JPH0940731A - UV curable resin composition for Fresnel lens and transmission screen - Google Patents

Abstract

(57) [Summary] [Structure] Aromatic epoxy acrylate, urethane acrylate containing bisphenol A ethylene oxide adduct as a diol component, aromatic monofunctional acrylate, lauryl alcohol ethylene oxide adduct and phosphoric acid monoester, and photopolymerization initiation. A UV-curable resin composition for a Fresnel lens containing an agent as an essential component; and a transmission screen having a Fresnel lens produced by curing the composition on a substrate. [Effect] Excellent adhesion to the substrate containing methyl methacrylate as the main component, easy molding, and the cured resin is
It has a high refractive index, is tough, and has excellent chemical resistance, heat resistance, cold resistance, and antistatic properties, and is extremely useful as a material for Fresnel lenses. Further, the transmissive screen having a Fresnel lens produced by curing the resin composition has good handleability, and since the refractive index is high, it is possible to make a projection television with a large screen size thin and compact. It is useful.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet curable resin composition having an antistatic property suitable for manufacturing optical parts such as Fresnel lenses. More specifically, the adhesiveness to a substrate containing a methyl methacrylate polymer or a copolymer of methyl methacrylate and another (meth) acrylate (hereinafter referred to as "methyl methacrylate (co) polymer") as a main component The present invention relates to an ultraviolet curable resin composition having excellent antistatic ability, and a transmissive screen having a Fresnel lens sheet provided with a Fresnel lens made of the ultraviolet curable resin composition.

[0002]

2. Description of the Related Art Conventionally, a Fresnel lens sheet is manufactured by a method of pouring an ultraviolet curable resin composition between a mold and a transparent resin substrate and irradiating it with ultraviolet rays to cure the resin. Recently, a resin having a high refractive index has been required in accordance with the need for a thinner projection television, and various proposals have been made (Japanese Patent Laid-Open No. Hei 5).
-65318, JP-A-5-155944,
JP-A-5-247156, JP-A-5-28703
No. 7). However, the lenses obtained from these UV-curable resin compositions have a problem in that surrounding dust and the like adhere due to static electricity due to charging, and in order to solve this problem, the cured product has an anti-UV-curable resin composition. Have been proposed (JP-A-1-302201 and JP-A-3-302201).
157412).

[0003]

However, these compositions have poor adhesion to a substrate containing a methyl methacrylate (co) polymer as a main component, and a primer is used on the substrate side in order to improve the adhesion. It was not possible to obtain a lens having required adhesion, refractive index, scratch resistance, and antistatic property.

[0004]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of these problems, and as a result, a resin composition comprising a specific monomer, a urethane (meth) acrylate and a phosphoric acid ester has the above performance. The inventors have found that they are satisfied and have reached the present invention. That is, the present invention provides a UV-curable resin composition for forming a Fresnel lens on a substrate containing a methyl methacrylate polymer or a copolymer of methyl methacrylate and another (meth) acrylate as a main component. ) To (E) as essential components, an ultraviolet-curable resin composition for Fresnel lens; (A): hydroxyl group-containing (meth) acrylate (B): diol represented by the following general formula (1) Urethane (meth) acrylate containing (b) as an essential component

[0005]

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[In the formula, R ¹ , R ² and R ³ each represent a hydrogen atom or a methyl group, m and n each represent an integer of 1 to 15, and (m + n) represents an integer of 2 to 20. ] (C): Aromatic ring-containing monofunctional (meth) acrylate (D): Phosphate ester represented by the following general formula (2)

[0007]

Embedded image

[In the formula, R represents an alkyl group having 5 to 16 carbon atoms, m is an integer of 1 to 4, and n is 1 or 2. ] (E): A transmissive screen comprising a Fresnel lens sheet provided with a Fresnel lens made of a resin obtained by curing the composition and a photopolymerization initiator.

In the present invention, the hydroxyl group- and aromatic ring-containing (meth) acrylate (A) includes 2-hydroxy-3-phenoxypropyl (meth) acrylate and 2-hydroxy-3-phenoxypropyl (meth) acrylate.
Hydroxy-3- (2'-, 3'- and 4'-methylphenoxy) propyl (meth) acrylate, phthalic acid [(meth) acryloyloxyethyl- (meth) acryloyloxy-2-hydroxypropyl] ester, bisphenol Class (bisphenol A, bisphenol F,
(Meth) acrylate adducts of glycidyl ethers such as bisphenol S). Of these, preferred are low-viscosity 2-hydroxy-3-phenoxypropyl (meth) acrylate and 2-hydroxy-3- (2 '-, 3'- or 4'-methylphenoxy) propyl (meth) acrylate. is there.

In the present invention, the urethane acrylate (B) is the diol (b) represented by the general formula (1).
And / or a reaction product of a polyester diol comprising (b) and a dicarboxylic acid, an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate. M and n in the general formula (1) are each an integer of 1 to 15, preferably an integer of 1 to 7, and (m + n) is an integer of 2 to 20, preferably an integer of 2 to 10.
When (m + n) is less than 2, the lens obtained by curing the composition does not exhibit antistatic properties, and when it exceeds 20, the refractive index of the cured product becomes low.

The above-mentioned (b) is a compound obtained by adding alkylene oxide to bisphenols. Examples of bisphenols include bisphenol A, bisphenol F, bisphenol AD and the like. Examples of the alkylene oxide include ethylene oxide (hereinafter referred to as EO).
Abbreviated), propylene oxide (hereinafter abbreviated as PO),
A combination of EO and PO (random adduct and block adduct) and the like can be mentioned. As a method for adding alkylene oxide to bisphenols, a known method, for example, a method for adding EO and / or PO to bisphenols in the presence of an alkali catalyst can be exemplified.

The above polyester diol can be produced from (b) and a dicarboxylic acid under known esterification conditions. When producing polyester diol (hydroxyl group /
The equivalent ratio of (carboxyl group) is usually 2.0 to 1.05,
It is preferably 2.0 to 1.5.

Examples of the dicarboxylic acid constituting the polyester diol include maleic acid, fumaric acid, succinic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid and the like, and acid anhydrides thereof. Of these, preferred are maleic acid, fumaric acid, succinic acid and adipic acid.

As the diol constituting (B), (b)
And / or other diol can be used in combination with the polyester diol comprising the (b) and the dicarboxylic acid, if necessary. The other diol preferably has a molecular weight of 400 or less. Molecular weight 400
Use of a diol in excess of 10 significantly lowers the refractive index and is not preferred. As the other diol,
Ethylene glycol, propylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,4-butanediol, 1,6-hexanediol, polyethylene glycol (degree of polymerization 2-9), polypropylene glycol (degree of polymerization) 2 to 6), polycaprolactone diol (polymerization degree 2 or 3) and the like. When used in combination, the amount of the other diol used is usually 30% by weight or less, preferably 10% by weight or less, based on the weight of (b) contained in (B).

The organic polyisocyanate constituting (B) is, for example, 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and modified products thereof (carbodiimide, uretdione, burette, isocyanurate and other modified products) Products) and mixtures thereof. Of these, particularly preferred are 2,4-tolylene diisocyanate and 2,6-
Tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and mixtures of two or more thereof.

As the hydroxyl group-containing (meth) acrylate constituting (B), 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-
Examples thereof include hydroxy-3-butoxypropyl (meth) acrylate and 2-hydroxy-3-phenoxypropyl (meth) acrylate. Among these, preferred are 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.

The method for producing (B) is not particularly limited, but for example, a polyester diol consisting of (b) and / or (b) and a dicarboxylic acid and an organic polyisocyanate are reacted by a known method used for ordinary urethanization reaction. ,
Next, a method of reacting with a hydroxyl group-containing (meth) acrylate can be exemplified.

The number average molecular weight of (B) is usually 2,000.
To 10,000, preferably 3,000 to 8,000
It is. When the number average molecular weight is less than 2,000, sufficient flexibility cannot be obtained, and when the number average molecular weight exceeds 10,000, the viscosity of the resin composition becomes high, and bubbles remain in the molded product to impair the lens function, which is not preferable. The refractive index (25 ° C.) of (B) is usually 1.52 or more, preferably 1.53 or more.

In the present invention, the aromatic ring-containing monofunctional (meth) acrylate (C) includes phenyl (meth) acrylate, benzyl (meth) acrylate, phenol EO and / or PO adduct (EO and / or PO adduct). (Meth) acrylate having an addition mole number of 1 to 6), EO and / or PO adduct of nonylphenol (the addition mole number of EO and / or PO is 1 to 6), EO of dodecylphenol and / or Alternatively, a (meth) acrylate of a PO adduct (the number of moles of EO and / or PO added is 1 to 6) may be used. Among these, preferred are (meth) acrylates of EO and / or PO adducts of phenol (the number of moles of EO and / or PO added is 1 to 6), and EO and / or PO adducts of nonylphenol (EO and / or PO). Alternatively, the number of moles of PO added is 1 to 6) (meth) acrylate and a mixture thereof.

In the present invention, (A) :( B) :( C)
The weight ratio is usually (20-60) :( 10-50):
(5 to 50), preferably (30 to 50): (20 to 4)
0): (10-40). If the ratio of (A) is less than 20, the adhesion to the substrate will be poor, and if it exceeds 60, the viscosity will be low, and bubbles will be entrained during molding, impairing the lens function, which is not preferable. When the ratio of (B) is less than 10, the cured product does not exhibit flexibility and the scratch resistance is deteriorated, and when it exceeds 50, the viscosity of the resin composition becomes high, and bubbles remain in the molded product to cause a lens function. Spoil. If the ratio of (C) is less than 5, the viscosity will be high, and if it exceeds 50, the adhesion to the substrate will be poor.

In the present invention, phosphoric acid ester (D)
Is a compound represented by the general formula (2). R in the general formula (2) is an alkyl group having 5 to 16 carbon atoms, n is an integer of 1 to 4, and m is 1 or 2.
When the carbon number of R is out of this range, sufficient antistatic property is not exhibited. When n is 0, it does not dissolve in the composition of the present invention, or (D) is precipitated during storage even if dissolved, and when it is 5 or more, sufficient antistatic properties are not exhibited. When m is 0 (D)
Does not dissolve in the composition of the present invention, and 3 does not exhibit antistatic properties at all.

(D) is an aliphatic alcohol (having 5 to 5 carbon atoms).
It is produced by adding EO to 16) by a known method and further reacting it with phosphoric acid or a derivative thereof (diphosphorus pentaoxide, etc.).

The above alcohol is a linear or branched monoalcohol having 5 to 16 carbon atoms. Among these, preferred are n-hexyl alcohol, n-octyl alcohol, 2-ethylhexyl alcohol and n-lauryl alcohol.

In the present invention, the amount of (D) used is usually 0.1 to 2.0% by weight based on the total weight of the resin composition,
It is preferably 0.3 to 1.5% by weight. The amount used is 0.
If it is less than 1% by weight, the antistatic property is insufficient, and
If the content is more than wt%, the adhesion to the substrate will decrease.

In the composition of the present invention, the components (B) and (D) each have an antistatic property independently,
The antistatic property is insufficient when (B) is used alone, and the compounding amount is increased in order to obtain sufficient antistatic property when (D) is used alone, resulting in impaired adhesion. (B) and (D)
When used together, the antistatic property is improved and the target performance of the present invention can be obtained. (D) also functions as a component that improves the scratch resistance of the cured product.

In the present invention, other (meth) acrylate monomers can be used in combination with (A), (B) and (C) if necessary. When used in combination, the content of the other (meth) acrylate is usually 30% by weight or less, preferably 20% by weight or less, based on the total weight of (A), (B) and (C).

Specific examples of the other (meth) acrylate monomers include tetrahedfurfuryl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, glycidyl ( (Meth) acrylate,
Isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth)
Acrylate, 2-hydroxy-3-butoxypropyl (meth) acrylate, ethylene glycol di (meth)
Acrylate, 1,2- and 1,3-propylene diacrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, bisphenols (bisphenol A, (Bisphenol F, bisphenol S, etc.) and their alkylene oxide adducts di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, alkylene oxide modified Trimethylolpropane tri (meta)
Examples thereof include acrylate, alkylene oxide-modified pentaerythritol tetra (meth) acrylate, alkylene oxide-modified dipentaerythritol hexa (meth) acrylate, and the like.

Examples of the photopolymerization initiator (E) in the present invention include benzoin alkyl ether, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one and benzophenone. , Methyl benzoyl formate, isopropyl thioxanthone, and mixtures of two or more thereof.

The amount of (E) used is usually 0.1 to 10% by weight, preferably 0.5, based on the total weight of the resin composition.
~ 6% by weight.

If necessary, the composition of the present invention contains a thermal polymerization inhibitor, a defoaming agent, a leveling agent, a coupling agent,
Known additives such as antistatic agents and ultraviolet absorbers can be added.

The viscosity of the composition of the present invention is usually 500 to 5,000 cps at the coating temperature. If the viscosity at the time of coating is out of this range, bubbles will remain in the molded product, impairing the lens function.

The refractive index (25 ° C.) of the cured product of the composition of the present invention is usually 1.54 or more, preferably 1.55.
That is all. The surface resistance value of the cured product is usually 10
^{It is 13} Ω or less, preferably 10 ¹² Ω or less. As described above, the composition of the present invention can have a cured product having a refractive index of 1.54, preferably 1.55. Therefore, when a Fresnel lens sheet is produced, a sufficiently short focus can be achieved.
Further, since the antistatic property is imparted, static electricity is not generated during the assembly of the lens sheet, so that dust or the like is not attached and the workability is improved.

The composition of the present invention can be cured by irradiation with ultraviolet rays. The ultraviolet irradiation device is not particularly limited, and examples thereof include a high pressure mercury lamp and a metal halide lamp.

FIG. 1 is a sectional view showing an example of the transmission screen of the present invention. As shown in FIG. 1, the transmissive screen of the present invention comprises a Fresnel lens sheet 2 having a Fresnel lens 5 obtained by curing the above-mentioned UV curable resin composition for Fresnel lens on a light exit surface of a substrate 6, A lenticular lens is arranged on both the light output surface and the light output surface, and the non-light-collecting portion (non-light-emitting portion) is formed on the light output surface by collecting the projection light by the lenticular lens on the light input surface.
The lenticular lens sheet 3 having the light absorption layer 4 is arranged in combination so that the Fresnel lens 5 of the Fresnel lens sheet 2 and the lenticular lens on the light incident surface side of the lenticular lens sheet 3 face each other. Here, in the Fresnel lens sheet 2, the Fresnel lens 5 is formed directly from the resin composition without providing an adhesion imparting component layer such as a primer layer on the substrate 6. The transmissive screen 1 of the present invention is characterized by having a Fresnel lens sheet 2 provided with a Fresnel lens 5 obtained by curing the above-mentioned ultraviolet curable resin composition, and the lenticular lens shown in FIG. In addition to the combination with the lens sheet 3, the lens sheet 3 may be arbitrarily combined with another screen lens sheet according to the purpose.

The substrate 6 containing a methyl methacrylate (co) polymer constituting the Fresnel lens sheet as a main component is a homopolymer of methyl methacrylate or methyl methacrylate and another alkyl (meth) acrylate (carbon of alkyl). The main component is a copolymer with the formulas 1 to 18). The content of the methyl methacrylate component in the substrate is usually 70% by weight or more, preferably 80% by weight or more. The content of methyl methacrylate component is 7
If it is less than 0% by weight, the adhesion of the composition of the present invention to the cured product is deteriorated, which is not preferable.

The above-mentioned methyl methacrylate-based (co)
As the substrate 6 containing a polymer as a main component, a plate having a thickness of 0.5 to 5 mm formed by a known method such as injection molding, extrusion molding or cast molding is used.

In order to produce the Fresnel lens sheet 2 in the present invention, the composition of the present invention is applied to a Fresnel lens molding die so that air does not enter the substrate 6 from the above coated resin. The sheets are stacked under pressure, irradiated with ultraviolet rays to cure the ultraviolet curable resin, and then the sheet is peeled from the mold.

[0038]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. “Parts” in the examples indicates parts by weight.

Synthesis Examples 1 and 2 The urethane acrylate (U-1) of the present invention was synthesized by the following synthesis method according to (b), (B1), (B2), (B3) and their compounding ratio (weight ratio) shown in Table 1. And U-2) were obtained. Refractive index of the obtained urethane acrylate (25 ° C)
Was measured using an Abbe refractometer (manufactured by Atago). The results are shown in Table 1.

(Synthesis Method) A four-necked flask equipped with a stirrer, a condenser and a thermometer was charged with a specified amount of diol (b), a specified amount of dicarboxylic acid (B1) and 0.025 part of dibutyltin oxide. The dehydration esterification reaction was carried out under the conditions of 10 mmHg and 200 ° C. for 8 hours. A specified amount of the organic polyisocyanate (B2) was added to the obtained polyester and reacted at 80 to 90 ° C. for 2 hours, and then a specified amount of hydroxyethyl acrylate (B3) was added and the mixture was added to 80 to 90.
Urethane acrylate was obtained by reacting at 3 ° C for 3 hours.

Synthesis Example 3 558 parts of lauryl alcohol were placed in an autoclave equipped with a stirrer, a condenser and a thermometer, and 264 parts of ethylene oxide was injected at 50 ° C., followed by reaction at 200 ° C. for 2 hours. To 822 parts of the obtained alcohol, 137 parts of diphosphorus pentaoxide was added and reacted at 80 to 90 ° C. for 2 hours to obtain a phosphoric acid ester (D-1).

Synthetic Example 4 520 parts of octyl alcohol was placed in the same apparatus as in Synthetic Example 3 and 176 parts of ethylene oxide was reacted at 50 ° C., and then 280 parts of diphosphorus pentaoxide was reacted to prepare a phosphoric ester (D-2). ) Got.

Comparative Synthesis Example 1 400 parts of lauric acid was placed in a four-necked flask equipped with a stirrer, a condenser and a thermometer, 300 parts of triethanolamine was added at room temperature, and the mixture was allowed to react at room temperature for 2 hours to give lauric acid. And a salt of triethanolamine (D-3) were obtained.

[0044]

[Table 1] In the table, EO indicates ethylene oxide and PO indicates propylene oxide.

Examples 1 to 5 Compounding was carried out according to the compounding ratio (weight ratio) shown in Table 2 to obtain resin compositions of the present invention (Examples 1 to 5). 35 ° C for each
The viscosity was measured with a BL type viscometer (manufactured by Tokyo Keiki Co., Ltd.). In addition, adjusting the film of 50μ, ultraviolet rays 1000mJ
/ Cm ^{2 After} irradiation to obtain a cured product, the refractive index at 25 ° C was measured. Table 3 shows the viscosity at 35 ° C. and the refractive index of the cured product.

Comparative Examples 1 to 3 Compounding was carried out according to the compounding ratio (weight ratio) shown in Table 2 to obtain comparative resin compositions (Comparative Examples 1 to 3). Table 3 shows the viscosity at 35 ° C. and the refractive index of the cured product.

Test Example A Fresnel lens was prepared from each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 according to the following test method, and adhesion to a substrate, releasability from a mold, scratch resistance, and electrification. A preventive test was conducted. The results are shown in Table 3.

(Test Method) The resin composition shown in Table 2 was adjusted to a temperature of 35 ° C. and applied to a Fresnel lens mold (50 cm × 50 cm) preliminarily plated with chrome to a thickness of 50 to 150 μm using a dispenser, A 2 mm thick substrate made of methyl methacrylate copolymer (“SUMIPEX HT” manufactured by Sumitomo Chemical Co., Ltd.) is pressure-laminated on the resin filled in the mold so that air does not enter, and a high pressure mercury lamp is used. After irradiating ultraviolet rays at 1,000 mJ / cm ² to cure the ultraviolet curable resin, the mold was peeled off to obtain a Fresnel lens sheet. The releasability at the time of mold release and the performance of the obtained Fresnel lens were evaluated by the following methods. Releasability: Difficulty of release from the mold when manufacturing Fresnel lens Evaluation criteria ○; Easy to release from the mold ×; Difficult to release from the mold and deforms during release Bubble bite: Presence or absence of air bubbles in Fresnel lens Evaluation criteria ○; No air bubbles ×; There are air bubbles Adhesion: Adhesion between cured UV curable resin composition and substrate Putting a grid (10 × 10) in 1 mm width with a knife , Stick cellophane tape and peel 90 degrees. At this time, peeling of the cured resin from the substrate was observed. Evaluation Criteria ◯: No peeling ×: Peeling Scratch resistance: Ease of scratching Fresnel lens Evaluation Criteria ◯: No marks left when scratched with nails X: Marks left when scratched with nails Antistatic properties Adjusted to a temperature of 25 ℃ and humidity of 60%, ULTRA HIG
The surface resistance value was measured with H RESISTANCE METER (manufactured by Advantest).

[0049]

[Table 2] Aronix M5700: 2-Humanoxy-3-phenoxypropyl acrylate, Toagosei Co., Ltd. Aronix M101: Phenoxyethylene ethylene glycol acrylate, Toagosei Aronix M111: Nonylphenoxyethylene glycol acrylate, Toagosei NK ester A-400: Polyethylene glycol Acrylate, Shin-Nakamura Chemical Co., Ltd. VISCOAT 195: 1,4-Butanediol acrylate, Osaka Organic Chemical Co., Ltd. Darocur 1173: 2-Hydroxy-2-methyl-1-phenylpropan-1-one, Ciba Geigy Co.

[0050]

[Table 3]

[0051]

The ultraviolet curable resin composition for Fresnel lenses of the present invention has the following effects. (1) Excellent adhesion to a substrate containing a methyl methacrylate polymer or a copolymer of methyl methacrylate and another (meth) acrylate as a main component. (2) It is easy to mold an optical component such as a Fresnel lens. (3) The cured resin has a high refractive index of 1.54 or more,
Excellent chemical resistance, toughness, heat resistance and cold resistance.
(4) The cured resin has excellent antistatic properties. The composition of the present invention is extremely useful especially as a material for a Fresnel lens because it exhibits the above effects. Since the transmissive screen of the present invention has a Fresnel lens sheet obtained by curing the ultraviolet curable resin composition for Fresnel lenses described above, it has a Fresnel lens surface excellent in scratch resistance of the surface, and the transmissive screen is transported. It will not be damaged even if it comes into contact with other lens sheets during or during assembly, and there is no need to perform surface treatment such as applying silicone oil or the like between the Fresnel lens sheet and the lenticular lens sheet. Further, the transmission screen of the present invention has a Fresnel lens surface having excellent antistatic performance, does not adhere to dust and the like during assembly of the transmission screen, and improves the workability of an operator. Further, since the transmissive screen of the present invention has a high refractive index of 1.54 or more, it is possible to form a short focus Fresnel lens to shorten the distance between the transmissive screen and the projection light source. The TV can be made thinner and smaller.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a transmissive screen of the present invention.

[Explanation of symbols]

 1 Transmissive screen 2 Fresnel lens sheet 3 Lenticular lens 5 Fresnel lens 6 Substrate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tsutomu Yamashita Tsutomu Yamashita 1-11 Hitotsubashi-honcho, Higashiyama-ku, Kyoto Sanyo Kasei Kogyo Co., Ltd. Within the corporation

Claims (3)

[Claims] 1. An ultraviolet curable resin composition for forming a Fresnel lens on a substrate containing a methyl methacrylate polymer or a copolymer of methyl methacrylate and another (meth) acrylate as a main component, wherein )
An ultraviolet-curable resin composition for a Fresnel lens, containing (E) as an essential component. (A): Hydroxyl group- and aromatic ring-containing (meth) acrylate (B): Urethane (meth) acrylate containing diol (b) represented by the following general formula (1) as an essential constituent: [In the formula, R ¹ , R ² and R ³ each represent a hydrogen atom or a methyl group, m and n each represent an integer of 1 to 15, and (m + n) represents an integer of 2 to 20. ] (C): Aromatic ring-containing monofunctional (meth) acrylate (D): Phosphate ester represented by the following general formula (2) [In the formula, R represents an alkyl group having 5 to 16 carbon atoms, m represents an integer of 1 to 4, and n represents 1 or 2. ] (E): Photopolymerization initiator 2. The weight ratio of (A) :( B) :( C) is
The resin composition according to claim 1, which is (20-60) :( 10-50) :( 5-50). 3. A Fresnel lens comprising a resin obtained by curing the composition according to claim 1 or 2 on a substrate containing a methyl methacrylate polymer or a copolymer of methyl methacrylate and another (meth) acrylate as a main component. A transmissive screen having a Fresnel lens sheet provided with.