JPS58162617A - Optical resin composition and optical element - Google Patents

Abstract

PURPOSE:An optical resin composition that contains a specific N-vinylcarbazole of high melt index as the major component, thus showing improved optical birefringence in injection and compression molding. CONSTITUTION:The objective composition contains 95-100wt% of a polymer containing more than 50wt% of N-vinylcarbazole as the major monomer component such as N-vinyl carbazole-styrene copolymer, N-vinylcarbazole-t-butylstyrene copolymer and shows a melt index of higher than 3.0g/10mit in accordance with ISOR-1133 testing at 275 deg.C, 5kgf and a glass transition point of over 120 deg.C. The resultant composition is subjected to injection or compression molding to make lenses for steal cameras or video cameras, prisms such as pentaprisms and other optical elements.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plastic optical element made by injection molding, compression layering, etc., and a resin composite containing N-vinylcarbazole as a main component used therein.

Plastic optical elements have advantages such as being lighter than glass ones, having high impact resistance, no polishing required, easy mass production, and the ability to mass produce aspherical lenses, so they have become popular in recent years. Demand is increasing. However, compared to glass-based optical elements, plastic optical elements have lower precision due to manufacturing aspects or characteristics of the plastic material itself, and also have a smaller range of refractive index selection and greater birefringence. However, these drawbacks have been factors that have hindered the use of plastic optical elements.

Birefringence of optical elements is a major problem in precision optical systems that are sometimes used to read and write information using light such as lasers, and the development of plastic optical elements with even lower birefringence has been desired. As is well known, the birefringence of plastic optical elements changes depending on the properties of the material itself as well as the molding conditions. Therefore, until now, reduction of birefringence of plastic optical elements has usually relied on IE type conditions. However, as the demand for more precise optical elements increases,
At Tohoku, it became necessary to overcome the unavoidable birefringence by changing the material itself.

Therefore, an object of the present invention is to provide an optical plastic material rt11I which is further improved in injection molding, compression molding, etc. and exhibits tII refractive properties.

Another object of the present invention is to provide a plastic optical element exhibiting improved birefringence, which is made by using N-vinylcarbazole as a main component. The melt index value of a polymer whose main component is a monomer component is II! OR-1133g test method, 275℃,
5 to 9f f) Condition 't' 3.011/10 minutes or more, an optical resin having a glass transition temperature of 120°C or higher, and an optical resin composition obtained by forming an optical resin composition. This is achieved by the element.

Here, a polymer containing N-vinylcarbazole as the main monomer component means that the N-vinylcarbazole component in the polymer has a high sO weight. Approximately 95 weight arc to 100
It means that the weight ratio is the polymer.

The present invention uses a resin composition whose main component is a polymer whose main monomer component is N-vinylcarbazole, which has a sufficiently larger melt index value than conventional general-purpose lid-forming resins.

In molding optical elements, resin is melted and cooled in a metal lid to obtain a molded product, but the resin on the left, which has high viscosity when melted, is cooled unevenly, causing optical distortion in AM products. The remainder appears as birefringence. Especially in the case of injection molding,
Since the resin 11f is injected into the metal lid, the orientation of the resin remains in the direction of flow in a highly viscous state, which tends to cause birefringence.

The viscosity of molten resin depends on the temperature of the resin, as shown in the 1st WJ, so if it is melted at a relatively high temperature, a low viscosity can be obtained, but there are factors such as decomposition of the resin. It cannot be raised.

The inventors of the present invention discovered that the birefringence of the resin T&lid product quantitatively correlates with the melt e index value of the resin, as shown in Figure 2, and as a result of further intensive research, N-vinylcarbazole ! In a resin composition whose main component is a polymer of a 7-mer composition containing more than 50% by weight, the melt index value is 180% by weight according to the I80 B-1133 test method,
If it is 3.0 jl/10 minutes or more under the conditions (275°C, 519ff), the birefringence may sometimes be changed compared to N-vinylcarbazole resins or resin compositions conventionally used for optical elements. I found it.

A substance containing more than 50% N-vinylcarbazole used in the present invention! - In order to increase the melt index value of the polymer in the composition, it is appropriate to make the molecular weight smaller than the commonly used molecular weight, but if the molecular weight is too small, the heat resistance of the finished product will be Sex is evil (
Therefore, the TI of the resin composition must be kept at 120°C or higher.

In the resin 11Wa product according to the present invention, in order to increase the melt index value, residual monomers during polymerization of the polymer required in the present invention are used. -Relatively many things within the range that controls and does not affect @Rinaki at the time of removal! - The preferred amount of residual monomer is 1#ll.
2 weight or less, more preferably o, s for 11 samples
Less than arrogant.

The resin composition according to the present invention may contain a binder to increase the melt fist index value. Examples of the malleable agent include lua #i in alcohol such as 2-ethylhexyl 7#re), tome-butyl 7#late, isodecanyl 7thalate, tridecanyl phthalate, heptyl 7#late, nonyl 7#re), -), alkyl esters of dibasic acids such as fi-ethylhexyl adipate and 2-ethylhexyl sepacate, phosphoric acids such as tributyl phosphorus, triotacyl phosphate, tricresyl phosphate, and trisulfate triphosphate. esters, dimexylated butyl oleate, engineered butylene oleate A'Q14F)! m
Any compound having the function of a softening agent, such as oxygenated fatty acid ester-1, chlorinated fatty acid ester, etc., can be used. Furthermore, two or more of these may be used in combination.

When the resin composition of the present invention contains a monomer other than N-vinylcarbazole, any monomer that remains transparent after polymerization may be included;
In particular, styrene, chlorstyrene, p-mostyrene, sodium carbonate
Halogenated styrenes that have ** halogen substituents on dostyrene and pentene, alkylstyrenes that have a pulky substituent such as tertiary butyl styrene and tertiary butyl styrene, and halogenated styrenes that have ** halogen substituents on the benzene nucleus; Alkyloxystyrenes having one or more fulkyloxy groups, such as alkylthiostyrenes having one or more alkylthio groups such as phenylthio or mercapto groups in the benzene nucleus, cyclohexyl methacrylate, -adamantyl methacrylate, 2-methylcyclohexyl methacrylate , isoboronyl methacrylate, glycidyl methacrylate-Fl and Japanese Patent Publication No. 51-2
A series of acrylic acid-based products used in polymer synthesis described in Japanese Patent No. 519. - Acrylic acid or methacrylic acid ester region containing Ill, halogen atom t in benzene nucleus
The combination of methacrylic acid with polyhydric alcohols such as 7-El methacrylates with one or more nuclear substitutions, conjugated disilyls such as acrylate ethyl, methacryl nitrile, ethylene glycol, diethylene glycol, pentaerystol, and rimethyl nitrile propane. Preferred are alkyl allyl ethers such as ester esters and allyl diglycol carponesi.

Specific examples of polymers used in the present invention include 1N-vinylcarbazole, styrene (814) copolymer, N-vinylcarbazole, tert-butylstyrene<614
5 copolymer, N-vinylcarbazole, methyl metatarylate (81 copolymer, x-vinylcarbazole,
Examples include 12% styrene (8g2) copolymer, N-vinylcarbazole, and tristyrene (1$t4) copolymer.

The polymerization method of the polymer used in the present invention is not limited in some cases, and includes, for example, suspension polymerization, solution polymerization, bulk polymerization,
Radiation Gijukai etc. are used.

The resin composition of the present invention may contain an ultraviolet absorber to improve light resistance.As the ultraviolet absorber, it is not preferable to use one that reduces the transmittance in the visible region. Any substance can be used as long as it effectively absorbs ultraviolet AT without impairing the properties of UV rays. Specific examples include 1, ortho-human tetraxysalicyl lI phenyl compounds, ortho-human gastric dipenzophenone compounds, and 2-(0-hytronexyl). Benzotriazole compounds, cyanoacrylate compounds, etc. can be used.

The $11 method for producing optical element tubes by molding the resin composition of the present invention includes injection molding, compression molding, the lowlinks method which is a compromise between injection molding and compression molding, and micromolding. After melting or semi-melting approximately one carrier resin, #14I! Any method can be applied. Among these @lid methods, the effect of the present invention is greatest in the molding method in which the degree of birefringence produced by molding is relatively large; The low links method! It is advantageous in the itagastric molding method, and the compression S
It is also advantageous in the at method.

True fluidity resin 1111 is disadvantageous from the viewpoint of heat resistance, so in the present invention, a crosslinkable resin is added to the resin composition before assembly! 1 with increased fluidity by containing a small amount of
For example, r-rays, electron beams/X@, ultraviolet rays, etc.
A method of cross-linking and curing by applying a layer of lI tube may also be used.

In addition, moisture absorption of the molded product can have a large effect on the thermal stability of the molded product, so in order to improve the dimensional stability of the molded product, it is important to place resin footings on the surface of the molded product. Therefore, measures may be taken to prevent moisture absorption and improve dimensional stability as a result. Top resin coating methods include, for example, monomer or pre-coating methods. -tlki
1, followed by a method of polymerizing and curing by thermal polymerization, injection polymerization, electronic polymerization, etc., a method of spraying a primer III solution, a method using a plus i polymerization, etc. surface coat
Examples of resins for coating include fluoroalkylenes (abbreviation for tetra7tethylene), organosilanes such as tetramethylsilane, orthosilicates such as tetraethyl orthosilicate, fluoroalkyl methacrylates such as pentafluorotetraethyl methacrylate, and acrylonitrile. Examples thereof include conjugated nitriles, styrene, and polymers containing styrenes such as polystyrene as a monomer component.

The polymer of the present invention is suitable for molding a good optical element with low birefringence compared to the case where a general molding N-vinylcarbazole resin is used, but it is more preferable that the polymer has a melt index value. ISOR-1133 law,
275°C, 5kjf condition r 5. It is desirable that the ON time is at least 10 minutes, more preferably at least 10 l/10 minutes.

Optical elements obtained by molding the resin composition of the present invention include, for example, baths, steel cameras, video cameras, telescopes, eyeglasses, contact lenses, sunlight condensing devices, etc. By transmitting or reflecting light, so-called lenses, prisms such as pentaprisms, mirror mirrors such as concave mirrors and polygons, guiding elements such as optical fibers and optical waveguides, discs such as video discs and audio discs, etc. The present invention will be explained in more detail by giving examples below.
The present invention is not limited thereby.

Example 1 1% calcium phosphate, 0.01 part of sodium dodecylbenzenesulfonate, and distilled water (mt) were injected into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a stirring rod, and a temperature needle. The following composition was added and reacted at 70°C for 6 hours.

(11m product) After the polymerization reaction was completed, the product was treated with hydrochloric acid, washed with water, filtered, and dried to obtain a copolymer resin composition. The weight average molecular weight of this resin composition was 81. Goo, the glass transition temperature is 1
The temperature was 42°C, and the melt index value was I80 B-.
1133 test method, 275°C, 5kff conditions, 6.5
It was Ii/10 minutes.

When this resin composition was injection molded at a resin temperature of 280° to produce a lens molded product having a thickness of 3 cm at the center, the phase delay at the center was 310 degrees.

On the other hand, under the same conditions as above, the melt index value is z
, zlto was injection molded to create a lens molded product, and a molded product with a phase delay of 520 degrees was obtained.

Example 2 N-vinylcarbazole 5kII, methyl methacrylate 2kII, lauroyl peroxide 0. ! When the monomer mixture consisting of Y was subjected to a polymerization reaction in the same manner as in Example 1, a molded product having a weight average molecular weight of 142,000, a glass transition temperature of 152°C, and a melt index value of $880° was obtained.

[Brief explanation of the drawing]

giml is l1li! Figure 7 shows the relationship between temperature and Mel F index value. 1! An example of the resin composition of the present invention. &3 and 4! Melt index value is IgOR-1
133 test method, 275°C, 5kIIff) Conditions r3. l
N-vinylcarbazole e major i no / smaller than 10 minutes! - An example of a tree as a component. The second WJ is a graph showing the relationship between the melt index value and the *g fold of a one-liner product, and the lid temperature of the molded product is 280°C. ! ! The IK existing lvinylcarpasol mar or Hiromerci index value is l11031-1133 test method, 275°C, IIk#fe conditions 3.01710 min. What about the resin composition? Agent Yoshimi Kuwahara 11! I SO's Jv rebellion (°G) $2 figure J reto 1 Intellix so t◆length (currently 10.1)

Claims (2)

[Claims] (1) N-vinylcarbazole main bone! - The Φ index value is 3.1/10 minutes or more under the I80 B-1133 test method and the conditions of 2'1SC1Sklf, and the glass transition temperature is 1
Optical resin am product that has a temperature of 20°C or higher. (2) Merci index value force 1110 B-1133 test method, 275°C, for polymers whose main monomer content is N-vinylcarbazole. $kjf
An optical element obtained by processing a resin composition under the conditions of 3.0 #/10 minutes or more and a glass transition temperature of 120° C. or more.