JP2792259B2 - Manufacturing method of thermoplastic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a thermoplastic resin,
The present invention relates to a thermoplastic resin and a lens using the resin.

[0002]

2. Description of the Related Art Generally, diethylene glycol bisallyl carbonate resin (CR-39) which is a thermosetting resin is used as a resin for eyeglass lenses. When plastic is used for the spectacle lens, the weight is reduced as compared with glass, but the refractive index of CR-39 is 1.
However, there is a problem that the edge of the lens must be thicker than a glass lens (particularly, it becomes remarkable as the lens power increases).

For this reason, high-refractive-index resin for spectacle lenses capable of making the spectacle lens thinner and lighter is being developed (JP-A-57-54901 and JP-A-61-28).
7913, JP-A-58-153901, etc.).

[0004] These high-refractive-index resin for spectacle lenses are all thermosetting resins, and a casting polymerization method is applied as a method of manufacturing a lens using the thermosetting resin. There was a problem that sex was very bad.

[0005] On the other hand, thermoplastic resins to which an injection molding method excellent in productivity can be applied include polymethyl methacrylate (refractive index: 1.49, Abbe number: 58), polystyrene (refractive index: 1.58, Abbe number: 30), There is polycarbonate (refractive index 1.59, Abbe number 30). Polymethyl methacrylate is a resin having excellent transparency, but has a problem of a low refractive index. Polystyrene and polycarbonate have a high refractive index, but have a problem that chromatic aberration is large due to a small Abbe number, and the former has a low heat-resistant temperature, and the latter has a low surface hardness and is easily damaged.

[0006] Methyl methacrylate-styrene resin, tricyclo [5,
2,1,0 ² ' ⁶ ] dec-8-yl methacrylate-styrene resin (Japanese Patent Application Laid-Open No. 62-246001), but when the reaction is carried out at a conversion of 100% by a suspension polymerization method, refraction occurs in the latter half of the polymerization. Since components having different ratios are generated, the haze value increases, and the transparency decreases. In addition, the former has a problem that the heat-resistant temperature is low.

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and provides a method for producing an injection-moldable thermoplastic resin having low haze, high transparency and excellent heat resistance. And a lens using the resin.

[0008]

According to the present invention, tricyclo [5,2,1,0 ^2,6 ] dec-8-yl methacrylate is 10 to 40 parts by weight, styrene is 40 to 60 parts by weight, and methyl methacrylate is 10 to 40 parts by weight. Parts by weight, and a total of 100 parts by weight, and initiators a and t (1) having t (1/2) of 55 to 69 ° C.
/ 2) is 70 to 85 ° C and the initiators b and t (1/2) are 8
The present invention relates to a method for producing a thermoplastic resin, which comprises polymerizing in the presence of an initiator c at 6 to 170 ° C.

Hereinafter, the present invention will be described in detail. The used amount of tricyclo [5,2,1,0 ² ' ⁶ ] dec-8-yl methacrylate is 10 to 40 parts by weight, preferably 15 to 25 parts by weight. If the amount is less than 10 parts by weight, the heat-resistant temperature becomes low. If the amount exceeds 40 parts by weight, tricyclo [5,
[2,1,0 ² ' ⁶ ] dec-8-yl methacrylate is not preferred because the amount of unreacted monomer increases rapidly.

The amount of styrene used is 40 to 60 parts by weight, preferably 45 to 55 parts by weight. If it is less than 40 parts by weight, the refractive index becomes small, and if it exceeds 60 parts by weight, the Abbe number becomes small, which is inconvenient.

The amount of methyl methacrylate used is 10 to 4
0 parts by weight, and preferably 25 to 35 parts by weight. If the amount is less than 10 parts by weight, there is no effect on improving transparency, and the haze value increases. If the amount exceeds 40 parts by weight, the refractive index of the polymer decreases.

In addition, as long as the effects of the present invention are not impaired,
A monomer other than the above three monomers may be used.

These monomers have an initiator a having a decomposition temperature t (1/2) of 55 to 69 ° C., which has a half-life of 10 hours,
an initiator b having t (1/2) of 70 to 85 ° C., and t (1/2)
2) is polymerized in the presence of initiator c at 86-170 ° C, preferably 86-100 ° C.

The initiators must be used in combination of three types a, b and c. If only one or two types are used,
Even if the resin is in the above-mentioned monomer ratio range, the haze value increases and the desired resin cannot be obtained.

The total amount of the initiators a, b and c is preferably used in the range of 0.1 to 2.0% by weight of the total monomer.

(Initiator b + Initiator c) / Initiator a
(Weight ratio) is preferably 0.5 or more. If it is less than 0.5, the haze value of the resin tends to increase and the transparency tends to decrease.

Examples of the initiator a include t-butyl peroxypivalate, 3,3,5-trimethylhexanoyl peroxide, octanoyl peroxide, decanoyl peroxide, lauryl peroxide, cumyl peroxy octoate And succinic acid peroxide, acetyl peroxide and the like. Lauryl peroxide is preferred in view of the properties of the obtained resin.

Examples of the initiator b include t-butylperoxy (2-ethylhexanoate), m-toluoyl peroxide, benzoyl peroxide, t-
Butyl peroxyisobutyrate and the like. T-butyl peroxy (2-ethyl hexanoate) is preferred from the viewpoint of the properties of the obtained resin.

Examples of the initiator c include 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane and t-butylperoxy. Oxylaurate, t-
Butylperoxy, 3,3,5-trimethylhexanoate, t-butylperoxyaryl carbonate, t
-Butyl peroxyisopropyl carbonate, 2.5
-Dimethyl-2,5-di (benzoylperoxy) hexane, 2,2-bis (t-butylperoxy) octane, t-butylperoxyacetate, 2,2-bis (t-butylperoxy) butane , T-butylperoxybenzoate, n-butyl-4,4-bis (t-butylphenoxy) valate, di-t-butyl-diperoxyisophthalate, methyl ethyl ketone peroxide, di-cumyl peroxide, 2,5 -Dimethyl-
2,5-di (t-butylperoxy) hexane, α,
α'-bis (t-butylperoxy-m-isopropyl) benzene, t-butylcumyl peroxide, di-
Isopropylbenzene hydroperoxide, di-t-
Butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,1,1,3-tetramethylbutyl hydroperoxide, 2,5- Examples include dimethylhexane-2,5 dihydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide and the like. Among the initiators c, t (1/2) is 86
Those having a temperature of -100 ° C are preferred. 1,1-bis (t-butylperoxy) 3,3,3
5-trimethylcyclohexane and 1,1-bis (t-
Butylperoxy) cyclohexane is preferred, of which the former is particularly preferred.

In the polymerization system, a chain transfer agent, for example, a mercaptan compound, thioglycol, carbon tetrachloride, α-methylstyrene dimer and the like can be present.

The polymerization temperature until the conversion reaches 95% or more is preferably 70 to 90 ° C., and 75 to 85 ° C.
Is more preferable. If it is lower than 70 ° C., the polymerization time tends to be long, the haze value tends to be high, and the transparency tends to decrease. If it exceeds 90 ° C., the haze value tends to be high and the transparency tends to decrease.

For the polymerization, a known polymerization method may be applied, but a suspension polymerization method is preferred.

In the suspension polymerization method, polymerization is generally carried out in an aqueous medium using a suspending agent. Examples of the suspending agent include polyvinyl alcohol, methyl cellulose, polyacrylamide, poly (meth) acrylate and the like. Water-soluble polymer,
Insoluble inorganic substances such as calcium phosphate and magnesium pyrophosphate can be used.

In order to obtain a highly transparent resin, it is preferable to use poly (meth) acrylate as a suspending agent.
The suspending agent is used in an amount of 0.03-1.
It is preferred to use 0% by weight. If it is less than 0.03% by weight, the resin tends to solidify during polymerization. 1.0% by weight
When the amount exceeds the above range, the resin tends to be colored or lose transparency.

The poly (meth) acrylate which is a water-soluble polymer is a salt of (meth) acrylic acid (lithium salt, sodium salt, potassium salt, magnesium salt, calcium salt,
Ammonium salt) and a hydroxyalkyl (meth) acrylate, (meth) acrylic acid, or another copolymerizable unsaturated monomer.

The molecular weight of the thermoplastic resin of the present invention is not particularly limited, but heat resistance, mechanical properties,
From the viewpoint of moldability, the weight average molecular weight (in terms of polystyrene) is preferably in the range of 10,000 to 1,000,000.

The thermoplastic resin of the present invention has a refractive index of 1.54 or more, an Abbe number of 35 or more, and a glass transition temperature of 1 or more.
Those having a temperature of at least 00 ° C. and a haze value of at most 1.0% are preferred.

The thermoplastic resin of the present invention may be used in antioxidants such as phenolic, osphite, thioether and the like from the viewpoints of prevention of oxidative deterioration, thermal stability, moldability, processability, etc. Release agents such as fatty acid esters, phthalic acid esters, triglycerides, fluorine surfactants, higher fatty acid metal salts, lubricants, plasticizers, antistatic agents, ultraviolet absorbers, heat-resistant agents, heavy metal deactivators, etc. May be added for use.

The thermoplastic resin of the present invention can be injection-molded and is suitable for use in lenses such as eyeglasses.

[0030]

The present invention will be described below in detail with reference to examples. <Suspension: water-soluble polymer (A). Synthesis of (Polymethacrylate) 90 g of 2-hydroxyethyl methacrylate, 60 g of potassium methacrylate, and 2250 g of deionized water in an inner volume of 5 l
300ml / m for 30 minutes
N ₂ gas was blown in at a flow rate of “in” and the amount of oxygen in the water was 1 m.
After removing the air in the system until it becomes 1 / l or less, the system is stirred while heating in a water bath, and the temperature in the system is raised to 65 ° C while increasing the temperature at 0.7 ° C / min. Immediately, 0.225 g of potassium persulfate dissolved in 150 g of pure water was added. Polymerization was carried out at the same temperature for 3 hours, followed by 0.9 ° C / mi.
The temperature was raised to 90 ° C. while the temperature was raised with n, and stirring was continued at the same temperature for 2 hours to obtain a jelly-like water-soluble polymer (A). The viscosity of this water-soluble polymer is 40 cps (25 ° C.) and the light transmittance is 86%.
(400 nm wavelength).

Example 1 280 g of tricyclo [5,2,1,0 ² ' ⁶ ] dec-8-yl methacrylate (TCDMA), 700 styrene
g, methyl methacrylate (MMA) 420 g, Parloyl L (manufactured by NOF CORPORATION; lauryl peroxide)
5.6 g, perbutyl O (manufactured by NOF Corporation; t-butyl peroxy-2-ethylhexanoate) 2.8 g,
Perhexa 3M (manufactured by NOF Corporation; 1,1-bis (t
(Butyl peroxy) 3,3,5-trimethylcyclohexane) was mixed and dissolved to obtain a monomer solution.

To a 5 l separable flask equipped with a stirrer and a condenser, 0.7 g of the above-mentioned jelly-like water-soluble polymer and 1960 g of deionized water were added as suspending agents, and N ₂ gas was flowed at a flow rate of 300 ml / min. While continuing, the oxygen content in the flask space was reduced to 0.1% or less. The above composition was added thereto with stirring, and the temperature was raised to 80 ° C. at a rate of 0.7 ° C./min in a nitrogen atmosphere at a stirring rotation speed of 280 rpm, and the polymerization rate was 95% or more at this temperature for 4 hours at a specific gravity. After confirming that the temperature is
C., and polymerized at this temperature for 2 hours and then at 98.degree. C. for 2 hours. The synthesized polymer particles were washed with water until the attached amount of potassium became 1 ppm or less, dehydrated, and dried at 90 ° C. for 8 hours.

Next, the polymer particles were molded using an injection molding machine (Toshiba Machine Co., Ltd., IS-50EP) in which the mold temperature was set at 90 ° C. and the cylinder temperature was set at 240 ° C. The ratio, haze, refractive index, Abbe number, glass transition temperature (a measure of heat resistance), and the like were examined.

The characteristics were evaluated according to the following methods. -Light transmittance: measured according to ASTM D1003. -Refractive index and Abbe number: Measured with an Abbe refractometer (manufactured by Atago). -Glass transition temperature: After dissolving the polymer in methylene chloride, the solution was poured into methanol with stirring to precipitate the polymer, which was separated by filtration and dried to obtain a white powdery polymer. Using this, a differential scanning calorimeter (DSC: PerkinElmer D
SC-7 type). Haze value: Measured using a haze meter (manufactured by Suga Test Instruments) according to ASTM D1003. The results are shown in Table 1.

Examples 2 to 5 Comparative Examples 1 to 3 Molded articles were prepared in the same manner as in Example 1 except that the compositions of TCDMA, styrene, and methyl methacrylate were varied, and the physical properties were evaluated. 1 and Table 2.

[0036]

[0037]

[Table 1]

[0038]

[Table 2]

Examples 6 to 8 and Comparative Examples 4 to 6 In the same manner as in Example 1 except that the amounts of perroyl L, perbutyl O and perhexa 3M were varied in the composition of 280 g of TCDMA, 700 g of styrene and 420 g of methyl methacrylate. A molded article was prepared, and its physical properties were evaluated. The results are shown in Table 3.

[0040]

[Table 3]

[0041]

According to the present invention, it is possible to obtain an injection-moldable thermoplastic resin having a low haze value, high transparency, and excellent heat resistance. The resin is suitable for optical materials, especially lenses for glasses and the like.

Continuation of the front page (56) References JP-A-62-246001 (JP, A) JP-A-62-246914 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 212 / 08 C08F 220/14 C08F 220/18 G02B 1/04 G02C 7/02 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1 to 10 parts by weight of tricyclo [5,2,1,0 ^2,6 ] dec-8-yl methacrylate, 40 to 60 parts by weight of styrene and 10 to 40 parts of methyl methacrylate
Parts by weight are 100 parts by weight in total, and t (1/2) is 55 to 55 parts by weight.
The heat is characterized by polymerization in the presence of an initiator a at 69 ° C., an initiator b at t (１ ／) of 70 to 85 ° C. and an initiator c at t (ｃ) of 86 to 170 ° C. Manufacturing method of plastic resin. (However, t (1/2) is the decomposition temperature at which the half life is 10 hours) 2. The method for producing a thermoplastic resin according to claim 1, wherein (initiator b + initiator c) / initiator a (weight ratio) is used as 0.5 or more. 3. The initiator a is lauryl peroxide, the initiator b is t-butylperoxy-2-ethylhexanoate, and the initiator c is 1,1-bis (t-butylperoxy). 3. The method for producing a thermoplastic resin according to claim 1, which is 3,3,5-trimethylcyclohexane.