JP3145774B2 - Antistatic methacrylic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a methacrylic resin composition having excellent antistatic properties.

[0002]

2. Description of the Related Art Methacrylic resins have excellent transparency and gloss, and possess excellent mechanical properties, workability, light resistance, etc., and are widely used in various lighting equipment, decorative articles, nameplates, etc. Used. However, the methacrylic resin has a strong chargeability, and thus has a drawback such as attachment of dust and dust in the air to impair the appearance.

[0003] had to solve these drawbacks, for example, methacrylic how resin adding an appropriate amount of the higher fatty acid monoglyceride and polyalkylene glycols and phosphorous acid ester (Tokuoyake Sho 53-15896), an alkylene oxide group how kneading a polymer of a vinyl compound,
A method of blending a copolymer in which a polar group such as a sulfonate is introduced into a molecule (Japanese Patent Laid-Open No. 1882837/1984).
And kneading an alkyl sulfonate (Japanese Patent Application Laid-Open
No. 24845) has been proposed.

In these methods, excellent antistatic performance can be imparted to a methacrylic resin, but the range of molding conditions under which antistatic performance is sufficiently exhibited is narrow, and the size and shape of a molded product are limited. There are problems such as limitations, low antistatic performance in practice, and even if the effect is effective, the molded product will be colored yellow, and the additive will have an unpleasant odor remaining on the molded product. Is currently limited.

[0005]

Accordingly, an object of the present invention is to provide an antistatic methacrylic resin composition having an excellent antistatic effect and having excellent heat resistance, mechanical properties, and molding conditions. To provide.

[0006]

The present inventors have SUMMARY In order to achieve the above, the result of intensive studies to achieve the object, the particular phosphorus compound and grayed Riserinmono fatty acid esters, or further methacrylic resin composition containing a polyalkylene glycol By adding specific fine particles in a specific amount, an excellent antistatic effect that cannot be obtained by adding only additives is obtained, and the mechanical strength and heat resistance characteristic of methacrylic resin are maintained. And completed the present invention.

[0007] That it is an aspect of the present invention, the 100 parts by weight of methacrylic resin, grayed Riserinmono fatty acid ester 0.5 to 6 parts by weight, formula (1)

[0008]

Embedded image (Wherein R ₁ , R ₂ , and R ₃ represent an alkyl group or an aryl group having 6 to 22 carbon atoms), and 0.05 to 4 parts by weight of a phosphorus compound represented by the following formula: .
This is achieved by an antistatic methacrylic resin composition obtained by blending 0.5 to 80 parts by weight of 5 μm fine particles. Hereinafter, the present invention will be described in detail.

The methacrylic resin used in the present invention comprises:
Methyl methacrylate alone or a methacrylic resin obtained by polymerizing a monomer mixture of at least one kind of other monomer copolymerizable with methyl methacrylate and methyl methacrylate, and having excellent mechanical properties. In order to maintain balanced moldability, methacrylic resin at 20 ° C
The intrinsic viscosity in chloroform is 0.30 to 1.0 (dl /
g), and a particularly preferred intrinsic viscosity is 0.4 to 0.9 d.
1 / g.

Examples of other copolymerizable monomers include acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate, ethyl methacrylate, cyclohexyl methacrylate, tricyclodecyl methacrylate and methacrylic acid. Examples thereof include methacrylic acid esters except methyl methacrylate such as tribromophenyl acid, vinyl compounds such as acrylonitrile, methacrylonitrile, styrene and vinyltoluene, and maleimide compounds such as o-chlorophenylmaleimide and cyclohexylmaleimide. The ratio of copolymerization of these other copolymerizable monomers is not particularly limited, but is preferably 60% by weight, preferably 50% by weight or less in order to maintain the mechanical properties characteristic of methacrylic resins. is there. These are known polymerization techniques (continuous) bulk polymerization, suspension polymerization, emulsion polymerization,
Polymerization may be performed by any method of solution polymerization.

[0011] glycerin mono-fatty acid ester and the phosphorus compound used in the present invention is required to impart antistatic properties, by using in combination these additives, the first time the antistatic effect can be obtained.

Examples of the glycerin monofatty acid ester include glycerin monostearate, glycerin monocaprate, glycerin monolaurate, glycerin monopalmitate, and glycerin monobehenate. Particularly preferred glycerin monofatty acid ester is glycerin monofatty acid ester. Stearate, glycerin monobehenate. These glycerin mono fatty acid esters
It's added pressure amount, relative to 100 parts by weight of methacrylic resin, glycerin mono-fatty acid ester le 0. 5-6 parts by weight
Is necessary, and preferably 1 to 5 parts by weight. If the added amount exceeds 6 parts by weight, bleeding occurs after molding and the appearance is impaired, and the surface of the mold during molding is undesirably disadvantageous. If the addition amount is less than 0.5 part by weight, the manifestation of antistatic performance is insufficient, which is not preferable.

The phosphorus compound represented by the formula (1) used in the present invention is, for example, tributyl phosphite, triisooctyl phosphite, tribenzyl phosphite, triphenyl phosphite, phenyldidecyl phosphite, diphenyl isophosphite. Examples include decyl phosphite, trisnonylphenyl phosphite, tridecyl phosphite, and tristearyl phosphite. Particularly preferred phosphorus compounds are tridecyl phosphite and tristearyl phosphite. The addition amount of the phosphorus compound will require an 0.05 to 4 parts by weight der Rukoto, preferably 1 to 3 parts by weight. If the added amount exceeds 4 parts by weight, disadvantages such as adhesion to a mold and soiling of a molded product, which impair the appearance, are not preferred. If the addition amount is less than 0.05 part by weight, the effect of antistatic performance is low, which is not preferable.

[0014] Oite the present invention, the polyalkylene apples recall, in conjunction with glycerin mono-fatty acid ester and the phosphorus compound, more effectively expressed antistatic performance than with the combination of glycerin mono-fatty acid ester and a phosphorus compound I do. For example, polyethylene glycol and polypropylene glycol are mentioned, and their molecular weight is 20.
It is 0 to 1500, more preferably 300 to 1000. When the molecular weight is less than 200, compatibility with the resin is poor and bleeding is easy. When it exceeds 1500, the antistatic effect is low, which is not preferable. The addition amount of these polyalkylene glycols is 0.5 to 5 parts by weight, preferably 1 to 4 parts by weight. If the amount exceeds 5 parts by weight, bleeding occurs, which is not preferable.

In the present invention , the fine particles can be used in combination with each of the above-mentioned additives, glycerin monofatty acid ester and a phosphorus compound, or further with a polyalkylene glycol, so as to obtain an antistatic property which cannot be obtained by the additives alone. Necessary for expressing the effect.
The average particle diameter of the fine particles will require an <br/> Oh Rukoto at 0.005 to 0.5 .mu.m, if the average particle diameter exceeds 0.5 [mu] m, although the antistatic effect is good, Light scattering is increased and transparency is reduced. Average particle size 0.005
If it is less than μm, the antistatic effect is not easily exhibited, which is not preferable. Rate of addition of Re This, methacrylic resin 10
0 parts by weight with respect to the required 0.5 to 80 parts by weight of Der Rukoto
There, good preferable added amount is 1 to 70 parts by weight. If the addition amount exceeds 80 parts by weight, the antistatic effect is but insufficient strength, also added the amount of the fine grains is less than 0.5 part by weight
It is not preferable because the synergistic effect with the antistatic agent due to the addition of the particles is small .

As the fine particles used in the present invention, fine particles such as glass fine particles, inorganic compounds such as calcium carbonate and titanium oxide, conjugated diene rubbers such as polybutadiene, polyisoprene and SBR, or acrylate rubbers; Or fine beads made of various resins having a cross-linked structure, and fine beads made of a resin having an intrinsic viscosity of 1.5 dl / g or more in chloroform at 20 ° C. The same applies when these different fine particles are used in combination. The effect of is obtained. In addition, the structure of these fine particles may be either a uniform single-layer structure or a fine particle having a two- or three-layer structure, and a fine particle having a multilayer structure in which the composition of each layer is different.
There is no particular limitation.

Among these fine particles used in the present invention, particularly useful fine particles are fine particles which can maintain transparency and impart an antistatic effect, contain methyl methacrylate as a main component, and have a crosslinked structure. Or methacrylic microbeads containing methyl methacrylate as a main component and having an intrinsic viscosity of 1.5 dl / g or more in chloroform at 20 ° C. The ratio of copolymerizing these monomer mixtures is not particularly limited, but when the following ratios and types of monomers are used, more favorable results are obtained in terms of transparency.

That is, the fine beads having a crosslinked structure containing methyl methacrylate as a main component include 0 to 59% by weight of a monofunctional vinyl monomer unit copolymerizable with 40 to 99% by weight of a methyl methacrylate unit, and Polyfunctional vinyl monomer unit 1
Microbeads obtained by polymerizing a monomer mixture of 20 to 20% by weight, or 40 to 99% by weight of methyl methacrylate units
At least one inner layer obtained by polymerizing a monomer mixture of 0 to 59% by weight of a monofunctional vinyl monomer unit copolymerizable with 1 to 20% by weight of a polyfunctional vinyl monomer unit; It is a fine bead having a multilayer structure having an outermost layer formed by polymerizing a monomer mixture obtained by removing a polyfunctional vinyl monomer from a monomer. Examples of the copolymerizable monofunctional vinyl monomer used for these include acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate, methyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, and methacryl. Examples thereof include methacrylic esters such as tricyclodecyl acid and tribromophenyl methacrylate, vinyl compounds such as acrylonitrile, methacrylonitrile, styrene and vinyltoluene, and maleimide compounds such as o-chlorophenylmaleimide and cyclohexylmaleimide. Or, as the polyfunctional vinyl monomer, for example, allyl methacrylate, allyl acrylate, polyethylene glycol dimethacrylate,
Examples include polyethylene glycol diacrylate, trimethylolpropane triacrylate, divinylbenzene and butadiene, isoprene and the like.

The methyl methacrylate used in the present invention is a main component, and has an intrinsic viscosity in chloroform of 20 ° C. of 1.5.
A methacrylic fine bead having a dl / g or more is a monomer mixture of 40 to 100% by weight of a methyl methacrylate unit and 0 to 60% by weight of another vinyl monomer unit copolymerizable with methyl methacrylate. It is a fine bead obtained by polymerization, and as a copolymerizable monofunctional vinyl monomer other than methyl methacrylate, for example, acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate;
Methacrylates such as ethyl methacrylate, cyclohexyl methacrylate, tricyclodecyl methacrylate, tribromophenyl methacrylate, acrylonitrile, methacrylonitrile, styrene, vinyl compounds such as vinyltoluene, o-chlorophenylmaleimide, cyclohexylmaleimide And the like.

The fine particles used in the present invention are prepared by a suspension polymerization method,
Although it can be polymerized by a general known polymerization method such as an emulsion polymerization method,
There is no particular limitation. As a method for producing the methacrylic antistatic resin composition of the present invention, glycerin monofatty acid ester, phosphorus compound, and fine particles, or further polyalkylene glycol and methacrylic resin,
Mix with a commonly used mixer such as Brabender, Henschel mixer, tumbler, etc. and knead with an extruder to form pellets or sheets, or form a mixture or pellets with an injection molding machine, compression molding machine or extrusion molding machine. A method of forming a molded article with a processing machine can be used, and there is no particular limitation.

In carrying out the present invention, additives such as an ultraviolet absorber, a heat stabilizer, an antioxidant, a lubricant, a release agent, a dye and a pigment can be added as necessary. ,
Any time such as melting and kneading may be used.

[0022]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited by these examples. The antistatic performance in the examples was evaluated based on the following evaluation method.

1. Charge voltage, half-life: Honest meter S
-4104 (Shishido Shokai) 2. Surface resistivity: Surface resistivity meter TR-8601
(Takeda Riken) 3. 3. Intrinsic viscosity: Measured at 20 ° C. with an automatic viscometer after dissolving a certain concentration of resin in chloroform. Total light transmittance: according to ASTM D1003.

The fine beads used in the examples were polymerized by the method of Reference Example 1 shown below to obtain the fine beads shown in Table 1. In addition, the numbers of Table 1 shall be used for the fine beads in the examples.

The abbreviations used in Tables 1, 2 and 3 are as follows. MA: Methyl acrylate EA: Ethyl acrylate BA: Butyl acrylate ST: Styrene NPG: Neopentylglycol dimethacrylate AMA: Allyl methacrylate PEGM: Ethylene glycol dimethacrylate AA: Allyl acrylate TBP: Methacrylic acid Tribromophenyl CHMI: Cyclohexylmaleimide BM: Glycerin monobehenate PM: Glycerin monopalmitate SM: Glycerin monostearate LM: Glycerin monolaurate DP: Tridecyl phosphite SP: Tristearyl phosphite 3E: polyethylene glycol molecular weight 30
06E: polyethylene glycol molecular weight 60
0 10E: polyethylene glycol molecular weight 10
00 10P: Polypropylene glycol molecular weight 10
Reference Example 1 In a 5 L separable flask equipped with a stirrer and a reflux condenser, potassium persulfate was added as a polymerization initiator in an amount of 0.1 mL.
3.0 kg of pure water to which 1% by weight of sodium dioctyl sulfosuccinate as an emulsifier was added to adjust the particle size and 1.5 kg of the monomer mixture shown in Table 1 were charged, and N2 substitution was performed while stirring. Thereafter, polymerization was carried out at 70 ° C. After the exothermic peak, polymerization was carried out after 1 hour at 90 ° C. In this polymerization reaction, the monomers may be charged in a total amount of 1.5 kg in one or several divided portions. The fine beads of B2 and B3 in Table 1 are obtained by this method. Was polymerized. The obtained latex was added to 10 kg of a 1% by weight aqueous solution of calcium chloride at 50 ° C. with stirring, and the polymer was separated, washed and dried before use. The average particle diameter of the fine beads was measured using a dynamic light scattering photometer (DLS-700, manufactured by Otsuka Electronics Co., Ltd.).

[0026]

[Table 1] Example 1 98% by weight of methyl methacrylate, 2% by weight of methyl acrylate, and 100 parts by weight of a methacrylic resin having an intrinsic viscosity of 0.551 dl / g were mixed with glycerin monostearate (Exel T-95 manufactured by Kao Corporation). ) 4.5 parts by weight, tristearyl phosphite (Johoku Chemical Co., Ltd.)
1.5 parts by weight of JP-318E) and 5 parts by weight of the fine beads of B1 in Table 1 were mixed with a Henschel mixer, and the mixture was pelletized with an extruder (manufactured by Nakatani Machine) having a cylinder diameter of 40 mm. The pellets were mounted on an injection molding machine (N70A, manufactured by Nippon Steel Works) with a flat mold (200 L × 70 W × 3 t (mm)), and molded at a cylinder temperature of 240 ° C. and a mold temperature of 45 ° C. As a result of measuring the charged voltage, half-life and surface resistivity of the formed flat plate, the maximum charged voltage was 350 V and the half-life was 1 sec.
c. Hereinafter, the surface specific resistance was 3.5 × 10 ¹² Ω, showing good antistatic performance.

Comparative Example 1 Methyl methacrylate 98% by weight, methyl acrylate 2% by weight, intrinsic viscosity 0.551
A dl / g methacrylic resin was pelletized in the same manner as in Example 1. Using the pellets, evaluation was performed in exactly the same manner as in Example 1. As a result of measuring the charged voltage, half-life, and surface resistivity of the formed flat plate, the maximum charged voltage was 55
0 V, half-life is not measured because it does not decay, the surface resistivity is 3.8 × 10 ¹⁶ or more, and there is no antistatic performance.

(Comparative Example 2) Methyl methacrylate 98% by weight, methyl acrylate 2% by weight, intrinsic viscosity 0.551
Glycerin monostearate (Exel T-95 manufactured by Kao Corporation) was added to 100 parts by weight of a dl / g methacrylic resin.
Example 1 4.5 parts by weight and 1.5 parts by weight of tristearyl phosphite (JP-318E manufactured by Johoku Chemical Co., Ltd.)
And pelletized in exactly the same manner. Using the pellets, evaluation was performed in exactly the same manner as in Example 1. As a result of measuring the charged voltage, half-life and surface resistivity of the molded flat plate, the maximum charged voltage was 470 V, and the half-life was 1.5 sec. The surface resistivity is 128 × 10 ¹² , and the antistatic performance is low but the performance is low.

Example 2 Methyl methacrylate 99.5
100 parts by weight of a methacrylic resin having an intrinsic viscosity of 0.458 dl / g, 3.5 parts by weight of glycerin monostearate (Exel T-95 manufactured by Kao Corporation), 1.5% by weight of tristearyl phosphite (JP-318E manufactured by Johoku Chemical Co., Ltd.) and polyethylene glycol having a molecular weight of 300 (polyethylene glycol # 300 manufactured by NOF Corporation) 2.4
5.42 Kg of a mixture obtained by mixing 1.0 part by weight of the fine beads of B2 in Table 1 with the above parts by weight was pelletized in the same manner as in Example 1. Using the pellets, evaluation was performed in exactly the same manner as in Example 1. As a result of measuring the charged voltage, half-life, and surface resistivity of the formed flat plate, the maximum charged voltage was 300.
V, half-life 1 sec. Below, the surface resistivity is 0.87 ×
At 10 ¹² Ω, very good antistatic performance was exhibited.

Comparative Example 3 Methyl methacrylate 99.5
100 parts by weight of a methacrylic resin having an intrinsic viscosity of 0.458 dl / g, 3.5 parts by weight of glycerin monostearate (Exel T-95 manufactured by Kao Corporation), 1.5% by weight of tristearyl phosphite (JP-318E manufactured by Johoku Chemical Co., Ltd.) and polyethylene glycol having a molecular weight of 300 (polyethylene glycol # 300 manufactured by NOF Corporation) 2.4
5.37 kg of the weight part was pelletized in the same manner as in Example 1. Using the pellets, evaluation was performed in exactly the same manner as in Example 1. Charged voltage, half-life,
As a result of measuring the surface resistivity, the maximum charged voltage was 420 V,
Half-life 1 sec. Below, the surface resistivity is 98 × 10 ¹² Ω
The antistatic performance is maintained but the performance is low. (Example 3) To 100 parts by weight of a parapet GR (GR-08670 manufactured by Kuraray Co., Ltd.) containing an acrylate rubber, 3.5 parts by weight of glycerin monostearate (Exel T-95 manufactured by Kao Corporation) 1. 1.5 g of tristearyl phosphite (JP-318E manufactured by Johoku Chemical Co., Ltd.) and polyethylene glycol having a molecular weight of 300 (polyethylene glycol # 300 manufactured by NOF Corporation)
6 kg of the mixture of 4 parts by weight was pelletized in the same manner as in Example 1. Using the pellets, evaluation was performed in exactly the same manner as in Example 1. As a result of measuring the charged voltage, half-life, and surface resistivity of the formed flat plate, the maximum charged voltage was 360.
V, half-life 1 sec. Hereinafter, the surface resistivity is 1.37 ×
At 10 ¹² Ω, very good antistatic performance was exhibited.

(Examples 4 to 8) A methacrylic resin having a composition shown in Table 2 was mixed with a glycerin monofatty acid ester, a phosphorus compound, a polyalkylene glycol in the proportions shown in Table 2 and the fine beads shown in Table 1. The additives were mixed, and the mixture was pelletized and formed in the same manner as in Example 1,
An evaluation was performed. As shown in Table 2, the pellets to which the fine beads were added had a low maximum charged voltage, a half-life of 1 second or less, and good results in terms of surface resistivity.

[0032]

[Table 2] (Comparative Examples 4 to 8) The methacrylic resin having the composition shown in Table 3 was mixed with the glycerin monofatty acid ester, the phosphorus compound, and the polyalkylene glycol in the proportions shown in Table 3, and the mixture was used in Examples. Pelletization, molding, and evaluation were performed in exactly the same manner as in Example 1. As shown in Table 3, the pellets to which fine particles were not added had a high maximum charged voltage, a high surface resistivity, and had an antistatic performance as compared with a normal methacrylic resin, but were compared with the examples. Then, there is a clear difference in antistatic performance.

[0033]

[Table 3] (Example 9) 99.5% by weight of methyl methacrylate, 0.5% by weight of methyl acrylate, intrinsic viscosity 0.458dl
Glycerin monostearate (Exel T-95 manufactured by Kao Corporation) in 100 parts by weight of a methacrylic resin / g / g.
5 parts by weight, 1.5% by weight of tristearyl phosphite (JP-318E manufactured by Johoku Chemical Co., Ltd.) and a molecular weight of 3
2.4 parts by weight of polyethylene glycol (polyethylene glycol # 300 manufactured by NOF Corporation) and 5 parts by weight of fine particles made of SiO2 (Aerosil # 200, manufactured by Nippon Aerosil Co., Ltd.) having an average particle size of 0.012 μm. 5.42 Kg of the mixed mixture was pelletized in the same manner as in Example 1. Using the pellets, evaluation was performed in exactly the same manner as in Example 1. As a result of measuring the charged voltage, half-life, and surface resistivity of the molded flat plate, the maximum charged voltage was 320
V, half-life 1 sec. Hereinafter, the surface resistivity is 1.32 ×
At 10 ¹² Ω, very good antistatic performance was exhibited.

[0034]

As described above, since the antistatic methacrylic resin composition of the present invention is excellent in antistatic performance, the obtained molded article is impaired in appearance due to dirt such as dust. Since it has no light scattering effect and has an appropriate light diffusion effect, it is suitably used in fields such as lighting equipment such as louvers, meter covers requiring antireflection performance, and decorative articles.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-51-49246 (JP, A) JP-A-54-74849 (JP, A) JP-A-62-220502 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08L 33/10 C08K 5/11 C08K 5/524 C08K 7/00

Claims (4)

(57) [Claims] A glycerol monofatty acid ester is used in an amount of 0.5 to 6.0 parts by weight based on 100 parts by weight of a methacrylic resin, and has the following general formula (1). (Wherein R ₁ , R ₂ , and R ₃ represent an alkyl group or an aryl group having 6 to 22 carbon atoms), and 0.05 to 4 parts by weight of a phosphorus compound represented by the following formula:
An antistatic methacrylic resin composition obtained by mixing 0.5 to 80 parts by weight of 5 μm fine particles. 2. The methacrylic resin composition according to claim 1,
An antistatic methacrylic resin composition further comprising 0.5 to 5.0 parts by weight of a polyalkylene glycol. 3. A fine particle having an average particle diameter of 0.005~0.5μm is, claim 1 or 2 antistatic methacrylic resin composition according a fine beads having a crosslinked structure. 4. The fine beads having an average particle diameter of 0.005 to 0.5 μm are fine beads having an intrinsic viscosity of 1.5 dl / g or more in chloroform at 20 ° C.
Or the antistatic methacrylic resin composition according to 2.