JPH0370715A - Optical resin excellent in impact resistance - Google Patents

Abstract

PURPOSE:To obtain the subject resin, excellent in transparency with high refractive index by blending a methacrylic acid ester with a polyfunctional methacrylate and diacrylic acid diester, further blending the resultant monomer composition with a peroxy ester as a curing agent and hot-curing the prepared blend. CONSTITUTION:The objective resin obtained by blending a monomer composition composed of 1-30wt.% methacrylic acid ester (e.g. methyl methacrylate) expressed by formula I (R1 is 1-4C alkyl or alkenyl) with 5-40wt.% polyfunctional methacrylate (e.g. trimethylolpropane trimethacrylate) having 3-6 methacryloyl groups and 30-90wt.% diacrylic acid diester [e.g. 2,2-bis(acryloxydiethoxyphenyl)propane] expressed by formula II (R1 is H or methyl; (m+n) is 4-20) with a peroxy ester (e.g. tertbutyl peroxyacetate) as a curing agent in an amount of 0.5-5wt.% based on the monomer composition and hot curing the prepared blend.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an optical resin having excellent impact resistance and transparency and a high refractive index.

<Prior Art> In recent years, the use of resins has been expanding more and more in the optical field. This is because the resin has better impact resistance, lightness, moldability, dyeability, etc. than inorganic glass.

As optical resins, for example, polymethyl methacrylate, polydiethylene glycol bisallyl carbonate, polystyrene, polycarbonate, etc. are already known. However, although polymethyl methacrylate and polydiethylene glycol bisallyl carbonate have excellent impact resistance, light weight, and moldability, when used as plastic lenses, they have a low refractive index of around 1.49, and are therefore more expensive than inorganic glass. However, this method also has the disadvantage that it is necessary to increase the thickness of the lens, making it unsuitable for compact design.

Further, the polystyrene and polycarbonate have a refractive index of 1
．． Because it is thermoplastic with a high value of 58 to 1.59,
It has the disadvantage of easily causing optical distortion due to birefringence during injection molding, and furthermore, it has a low Abbé number.

Defects occur in solvent resistance and scratch resistance.

In order to improve the above drawbacks, for example, JP-A-53-77
No. 87 discloses an example of a copolymer of diethylene glycol bisallyl carbonate and diallyl isophthalate, and JP-A-59-191708 discloses a copolymer of di(meth)acrylate containing bisphenol A, diallyl isophthalate, and diethylene glycol bisallyl Examples of copolymers with carbonate, etc. have been proposed, but due to differences in copolymerizability, these have drawbacks such as unreacted allyl monomers tend to remain, making the polymerization process difficult, and poor weather resistance. There is.

Furthermore, JP-A-57-28115 discloses a copolymer of a styrene derivative and an unsaturated carboxylic acid heavy metal salt, and JP-A-60-55007 discloses a copolymer of a nuclear halogen-substituted diallyl phthalate and a nuclear halogen-substituted allyl benzoate. copolymers have been proposed, but these have a refractive index of 1.58 to
Although it has a high value of 1.60, it has the disadvantage that it contains a lot of heavy metal ions and halogen atoms, so it has a high specific gravity and makes the lens heavy.

Furthermore, in JP-A-55-13747, a copolymer of a di(meth)acrylate monomer having nuclear halogen-substituted styrene and bisphenol A, and a phenyl methacrylate monomer is disclosed in JP-A-59-133211.
The publication proposes a copolymer of hydroxyl (meth)acrylate having an aromatic ring, a diisocyanate monomer, and a styrene monomer, but these also have a high refractive index of around 1.60, but have poor weather resistance. Low.

It has disadvantages such as high specific gravity.

<Problems to be Solved by the Invention> An object of the present invention is to provide a material having transparency and a relatively high refractive index,
Another object of the present invention is to provide an optical resin that has excellent physical properties such as impact resistance, heat resistance, solvent resistance, and weather resistance, and has a low specific gravity and excellent impact resistance.

<Means for Solving the Problems> According to the present invention, methacrylic acid esters 1 to 1 represented by the following general formula (1) (wherein R□ represents an alkyl group or an alkenyl group having 1 to 4 carbon atoms)
30% by weight, 5 to 40% by weight of a polyfunctional methacrylate having 3 to 6 methacryloyl groups in one molecule, and a peroxyester as a curing agent to the monomer composition of general formula (n), by the total weight of the monomer composition. An optical resin having excellent impact resistance is provided by blending 5 to 5% by weight of Q to the total weight of the compound and heat-curing the resin.

The present invention will be explained in more detail below.

The optical resin of the present invention is a copolymer obtained by heating and curing a monomer composition containing a specific methacrylic acid ester, a polyfunctional methacrylate, and a specific diacrylic acid diester using a peroxyester as a curing agent.

The specific methacrylic acid ester used in the present invention can be represented by the following general formula (1), (wherein R1 represents a hydrogen atom or a methyl group.

m + n represents an integer of 4 to 20, in which R1 represents an alkyl group or alkenyl group having 1 to 4 carbon atoms;
In this case, if the number of carbon atoms in R1 is 5 or more, the heat resistance of the resin may decrease. Examples of the methacrylic ester represented by the general formula (1) include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-propyl methacrylate, isobutyl methacrylate, 5ec-butyl methacrylate, n-butyl methacrylate, allyl methacrylate, Examples include metaallyl methacrylate.

When used, they can be used alone or as a mixture.

The polyfunctional methacrylate used as a monomer composition component in the present invention is a monomer that has 3 to 6 methacryloyl groups in one molecule and particularly imparts heat resistance. Examples of the polyfunctional methacrylate include trimethylolpropane trimethacrylate, ditrimethylolpropane tetramethacrylate, pentaerythritol trimethacrylate, tris-(methacryloyloxyethyl)in cyanurate, dipentaerythritol hexamethacrylate, and the like. When used, they can be used alone or as a mixture.

In the present invention, the specific diacrylic acid diester used as a monomer composition component has the following general formula (II).
It can be expressed as In some cases, heat resistance decreases. Examples of the diacrylic acid diester represented by the general formula (n) include 2,2-bis(acryloxyjethoxyphenyl)propane, 2,2-bis(acryloxytriethoxyphenyl)propane, and 2,2-bis(acryloxytriethoxyphenyl)propane.
Bis(acryloxytetraethoxyphenyl)propane, 2,2-bis(acryloxypentaethoxyphenyl)propane, 2,2-bis(acryloxyhexaethoxyphenyl)propane, 2,2-bis(acryloxyhexaethoxyphenyl) Propane, 2,2-bis(acryloxyoctaethoxyphenyl)propane, 2,2-
bis(acryloxynonaethoxyphenyl)propane,
2,2-bis(acryloxydecaethoxyphenyl)propane, 2,2-bis(acryloxydipropoxyphenyl)propane, 2,2-bis(acryloxytripropoxyphenyl)propane, 2,2-bis(acryloxy Tetrapropoxyphenyl)propane, 2,2-bis(acryloxypentapropoxyphenyl)propane,
2,2-bis(acryloxyhexapropoxyphenyl)propane.

2゛, 2-bis(acryloxyhebutapropoxyphenyl)propane, 2,2-bis(acryloxyoctapropoxyphenyl)propane, 2,2-bis(acryloxynonapropoxyphenyl)propane, 2,2-bis(
Examples include acryloxydecapropoxyphenyl)propane.

To prepare the diacrylic acid diester represented by the general formula (rl), for example, bisphenol or propylene oxide is obtained in the presence of a basic catalyst (when ethylene oxide is used), and the resulting adduct is mixed with acrylic acid. It can be produced by a method such as reacting a methyl acid with a transesterification method. As the basic catalyst,
For example, alkali, alcoholade, etc. can be preferably mentioned. A specific example of the reaction using ethylene oxide can be expressed by the following reaction formula.

CH,=CHC00CH.

=CH,OH At this time, since the above reaction is a ring-opening addition reaction of ethylene oxide or propylene oxide, controlling the molecular weight of the diacrylic acid diester becomes more difficult as the PEG length becomes longer. Therefore, m+n in the above reaction formula needs to be in the range of 4 to 20.

In the present invention, the blending ratio of the three types of monomer components contained in the monomer composition is 1 to 30% by weight, preferably 5% by weight of the methacrylic acid ester represented by general formula (1).
~25 weight% weight functional methacrylate 5~40 weight%
, preferably 10 to 35% by weight, and 30 to 90% by weight, preferably 40 to 90% by weight of diacrylic acid diester represented by general formula (If). At this time, if the blending ratio of the methacrylic ester exceeds 40% by weight,
The shrinkage rate during curing increases significantly, and the refractive index and solvent resistance of the resin decrease. Furthermore, if the content of polyfunctional methacrylate exceeds 40% by weight, the impact resistance will be significantly reduced. Furthermore, if the diacrylic acid diester is less than 30% by weight, the impact resistance will be lowered, and if it exceeds 90% by weight, the heat resistance will be lowered, so that it cannot be used.

In the present invention, as a monomer composition component.

In addition to the above-mentioned monomers, other vinyl monomers may also be contained, preferably in an amount of 10% by weight or less based on the total weight of the monomer composition. Examples of the other vinyl monomers that can be used include styrene, nuclear-substituted methylstyrene, nuclear halogen-substituted styrene, divinylbenzene, vinyl acetate, vinyl benzoate, divinyl phthalate, divinyl isophthalate, divinyl terephthalate, cyclohexyl (meth)acrylate, Ethylene glycol di(
meth)acrylate, diethylene glycol di(meth)
Acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol bisallyl carbonate, vinyl(meth)acrylate, etc. can be mentioned, and they can be used alone or as a mixture.

In the present invention, as the peroxyester used as a curing agent when heating and curing the monomer composition, peroxyesters having a half-life temperature of 120°C or less, preferably 1±selected 10 hours, can be used. Examples include tert-butyl peroxy acetate, tert-butyl peroxy isobutyrate, tert-butyl peroxy pivalate, tert-butyl peroxy neodecanoate, tert-butyl peroxy-2-ethylhexanoate. , tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxy laurate, cumyl peroxy neodecanoate, cumyl peroxy octoate, tert-hexyl peroxy neodecanoate, Examples include tertiary hexyl peroxy pivalate, which can be used alone or as a mixture. The amount of the curing agent used is 0.5 to 5% by weight, preferably 1 to 4% by weight, based on the total weight of the monomer composition. If the amount of curing agent used is less than 0.5% by weight, curing will be insufficient and physical properties will deteriorate, and if it exceeds 5% by weight, curing will be difficult to control and surface cracks will easily occur. Therefore, it is necessary to use it in a range of 0.5 to 5% by weight.

Optical resin of the present invention! 1 can be obtained by, for example, adding the peroxyester as the curing agent to the monomer composition, directly charging it into a desired mold, and heating and curing it. The temperature during heating and curing varies depending on the curing agent used, but is 30 to 10
A range of 0°C is preferable, and a temperature around the 10-hour half-life of the curing agent used is more preferable, and it is also possible to raise the curing temperature at any time for the purpose of shortening the curing time and disposing of unreacted monomers and curing agents. be. In this case, the total time required for curing is preferably in the range of 10 to 48 hours. It is preferable that the heat curing is performed under an atmosphere of inert gas such as nitrogen, helium, or carbon dioxide. In addition, before heating and curing, a curing agent is added to the monomer composition, and after prepolymerizing at a predetermined temperature, preferably 30 to 70°C for 0.1 to 6 hours, it is placed in a mold and heated to harden. It is also possible to use methods that bring the polymerization to completion. Further, it is also possible to use a photopolymerization initiator, a photosensitizer, etc. in combination with the peroxyester used as the curing agent, and to prepare the composition by a combined thermo-photopolymerization system.

Specifically, for example, after performing the prepolymerization, curing is completed by photocuring with ultraviolet rays in the presence of a photopolymerization initiator, a photosensitizer, etc.; It is also possible to use a method in which a curing agent is added afterwards and the curing is completed by heating.

Furthermore, in the optical resin of the present invention, it is also possible to further add a colorant, an ultraviolet absorber, an antioxidant, etc., and then cure the resin, if necessary.

<Effects of the Invention> The optical resin of the present invention has excellent impact resistance, heat resistance, etc., has a refractive index of 1.55 or more, an Atsubbe's number of 40 or more, is colorless and transparent, and overcomes the drawbacks of conventional optical resins. Since it is an improved material, it can be applied to optical fields such as eyeglass lenses, camera lenses, optical elements, and high refractive index resin plates.

<Examples> The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto.

In addition, various physical properties were measured by the methods described below.

Dankyuo, Elle hope Atsube refraction measurement On a hardened plate of thickness 2I + 11, height 127cm - 4
A 5g steel ball was dropped, and those that did not break were rated 0, and those that did crack were rated x.

LiJi After being left in a dryer at 130° C. for 2 hours, those in which no changes such as deformation, cracking, or coloring were observed in the resin were rated 0, and those in which any changes were observed were rated ×.

Specific gravity: Determined by weight of resin/resin volume by underwater displacement method.

Ai Nezumi and Tsuji: After being left in acetone for 2 hours, no changes such as deformation, cracking, or coloration were observed in the resin, and those in which no changes were observed were rated O1.

Leaving J! LflL 0.2 g of tertiary-butyl peroxypivalate is added to a raw material monomer mixture consisting of 1 g of methyl methacrylate, 7 g of diacrylic acid diester J represented by the following general formula (a mixture of m+n=8 on average), and 2 g of trimethylolpropane trimethacrylate.
g was mixed, then placed in a mold sandwiched between two glass plates (using an ethylene acrylate gasket), and heated to 55°C.
The curing temperature was set at 55° C. and heated for 15 hours in a constant temperature bath, the temperature was further increased to 100° C. in 3 hours, and finally annealing treatment was performed at 100° C. for 2 hours. After completion, the cured resin was taken out from the mold and evaluated by the physical property test described above. The results are shown in Table 1.

Raw material monomers were obtained in the same manner as in the example process, except that the monomers shown in Table 1 were used, and a cured resin was prepared using the curing agent and curing conditions shown in the front process, and physical property tests were conducted. . The results are shown in Table 1.

A cured resin was prepared in the same manner as in Example 1, except that the monomers shown in Table 2 were used, and physical property tests were conducted. The results are shown in Table 2.

However, * and the curing agent in the table are as follows.

*I MMA Methyl methacrylate 1g BP
A (m+n) *3 *4 MPT EGBA Trimethylolpropane trimethafrylate diethylene glycol bisallyl carbonate PP Diisopropyl peroxydicarbonate wood 5 PM BPP BPE BPI BPN CP.

P.O. Tert-butyl peroxypivale root tert-butylperoxy-2- Ethylhexanoate Tarjaly Butyl Peroxyisobu Chilate tert-butylbaroxy-2- Ethylhexanoate Cumyl baroxyoctoate Pennzoyl peroxide

Claims (1)

[Claims] Represented by the following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the formula, R_1 represents an alkyl group or an alkenyl group having 1 to 4 carbon atoms.) Methacrylic acid ester 1
-30% by weight, 5-40% by weight of polyfunctional methacrylate having 3-6 methacryloyl groups in one molecule, and general formula (II) ▲Mathematical formulas, chemical formulas, tables, etc.▼...(II) ( In the formula, R_1 represents a hydrogen atom or a methyl group, and m+
n represents an integer of 4 to 20. ) to a monomer composition containing 30 to 90% by weight of diester diacrylate, 0.5 to 5% by weight of peroxyester as a curing agent based on the total weight of the monomer composition, and heat-cured. Optical resin with excellent impact resistance.