JP3214002B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition comprising an N-alkyl-substituted maleimide-olefin copolymer and an inorganic and / or organic filler, having a light diffusing property and having excellent heat resistance and rigidity. Things.

[0002]

2. Description of the Related Art Conventionally, synthetic resins having a light diffusing property have been widely used for lighting covers, various signboards, displays and the like. This is a material in which inorganic or organic fine particles are dispersed in a transparent resin. As the transparent resin, methacrylic resin, polystyrene, vinyl chloride resin, or the like is used. However, such materials have low heat resistance and rigidity, and are limited in use.

[0003] Various studies have been made on maleimide copolymers because of their high heat resistance. For example, a method of copolymerizing N-aromatic substituted maleimide with methyl methacrylate is disclosed in JP-B-43-9753, JP-A-61-14.
JP-A-17-6891, JP-A-61-171708 and JP-A-62-109811 disclose a method of copolymerizing an N-aromatic substituted maleimide with a styrene resin. It is disclosed in JP-A-61-76512 and JP-A-61-276807. However, the resins obtained by these methods have better heat resistance as the content of the N-aromatic substituted maleimide increases, but are very brittle, have poor processability, and have problems such as discoloration. Is not used.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resin composition having light diffusivity, excellent heat resistance and rigidity.

[0005]

The present inventors have made intensive studies in view of this problem, and as a result, have found that a resin composition comprising an N-alkyl-substituted maleimide-olefin copolymer and an inorganic and / or organic filler according to the present invention. Found that the above object was satisfied, and completed the present invention.

That is, according to the present invention, a) the following component (I) is 30 to 98 mol% of the whole polymer, and component (II) is 70 to 2 mol% of the whole polymer; Molecular weight of 1 × 10 ³ or more and 5 × 1
0 ⁶ or less resin and b) an inorganic (where glass filler
) And / or an organic filler, the content of which is a) / b) = 50 / 50-99.
9 / 0.1 and the refractive index difference between a) and b) is 0.005
The present invention relates to a resin composition characterized by the above.

[0007]

Embedded image (Where R ¹ represents an alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms)

[0008]

Embedded image (Where R ² , R ³ and R ⁴ are hydrogen or carbon 1
The resin composition of the present invention has light diffusibility and has excellent heat resistance, rigidity and weather resistance. Hereinafter, the present invention will be described in detail.

The resin constituting the resin composition of the present invention a)
Can be obtained, for example, by a radical copolymerization reaction between an N-alkyl-substituted maleimide that gives the component (I) and an olefin that gives the component (II).

Here, the N-alkyl-substituted maleimides that provide the component (I) include N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, Ni-propylmaleimide, and Nn-maleimide. Butylmaleimide, Ni-butylmaleimide, Ns-butylmaleimide, Nt-butylmaleimide, Nn-pentylmaleimide, Nn-hexylmaleimide, Nn-
Heptylmaleimide, Nn-octylmaleimide, N
Lauryl maleimide, N-stearyl maleimide, N
Specific examples include -cyclopropylmaleimide, N-cyclobutylmaleimide, N-cyclohexylmaleimide, and the like having 1 to 6 carbon atoms, particularly N-methylmaleimide, N-ethylmaleimide, N- Isopropyl maleimide or N-cyclohexyl maleimide is preferred. Furthermore, these can be used alone or in combination of two or more.

The olefins which provide the component (II) include ethylene, isobutene, 2-methyl-1
-Butene, 2-methyl-1-pentene, 2-methyl-1
-Hexene, 1-methyl-1-heptene, 1-isooctene, 2-methyl-1-octene, 2-ethyl-1-pentene, 2-methyl-2-butene, 2-methyl-2-pentene, 2-methyl And olefins such as -2-hexene. Of these, isobutene is preferably used from the viewpoint of mechanical properties and heat resistance. These can be used alone or in combination of two or more.

The content of component (I) is from 30 to 98 mol%, preferably from 40 to 85 mol%, and more preferably from 4 to 85 mol% of the whole polymer.
5-75 mol% is preferred. If the amount of the component (I) exceeds 98 mol%, the formed polymer becomes brittle, and
If the amount is less than mol%, the heat resistance of the polymer is undesirably reduced. In addition, the content of these constituent components can be determined as appropriate by adjusting the amounts used, for example, when reacting the above-mentioned compounds.

If necessary, other vinyl monomers can be copolymerized as long as the object of the present invention is not impaired. Other vinyl monomers include styrene, α
-Methylstyrene, vinyltoluene, 1,3-butadiene, isoprene and halogen-substituted derivatives thereof,
Methacrylic acid, methyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate,
Methacrylic acid derivatives such as triethoxysilylpropyl methacrylate, acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, phenyl acrylate and benzyl acrylate, vinyl esters such as vinyl acetate and vinyl benzoate, Methyl vinyl ether,
Vinyl ethers such as ethyl vinyl ether, propyl vinyl ether and butyl vinyl ether; vinyl chloride;
One or more compounds selected from vinylidene chloride, maleic anhydride, N-phenylmaleimide, N-carboxyphenylmaleimide, and acrylonitrile.

For the polymerization of these monomers, any of known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization can be employed.

Examples of the polymerization initiator include benzoyl peroxide, lauryl peroxide, octanoyl peroxide, acetyl peroxide, di-tert-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, and t-butyl peroxyacetate.
Or an organic peroxide such as t-butylperoxybenzoate, or 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-butyronitrile), 2,2 ′ -Azobisisobutyronitrile, dimethyl-2,2'-azobisisobutyrate, 1,1'-
An azo initiator such as azobis (cyclohexane-1-carbonitrile) is exemplified.

Solvents usable in the solution polymerization method include benzene, toluene, xylene, ethylbenzene,
Cyclohexane, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, dimethylformamide,
Isopropyl alcohol, butyl alcohol and the like can be mentioned.

The polymerization temperature can be appropriately set in accordance with the decomposition temperature of the initiator, but is generally preferably in the range of 40 to 300 ° C.

The above resin can also be obtained by post-imidizing a resin obtained by copolymerizing maleic anhydride and an olefin with an alkylamine or the like.

Such a post-imidization reaction is carried out, for example, by reacting a maleic anhydride-isobutene copolymer in a molten state or an alcohol such as methanol, ethanol or propanol.
Dissolved or dispersed in an aromatic solvent such as benzene, toluene, etc.
The reaction is performed at a temperature of 00 to 350 ° C.

Here, the weight average molecular weight (Mw) of the produced resin is determined by gel permeation chromatography.
(GPC). The molecular weight of the maleimide copolymer is 1 × 10 ³ or more and 5 × 10 ⁶ or less, especially 1
Those having a size of × 10 ⁵ or more and 1 × 10 ⁶ or less are preferable. When the molecular weight exceeds 5 × 10 ⁶ , the moldability deteriorates and 1 ×
If it is less than 103, the obtained resin tends to be brittle.

The maleimide copolymer, for example, tends to cause coloring if the residual monomer is present in the polymer, and the amount of the residual monomer is 3% by weight or less, preferably 1% by weight or less, particularly 0.1% by weight. The following is preferred. In order to obtain a molded article having good whiteness, the resin composition of the present invention was measured with a color computer (manufactured by Suga Test Instruments Co., Ltd.) using a test piece having a thickness of 0.8 mm. Yellowness (YI; reflection method) is 20 or less, preferably 10 or less,
It is particularly preferable that the resin be 5 or less.

The inorganic material used in the resin composition of the present invention (however,
Glass fillers) and / or organic fillers are substances whose refractive index differs from the substrate by 0.005 or more , for example, silica, barium sulfate, calcium carbonate, quartz, titanium oxide, zinc oxide, aluminum hydroxide, magnesium hydroxide, Examples include inorganic particles such as magnesium carbonate and calcium phosphate, polymer particles of a copolymer of an aromatic vinyl compound and a polyfunctional vinyl compound, and silicon-based particles.The surface of these fillers is vinylsilane, inosilane, or titanate-based coupling agent. Surface treatment may be performed.

The shape of these fillers may be in the form of particles, fibers, plates, etc., but particles are preferred.
The particle size of the filler is 0.1 to 60 μm, preferably 0.5
It is preferably from 30 to 30 μm, particularly preferably from 1 to 20 μm.

The resin composition of the present invention comprises the resin a) N
-Alkyl-substituted maleimide-olefin copolymers and b)
The content (weight ratio) of the inorganic (excluding the glass filler) and / or the organic filler is 50/50 to 99.
9 / 0.1 , especially 60 / 40-99.5 / 0.
5 , more preferably in the range of 70/30 to 99/1 . The difference in refractive index between a) and b) is 0.005 or more, and particularly preferably 0.01 or more, and the resin composition obtained by this difference in refractive index imparts light diffusibility.

When the resin of the present invention is used, various dyes, pigments, heat stabilizers such as hindered phenols and organic phosphates, and ultraviolet rays such as benzotriazole or hindered amine are used. Stabilizers, flame retardants, flame retardant aids, foaming agents, antistatic agents, various lubricants, and the like may be added.

Further, the method for producing the resin composition of the present invention is not particularly limited.
A method in which an alkyl-substituted maleimide-olefin copolymer is mixed with an inorganic and / or organic filler and other additives, or supplied to an extruder without mixing, and melt-kneaded.

The method of molding the resin composition of the present invention is not particularly limited, and ordinary molding methods such as injection molding, extrusion molding, blow molding and vacuum molding are applied.

[0028]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.

The molecular weight of the produced polymer was determined by GPC (Toso
It was determined in terms of polystyrene using HLC-802A manufactured by Co., Ltd.). The composition of the resulting polymer was determined primarily by elemental analysis. The refractive index was measured at room temperature using an Abbe refractometer (manufactured by Atago Co., Ltd.).

The yellowness of the polymer is 50 × 25 × 0.8 m
The evaluation was performed using a color computer (manufactured by Suga Test Instruments Co., Ltd.) using a m piece of press (reflection method; tristimulus value of reflector X: 79.44, Y = 82.22, Z; 94.5
1).

Using a small injection molding machine (Panejection, manufactured by Matsushita Electric Industrial Co., Ltd.), a test piece was prepared at a cylinder temperature of 240 to 300 ° C. and a mold temperature of 100 to 120 ° C.

The heat distortion temperature was measured according to ASTM D648, and the flexural strength and flexural modulus were measured according to ASTM D790.

The evaluation sample of the optical characteristics was obtained by using a single screw extruder (manufactured by Toyo Seiki Co., Ltd.) at a cylinder temperature of 240 to 270.
A sheet-like molded body having a thickness of 2 mm was prepared at a temperature of 275 ° C and a die temperature of 275 ° C.

For the light transmittance, an integrating sphere hardness tester (manufactured by Murakami Color Research Laboratory) was used. For the diffusivity, the molded product was placed 10 cm away from a 40 W fluorescent lamp (manufactured by Matsushita Electric Industrial Co., Ltd.). Judgment was made based on the presence or absence of a lamp image.

Example 1 In a 30 l autoclave equipped with a stirrer, nitrogen inlet tube, isobutene inlet tube, thermometer and degassing tube, 1180 g of N-methylmaleimide, 8 g of perbutyl neodecaneate and toluene / methanol Mixed solvent (1/1 weight ratio) 15
After littering and purging several times with nitrogen, 8.5 l of liquefied isobutene was charged and reacted at 60 ° C. for 12 hours.

The particulate polymer obtained by the reaction was separated by centrifugation and dried at 60 ° C. under reduced pressure for 24 hours. The yield was 1760 g.

From the results of elemental analysis of the obtained polymer, the maleimide unit in the produced polymer was 50 mol%, and the molecular weight (Mw) of the polymer was 272,000. Yellowness was 2.8 and refractive index was 1.527.

A test piece was prepared by adding 2.5% by weight of magnesium hydroxide fine particles having a particle size of 2 μm and a refractive index of 1.562 to the obtained polymer. Table 1 shows the evaluation results.

Example 2 A test piece was prepared in the same manner as in Example 1 except that 4% by weight of barium sulfate fine particles having a particle size of 3.1 μm and a refractive index of 1.636 were added to the same polymer as in Example 1. Table 1 shows the evaluation results.

Example 3 Using the same reactor as in Example 1, 1479 g of N-isopropylmaleimide, 8 g of perbutyl neodecaneate and 15 l of toluene were charged and purged several times with nitrogen.
8.5 l of liquefied isobutene was charged and reacted at 60 ° C. for 12 hours.

The reaction contents were precipitated in excess methanol, and the precipitated polymer was separated by centrifugation.
For 24 hours. Further, reprecipitation purification was carried out with a toluene / methanol solvent system. The yield was 1880 g.

From the results of elemental analysis of the obtained polymer, it was found that maleimide units and isobutene units in the produced polymer were 50 mol% and 50 mol%, respectively. The obtained polymer had a molecular weight (Mw) of 250,000, a yellowness of 3.0 and a refractive index of 1.519.

With respect to the obtained polymer, 4.0% by weight of calcium carbonate having a particle size of 6 μm and a refractive index of 1.658 and titanium oxide fine particles 1 having a particle size of 0.5 μm and a refractive index of 2.711 were used.
A test piece was prepared by adding weight%. Table 1 shows the evaluation results.

Comparative Example 1 Acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd .; Acrypet) was added with 4% by weight of barium sulfate fine particles having a particle size of 3.1 μm and a refractive index of 1.636, and a cylinder temperature of 210-2.
Pelleted at 40 ° C. Using the obtained pellets, injection test pieces were prepared at a cylinder temperature of 210 to 250 ° C. and evaluated. Table 1 shows the evaluation results.

[0045]

[Table 1]

[0046]

As is clear from the examples, the resin composition of the present invention has good light diffusion, and is excellent in heat resistance and rigidity. It is extremely useful in a wide range of applications such as fields, housing, medical, and food.

Claims (1)

(57) [Claims] 1. a) Component (I) shown below is 30 to 98 mol% of the whole polymer, component (II) is 70 to 2 mol% of the whole polymer, and the weight average molecular weight in terms of polystyrene is 1 It is composed of a resin of not less than × 10 ^{3 and not} more than 5 × 10 ⁶ and b) an inorganic (excluding glass filler) and / or an organic filler, and the content thereof is expressed as a weight ratio of a) / b) = 50/50 to 99.9 / 0.1 ,
A resin composition, wherein the difference in refractive index between a) and b) is 0.005 or more. Embedded image (Where R ¹ represents an alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms) (Where R ² , R ³ and R ⁴ are hydrogen or C 1 -C
8 represents an alkyl group)