Inc.-THV220: Tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV): manufactured by 3M

[Crosslinking aid]
・ Triallyl isocyanurate: manufactured by Nippon Kasei Co., Ltd. (indicated as “TAIC” in the table)
Dipropylene glycol diacrylate: manufactured by Shin-Nakamura Chemical Co., Ltd. (denoted as “DPGD” in the table)

(2) Manufacture of transparent resin moldings The raw materials shown in the blending prescription column of Table 1 were mixed with a blender based on the prescription shown in Table 1 (all are parts by weight) and then a twin screw extruder (TEM58BS, Toshiba Machine) And mixed with heating to produce compounded pellets (molding material). Thereafter, except for Comparative Example 3, injection molding was performed by an injection molding machine (SE-185, manufactured by Sumitomo Heavy Industries) under a nitrogen atmosphere to obtain a plate of 5 cm × 7 cm × 2 mm thickness. The injection moldability was determined based on whether this injection molding was possible stably. The results are shown in Table 1.

  After injection molding, the molded plate was irradiated with an electron beam having a dose shown in the electron beam irradiation amount column of Table 1 in a nitrogen atmosphere except for Comparative Example 3, and the thermoplastic resin constituting the plate was crosslinked, A test sample of a transparent resin molding was produced. In addition to Comparative Example 3, not only the above-described injection molding and electron beam irradiation, but also mixing in a blender and mixing in a twin-screw extruder were performed in a nitrogen atmosphere, and more specifically for industrial use with a purity of 99.95%. Performed under a flow of nitrogen gas. On the other hand, in Comparative Example 3, the flow of nitrogen gas was not performed, but mixing in a blender, mixing in a twin screw extruder, injection molding, and electron beam irradiation were performed in the atmosphere, that is, in the presence of oxygen. About the produced sample, the reflow heat resistance, the total transmittance | permeability, and the storage elastic modulus (270 degreeC) were measured with the following method. The measurement results are shown in Table 1.

[Total transmittance]
For the sample (thickness 2 mm) after heating at 200 ° C. for 10 minutes, the total light transmittance was measured within the range of 400 nm to 1000 nm.

[Storage modulus]
It is the storage elastic modulus in 270 degreeC measured at the temperature increase rate of 10 degree-C / min with the viscoelasticity measuring device by ITA measurement control company DVA-200 about the sample after heating at 200 degreeC for 10 minutes.

[Reflow heat resistance]
The sample was left in a constant temperature bath at 260 ° C. for 1 minute, and the presence or absence of deformation was evaluated based on the following criteria.
○: Not deformed.
Δ: Deforms but maintains shape.
X: It melts completely.

  In Table 1, “injection moldability” means that the crosslinkable thermoplastic resin and the crosslinking aid are uniformly mixed and stable injection molding can be performed. An injection moldability of x means that the crosslinking aid is not uniformly mixed with the thermoplastic resin, and the liquid of the crosslinking aid and resin pellets are mixed. For this reason, pellets cannot be plasticized stably and cannot be injection molded. The injection moldability is Δ when the liquid of the crosslinking aid is partially mixed with the resin pellets, but stable injection molding can be performed.

As shown in the results of Table 1, when a molding material mainly composed of transparent polyamide or transparent fluororesin is used and the crosslinking aid is TAIC (Examples 1 to 4 and Comparative Example 3), the blending amount is Even in the case of about 2% by weight, excellent injection moldability is obtained, and excellent reflow heat resistance, total transmittance, and storage elastic modulus are also obtained. However, in Example 2 in which the blending amount of TAIC is 50% by weight, the injection moldability is slightly lowered. When the molding material is mainly composed of transparent polyamide and the crosslinking aid is DPGD (Example 5), although excellent injection moldability and transmittance can be obtained, the storage elastic modulus and reflow heat resistance are low. From comparison of this result and the result of Example 1, it is clear that TAIC is preferable as a crosslinking aid in order to obtain excellent storage elastic modulus and reflow heat resistance. Further, Comparative Example 1 in which the blending amount of DPGD is 20% by weight has poor injection moldability and cannot be injection molded. Comparison of this result and the result of Example 2 shows that TAIC is preferable to DPGD as a crosslinking aid in order to obtain excellent injection moldability. Even in Comparative Example 2 where the blending amount of the transparent polyamide is less than 20% by weight, the injection moldability is poor and injection molding cannot be performed.
Comparative Example 3 has the same formulation and electron beam irradiation conditions as Example 3, but as a result of mixing in a blender, mixing in a twin screw extruder, injection molding, and electron beam irradiation in the atmosphere, The total transmittance is also less than 80%, and the molded product is yellowed.

Claims (9)

A molding material containing 20% by weight or more of a thermoplastic resin, compounded and molded, and a transparent resin molded body obtained by crosslinking the thermoplastic resin,
A transparent resin molded product characterized in that when the molded product is 2 mm thick and heated at 200 ° C. for 10 minutes, the light transmittance is 80% or more over the entire wavelength range of 400 to 1000 nm.   The said thermoplastic resin is 1 type, or 2 or more types of resin chosen from the group which consists of transparent polyamide and transparent fluororesin, The transparent resin molding of Claim 1 characterized by the above-mentioned.   The transparent resin molded article according to claim 2, wherein the transparent polyamide comprises a condensation polymer of 1,10-decanedicarboxylic acid and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane.   Transparent fluororesins include polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and polymer blends thereof. The transparent resin molded product according to claim 2, which is selected from the group consisting of:   The molding material further contains triallyl isocyanurate as a crosslinking aid, and the compounding, molding, and crosslinking of the thermoplastic resin are performed under oxygen shielding. 5. The transparent resin molded product according to any one of 4 above.   The transparent resin molded body according to any one of claims 1 to 5, wherein the transparent resin molded body has a storage elastic modulus at 270 ° C of 0.1 MPa or more.   The transparent resin molded body according to claim 6, wherein the transparent resin molded body contains a filler.   An optical lens comprising the transparent resin molded body according to any one of claims 1 to 7.   Contains 20% by weight or more of a thermoplastic resin composed of one or more resins selected from the group consisting of transparent polyamide and transparent fluororesin, and contains 1 to 20% by weight of triallyl isocyanurate as a crosslinking aid. A molding material is compounded and injection-molded, and after the step, the thermoplastic resin is crosslinked, and all the compounding, injection molding, and crosslinking steps are performed under the shielding of oxygen. A method for producing a transparent resin molded product.