JPH04254801A - Optical element - Google Patents

Abstract

PURPOSE:To provide an optical element which is easy in manufacturing and is not restricted in relation to a product shape because a mold releasing property thereof is excellent without applying a mold releasing agent to a molding die, and in which bleeding, peeling-off of a coating film, and clouding are not generated. CONSTITUTION:A resin layer is formed of an ultraviolet-setting resin comprising urethane denaturated (meta) acrylate and (meta) acrylate being monomer components, containing organic phosphoric ester or salt thereof, organic phosphorous ester and hydroxyalkylamine by 0.005-1.0wt.% in whole volume, on a glass base material.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an optical element having a resin layer of a desired shape on the surface of a molded product base material by pouring a fluid raw material such as resin or rubber into a mold and curing it with ultraviolet rays. .

0002

[Prior Art] Conventionally, in a molding method for manufacturing a molded product having a resin layer having a desired shape by curing an ultraviolet curable resin on a base material such as glass, resin monomers are polymerized and cured in a mold. The subsequent release from the mold is done by heat shock method, ultrasonic demolding method, or mechanical separation method because the resin surface adheres or adheres to the mold surface and it is difficult to release the molded product. Ta.

[0003] Furthermore, the mold in contact with the resin layer is made of glass,
It is made from materials such as metals, metal oxides, or alloys. The surface of these molds is covered with oxides in the air, and water molecules and organic compound molecules bond to the surface.
It is thought that it is adsorbed. Since this bond/adsorbent forms bonds such as hydrogen bonds with polar groups such as carboxyl groups, cyano groups, and amino groups in the resin,
The adhesive force between the mold and the resin layer was strong, causing defective products due to resin remaining on the mold. Therefore, in order to weaken the adhesive force between the mold and the resin layer and improve mold release properties, mold release agents such as fluororesin, silicone resin, and ester-based surfactants have been applied.

0004

[Problems to be Solved by the Invention] However, in the heat shock method, the molded product may be deformed or heated due to repeated cooling and heating.
There were problems such as deterioration and cracking. The problem with the ultrasonic demolding method is that molded products often crack, resulting in a low yield rate. In addition, mechanical separation can cause deformation of the molded product because a large force is applied to a part of the molded product, and the molded product must be tapered to make it easier to remove it from the mold. There was a problem in that the shape of the molded product was restricted.

[0005] In addition, a method of improving mold releasability by applying a mold release agent such as a fluororesin, silicone resin, or fatty acid ester to the mold in contact with the resin layer by dipping or the like can prevent contamination of the surface of the molded product and reduce the number of molding cycles. As the amount increases, the release agent is lost from the mold surface and the release effect decreases, resulting in problems such as the need to frequently apply the release agent.

[0006] Even when mixing a mold release agent into the resin to improve the releasability between the mold and the resin layer, if the compatibility between the resin and the mold release agent is not good, the mold release agent in the molded product may There was a problem with cloudy weather.

[0007] Therefore, the object of the present invention is to provide a mold release agent that is easy to manufacture because it has good mold releasability without the need to frequently apply a mold release agent;
Moreover, it is an object of the present invention to provide an optical element that is free from clouding and is not limited by product shape.

[0008]

[Means for Solving the Problems] According to the present invention, an organic phosphate ester or its salt, an organic An optical element is provided in which a resin layer is formed containing a total amount of phosphite ester and hydroxyalkylamine from 0.005 to 1.0% by weight based on the resin.

The urethane-modified (meth)acrylate in the ultraviolet curable resin of the present invention is a polyester oligomer obtained from a polyhydric alcohol and a polybasic acid. isocyanate groups are bonded to each other, and a (meth)acrylate having a hydroxyl group is bonded to the isocyanate group at the other end of the diisocyanate.

[0010] The (meth)acrylate is a polyester (meth)acrylate in which a carboxyl group of a monocarboxylic acid having a (meth)acrylic group is bonded to the hydroxyl group at the end of the main chain and side chain of the polyester oligomer; Examples include alkyl or aryl (meth)acrylates such as (meth)acrylate, methyl (meth)acrylate, and phenyl (meth)acrylate.

As the polymerization initiator, one type or a combination of two or more types selected from benzophenone derivatives, acetophenone derivatives, and oxime compounds, which generate radical species upon irradiation with ultraviolet rays, is used.

[0012] The organic phosphate ester or its salt in the mold release agent used in the present invention may also include 2-alkyl phosphates such as 2-ethylphenyl phosphate, and metal ions such as Ca, K, Na, and Mg. Examples include saturated or unsaturated alkyl polyol phosphate esters containing.

[0013] Examples of the organic phosphite include phosphorous acid mono- or diphenyl ester, phosphorous acid mono- or dialkyl ester, phosphorous acid mono- or dialkoxyalkyl ester, and 2-alkylphenyl phosphite.

Further, as the hydroxyalkylamine, N-hydroxyethyl-N,N-di(2-hydroxyethyl)amine, N-hydroxybutyl-N,N-di(
Examples include N-hydroxyalkyl-N,N-di(2-hydroxyalkyl or alkenyl)amines such as 2-hydroxypropenyl)amine.

[0015] The component composition in the resin includes optical properties, heat resistance,
Various composition ratios are possible depending on environmental resistance, processability, etc., but urethane-modified (meth)acrylate 10 to 90% by weight
The content of the photopolymerization initiator is preferably 25 to 70% by weight, the (meth)acrylate content is 5 to 80% by weight, preferably 20 to 70% by weight, and the photopolymerization initiator content is 0.5 to 10% by weight.

The component composition of the mold release agent is about 15 to 30% by weight of organic phosphoric acid ester (salt), preferably 20 to 28% by weight, and 10 to 70% by weight of organic phosphorous ester.
The amount is preferably 20 to 60% by weight, and the amount of hydroxyalkylamine is preferably 5 to 25% by weight, preferably 10 to 20%.
Weight%. It is also possible to add fatty acid alkyl esters, fatty acid mono- or dialkanolamides as other components.

[0017] The mixing ratio of the mold release agent to the ultraviolet curable resin is such that there is no bleeding, clouding, or peeling of the coating film (antireflection film, etc.) caused by the mold release agent, and it improves the releasability of the resin from the mold. 0.005~ to resin in order to
The content should be 1.0% by weight, preferably 0.0% by weight.
0.007 to 0.5% by weight.

[0018]

[Examples] The present invention will be specifically explained below with reference to Examples.

[Example 1] FIG. 1 is a schematic cross-sectional view showing a replica method for forming an aspherical resin layer on a glass surface. 1
is a mold holder, 2 is a mold, and 3 is a gasket.Resin is injected into the gap between the mold 2 and the glass lens, the resin is hardened by irradiating light from the lens side, and the resin is placed on the optical glass lens 5. Form layer 4.

40% by weight of polyurethane acrylate, 20% by weight of tris(2-acryloxy)isocyanurate
and 55% by weight of 2-ethylphenyl phosphite, based on the ultraviolet curable resin obtained by adding 2% by weight of hydroxyhexylphenyl ketone as a photopolymerization initiator to 40% by weight of dicyclopentyloxyethyl acrylate;
0.00% of a mold release agent having a composition of 25% by weight of calcium ethylene glycol phosphate, 10% by weight of phenyldioctyl phosphite, and 10% by weight of N-hydroxy-N,N-di(2-hydroxyoctyl)amine.
A mold (Starbucks manufactured by Udeholm) 2 in which a resin composition mixed with 5% by weight was mirror-finished into an aspherical concave shape with a diameter of 30 mm, a reference radius of curvature of 45 mm, and a maximum thickness deviation of 70 μm.
An optical glass lens (diameter 33 mm, radius of curvature R1
= 15.8 mm, R2 = 41.3 mm, and a convex lens (having an effective beam diameter of 30 mm) 5 was placed and fixed. Next, an ultra-high pressure mercury lamp of 40 W/cm was irradiated from the glass base material side for 10 minutes to form an aspherical resin layer 4 on one side (R1) of the glass base material.
A lens having the following properties was formed.

The releasability of the lens after molding was very good, with no resin remaining on the mold, and the mold surface maintained its state before molding. Molding was subsequently performed 500 times, but the lens surface maintained sufficient optical precision, and no resin adhered to the mold surface.

[0022] Furthermore, an antireflection film was deposited on the lens after molding, and an environmental test {70°C, 85%, 500 hours; -30°C
(1 hour) and 60°C, 60% (1 hour) for 20 cycles), evaluation tests were conducted on the optical properties of the lens, the adhesion, strength, and solvent resistance of the anti-reflection film. No abnormalities such as bleeding were observed, and the resin was equivalent to resin without a mold release agent mixed therein.

[0023] Furthermore, when a resin layer was molded under the same conditions using glass subjected to silane coupling treatment and the above-mentioned mold material, and the adhesive breaking force between the resin layer and the Starbac mold was measured according to JIS K6849, it was found to be 6. .7kgf/c
It was m2.

[Comparative Example 1] Mixing amount of mold release agent was 0.004
When molding was carried out under the same conditions as in Example 1 except for the weight %, resin remained on the mold surface during the third molding.

[0025] Furthermore, a resin layer was formed in the same manner as in Example 1, and the adhesive breaking force between the resin layer and the mold was measured according to JIS K6849, and it was found to be 19.2 kgf/cm2.
Met.

[Comparative Example 2] Molding was carried out under the same conditions as in Example 1, except that the mixing amount of the mold release agent was 1.5% by weight. During molding, the resin layer peeled off from the mold. The optical surface precision of the molded product deteriorated significantly.

[Comparative Example 3] Molding was carried out under the same conditions as in Example 1, except that the amount of mold release agent mixed was 1.05% by weight. The mold release property of the lens after molding was good, and no resin residue was observed on the mold surface.However, when an antireflection film was deposited and an environmental test was conducted under the same conditions as in Example 1, minute spots were found on the lens surface. There has occurred. When these spots were observed under a microscope, they were found to be due to peeling between the resin layer and the antireflection film.

[Example 2] Urethane-modified acrylate 5
0% by weight, 20% by weight of 2-hexyl phenyl phosphite, 40% by weight of 2-hexyl phenyl phosphite, 20% by weight of diphenyldodecoxyethyl phosphite, 20% by weight of magnesium butenediol phosphate, N-hydroxy-N and N-
A resin composition containing 1.0% by weight of a mold release agent having a composition of 20% by weight of di(hydroxyhexadecyl)amine,
Molding was carried out using the same mold as in Example 1 under the same conditions to form a lens having an aspherical resin layer.

The mold release property of the lens after molding was very good, with no resin remaining on the mold, and the mold surface maintained its state before molding. Molding was subsequently performed 500 times, but the lens surface maintained sufficient optical precision, and no resin adhered to the mold surface.

Furthermore, an antireflection film was deposited on the molded lens, and an environmental test was conducted under the same conditions as in Example 1. Even after the test, evaluation tests were conducted on the optical properties of the lens, the adhesion, strength, and solvent resistance of the anti-reflection film, and the results were the same as those of the resin without a release agent, and no bleeding or peeling was observed. There wasn't.

[0031] Furthermore, the adhesive breaking force between the resin layer and the mold was measured according to JIS K6849 under the same conditions as in Example 1, except that the resin was different, and it was found to be 3.1 kgf/cm2.
Met.

[Example 3] FIG. 2 is a schematic cross-sectional view showing a replica method for forming a resin layer having an uneven shape on the surface of a glass plate. A quartz glass substrate with excellent flatness accuracy is fabricated by photolithography with a pitch length of 1.6 μm and a groove depth of 0.13 μm.
, on a mold 10 processed into an uneven shape, 1% by weight of benzyl dimethyl ketal as a photopolymerization initiator was added to 50% by weight of urethane-modified acrylate, 20% by weight of trimethylolpropane trimethacrylate, and 30% by weight of benzyl acrylate. 0.01 of a mold release agent having the same composition as that used in Example 1 was added to the obtained ultraviolet curable resin.
A thoroughly cleaned quartz glass plate 1 with a flatness accuracy of 5 newtons or less is placed on top of the resin composition mixed in weight%.
3 was placed thereon, and the resin was cured by irradiating it from above with an ultra-high pressure mercury lamp of 40 W/cm for 2 minutes. 11 is a spacer.

The diffraction grating made of the resin layer 12 after molding is as follows:
Pitch length 1.6±0.05μm, groove depth 0.13±0.
It had an excellent molding accuracy of 0.02 μm.

Next, as a reflective film, Cu was coated with a thickness of 0.15 μm.
After forming a 0.2 μm thick film of SiO2 as a protective layer, an environmental test was conducted under the same conditions as in Example 1.

The evaluation results were the same as for the resin not mixed with a mold release agent, and it was possible to use it as an optical precision scaler.

[Comparative Example 4] When the same ultraviolet curable resin as in Example 1 was used except that the mold release agent was 0.05% by weight of polydimethylsiloxane, the same ultraviolet curable resin as in Example 1 was mixed. This resulted in clouding (white turbidity), making it unsuitable for optical applications.

[0037]

As described above, according to the present invention, organic phosphate ester or its salt, organic An optical element formed with a resin layer containing a total amount of 0.005 to 1.0% by weight of phosphite and hydroxyalkylamine based on the resin can prevent resin clouding, bleeding, and coating caused by a mold release agent. without causing peeling of membranes, etc.
Further, the molded product can be easily released from the mold without performing mold release treatment on the mold.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a state when a resin layer is formed on a lens.

FIG. 2 is a schematic cross-sectional view showing a state in which an uneven resin layer is formed on the surface of a glass plate.

[Explanation of sign]

1 Type holder 2 Molding mold 3 Gasket 4 Resin layer 5 Optical glass lens 10 Molding mold 11 Spacer 12 Resin layer 13 Quartz glass plate

Claims (1)

[Claims] Claim 1: A UV-curable resin containing urethane-modified (meth)acrylate and (meth)acrylate as monomer components, an organic phosphate ester or its salt, an organic phosphite ester, and a hydroxyalkylamine on a glass base material. The total amount is 0.005 to 1.0 to the resin.
An optical element on which a resin layer containing % by weight is formed.