JPH09227785A - Resin composition and formed material therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition excellent in antistatic property and surface appearance, and useful for a covering member for protecting a light source of a lighting utensil by blending a specific polyether and an alkylsulfonic acid salt with a transparent resin in a specific ratio. SOLUTION: This resin composition is obtained by blending (A) 100 pts.wt. transparent resin such as a methacrylic resin with (B) 0.01-10 pts.wt. polyether of the formula [R<1> is H or CH3 ; (n) is a number decided by mean molecular weight thereof] having 2,000-50,000 number averaged molecular weight, (C) 0.1-5 pts.wt. compound of the formula: R<2> -SO3 M [R<2> is an 8-18C (branched) alkyl; M is an alkali metal] and (D) 0.5-20 pts.wt. white-type inorganic compound particles having 0.1-20μm weight averaged particle diameter (e.g. calcium carbonate particles and barium sulfate particles).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having excellent antistatic properties and surface appearance, which is used as a cover member for protecting a light source in various lighting devices, and a molded product thereof.

[0002]

2. Description of the Related Art Fine particles having different refractive indices are dispersed in a transparent resin for a cover member for protecting a light source in various lighting equipment such as home lighting, facility lighting, store display lighting, and vehicle interior / exterior lighting. In addition, a resin composition or a molded article having both light transmittance and light diffusion properties is used. However, these general transparent resins have a large surface resistivity, so static electricity induced by contact, friction, etc. is hard to be lost, and when used as a light source protection cover, dust etc. adheres to the transparent resin and deteriorates the aesthetics and optical properties. There is a drawback that it causes deterioration of characteristics.

Conventionally, in order to eliminate such electrostatic damage, for example, a method of blending an acrylic resin, which is a transparent resin, with an alkali metal salt of alkylsulfonic acid or alkylbenzenesulfonic acid and glycerin fatty acid ester (JP-A-1-197552). Alternatively, a method of blending a methacrylic resin with an alkali metal salt or alkaline earth metal salt of an alkyl sulfonic acid and a thioether-based antioxidant (JP-A-4-680).
45) and the like are disclosed, and it is known that a resin composition having an antistatic property can also be obtained by those methods.

[0004]

However, when a resin molded product used for a protective cover member of various lighting devices is produced by using the resin composition obtained by these methods, a light diffusing agent to be added for diffusing light. And poor appearance of the surface due to poor dispersion of the antistatic agent and generation of fine patterns and agglomerates on the surface, which lowers the lighting effect and causes a problem in that the appearance is not preferable.

On the other hand, if an antistatic agent of a specific type and addition amount is used with an emphasis on the surface appearance, another problem arises in that sufficient antistatic performance cannot be obtained. An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a resin composition which can be used as a light source protective cover member for various lighting devices having excellent antistatic properties and surface appearance at the same time, and a molded product thereof. There is something to do.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that a transparent resin has a polyether of a specific molecular weight and an alkali metal alkyl sulfonic acid having an alkyl group with a carbon number in a specific range. The present invention has been completed by finding that a resin composition having excellent antistatic property and surface appearance at the same time can be obtained by containing a specific amount of a salt and a white inorganic compound particle having a weight average particle size in a specific range. . That is, the present invention has (a) 100 parts by weight of a transparent resin, (b) a number average molecular weight represented by the following formula (1) of 2,000 to 50,
0.01 to 10 parts by weight of polyether,

[0007]

Embedded image (However, R ¹ is H or CH ₃ , and n is a constant determined by the average molecular weight.) (C) Alkyl having an average carbon number of the alkyl group represented by the following formula (2) within the range of 10 to 18 0.1 to 5 parts by weight of an alkali metal salt of sulfonic acid,

[0008]

Embedded image (However, R ² is a C _{8 to} C ₁₈ straight-chain or branched alkyl group, and M is an alkali metal.) (D) At least one or more kinds having a weight average particle diameter of 0.1 to 20 μm. White inorganic compound particles 0.5 to 20
And a resin composition.

Another aspect of the present invention is a molded product obtained by molding the above resin composition into an arbitrary shape, wherein at least one surface has an arithmetic average roughness (R _a ) of 1 μm or less. is there. Further, the present invention is a resin molded product having a structure in which a layer made of the above resin composition is laminated in a thickness of 5 to 200 μm on at least one surface of a base member made of a transparent resin. Further, in the present invention, calcium carbonate or barium sulfate is preferably used as the white inorganic compound, and methacrylic resin is preferably used as the transparent resin.

Hereinafter, the present invention will be described in detail. The transparent resin used in the present invention is defined as a substance having a haze of 10% or less measured according to JIS K-7105. Specific examples include methacrylic resin, polycarbonate resin, polystyrene resin, styrene-methyl methacrylate copolymer resin, styrene-butadiene copolymer resin, amorphous polyolefin resin, polyvinyl chloride resin and the like. Methacrylic resin is particularly preferably adopted.

The methacrylic resin which can be used in the present invention includes a resin mainly composed of methyl methacrylate, such as a homopolymer of methyl methacrylate, or methyl methacrylate and methyl acrylate, ethyl acrylate,
n-propyl acrylate, isopropyl acrylate, butyl acrylate, acrylonitrile, acrylic acid, methacrylic acid, vinyl pyridine, vinyl morpholine, vinyl pyridone tetrahydrofurfuryl acrylate, N, N-dimethylaminoethyl acrylate, N,
N-dimethylacrylamide, 2-hydroxyacrylate, ethylene glycol monoacrylate, glycerin monoacrylate, maleic anhydride, styrene, or a copolymer with one or more copolymerizable monomers such as α-methylstyrene, and Heat-resistant acrylic resins, low-hygroscopic acrylic resins, and the like are included. These may be used alone or may be blended.

An impact-resistant acrylic resin is used in order to maintain transparency and have impact resistance at the same time, and its rubber elastic body is disclosed in JP-A-53-58554 and 55-94.
Nos. 917 and 61-32346. Briefly, it is a multi-stage polymer produced by a multi-stage sequential polymerization method in which an elastic layer and an inelastic layer are alternately formed around an acrylic polymer core material.

These resins can be obtained by known polymerization methods such as bulk polymerization method, suspension polymerization method, emulsion polymerization method and solution polymerization method. As the shape of the resin, so-called pellets, powders, beads, or pulverized amorphous materials can be used.

The polyether used in the present invention has a structural unit represented by the following general formula (1). Ordinary polyether has a hydroxyl group at the terminal of the molecular chain, but it is also possible to use a derivative having a methoxy group at both ends or one end, or an ester type with an organic acid such as fatty acid.

[0015]

Embedded image (However, R ¹ is H or CH ₃ , and n is a constant determined by the average molecular weight.)

Specific examples of the polyether used in the present invention include polyethylene oxide, polyethylene glycol, polypropylene oxide, polypropylene glycol, methoxy polyethylene glycol, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene oxide-polypropylene glycol block. Examples thereof include copolymers and ethylene oxide-propylene oxide copolymers.

The number average molecular weight of the polyether used in the present invention is preferably in the range of 2,000 to 50,000. When the number average molecular weight is in the range of 2,000 to 50,000, it is extremely preferable in that it can be contained in the transparent resin to effectively provide antistatic performance. The number average molecular weight of the polyether can be obtained from a distribution curve obtained by dissolving the polyether in an arbitrary solvent and measuring the molecular weight distribution using a general instrumental analysis method such as liquid chromatography.

The amount of the polyether used in the present invention is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the transparent resin. This is because the addition amount of 0.01 to 10 parts by weight is preferable in that the physical properties such as mechanical strength and heat resistance of the resin composition obtained by being contained in the transparent resin are not deteriorated.

The alkali metal salt of an alkyl sulfonic acid used in the present invention is represented by the following general formula (2), and the average carbon number of the alkyl group is preferably within the range of 10-18. If the average carbon number is in the range of 10 to 18, the carbon number of the alkyl group may show a distribution, and the structure of the alkyl group may be linear or branched. When the carbon number average value of the alkyl group is within the above range, it is very preferable in that the combined effect of providing antistatic property when incorporated in the transparent resin and not deteriorating the surface appearance is exhibited.

[0020]

[Chemical 6] (However, R ² is a C _{8 to} C ₁₈ linear or branched alkyl group, and M is an alkali metal.)

The average carbon number of the alkyl group is obtained by dissolving an alkali metal salt of alkylsulfonic acid in an arbitrary solvent and measuring a mass spectrum by mass spectrometry combined with various ionization methods. It can be calculated from the distribution intensity. In addition, the above-mentioned alkali metal salt of alkylsulfonic acid is sodium as an alkali metal,
Lithium, potassium and the like are preferably used.

Specific examples of the alkali metal salt of alkyl sulfonic acid used in the present invention include sodium octyl sulfonate, lithium octyl sulfonate, potassium octyl sulfonate, sodium isooctyl sulfonate, sodium nonyl sulfonate, decyl sulfonic acid. Examples thereof include sodium, lithium decyl sulfonate, sodium dodecyl sulfonate, lithium dodecyl sulfonate, sodium tetradecyl sulfonate, sodium pentadecyl sulfonate, sodium hexadecyl sulfonate, sodium octadecyl sulfonate, and mixtures thereof.

The amount of the alkali metal salt of alkyl sulfonic acid used in the present invention is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the transparent resin. Addition amount is 0.1-5
This is because when the content is within the range of parts by weight, side effects such as stains and stickiness do not occur on the surface of the resin composition or molded product obtained by being contained in the transparent resin, which is preferable.

The white inorganic compound used in the present invention is
At least one selected from those having a weight average particle diameter in the range of 0.1 to 20 μm is preferable. The particle size distribution of the inorganic compound particles can be measured by a known light transmission type sedimentation particle size distribution measuring method or the like, and the weight average particle size can be determined from the obtained distribution. Weight average particle size is 0.1-20μ
When it does not fall within the range of m, it can be used by classifying the particles so as to fall within the above range. When the weight average particle diameter of the inorganic compound particles is in the range of 0.1 to 20 μm, secondary aggregation of the particles does not occur when dispersed in the transparent resin, and it is preferable that the surface appearance does not deteriorate during molding. is there. Further, when the particle size is adjusted within the above particle size range, refraction and reflection of visible light at the interface of each particle are effectively generated, which is preferable in that optical characteristics suitable for use as a light source protective cover can be obtained.

Further, it is preferable that the white inorganic compound particles used in the present invention do not melt at the molding temperature of the transparent resin. If the transparent resin does not melt at the molding temperature, the shape and particle size will be maintained when dispersed in the transparent resin, and stable color tone and optical characteristics suitable for light source protection cover applications can be obtained. This is because it is preferable.

Specific examples of the white inorganic compound particles used in the present invention include calcium carbonate, calcium fluoride,
Potassium fluoride, barium sulfate, magnesium sulfate, titanium oxide, potassium titanate, aluminum hydroxide, magnesium hydroxide, crystalline silica, amorphous silica, glass flakes, glass fibers, alumina, mica, talc, clay and the like. These may be used alone or in combination of two or more. Particularly, calcium carbonate and barium sulfate are preferable in that they have excellent optical and color tone characteristics when kneaded with a transparent resin.

The amount of the white inorganic compound particles used in the present invention is 0.5 to 2 with respect to 100 parts by weight of the transparent resin.
It is preferably 0 part by weight. Within this range, it becomes possible to adjust the color tone without extremely lowering the optical characteristics when dispersed in a transparent resin, especially the total light transmittance, and it is preferable to apply it to a light source protection cover application.

The resin composition of the present invention contains other components, such as pigments, dyes, fillers, mold release agents, heat stabilizers, antioxidants, nucleating agents, etc., as long as the physical properties thereof are not impaired. A light stabilizer, an ultraviolet absorber, a plasticizer, etc. can be contained in any process.

The method for producing the resin composition according to the present invention is as follows:
A method in which the above polyether, an alkali metal salt of an alkyl sulfonic acid, and white inorganic compound particles are uniformly dispersed in a transparent resin is preferable. For example, a polymerizable monomer constituting the transparent resin or a partially polymerized polymerizable monomer is used. It can be obtained by a method of dispersing these contents in a body syrup and polymerizing, or a method of mixing the contents with a transparent resin previously polymerized, melt-kneading and extruding. The polyether and the alkali metal salt of alkylsulfonic acid may be mixed in advance. Further, the polyether in the resin composition, the alkali metal salt of an alkyl sulfonic acid, and the content of each of the white inorganic compound particles may be a predetermined amount,
The concentration may be increased to form a masterbatch.

In the present invention, when a molded product is obtained using the above resin composition, it is preferable that at least one surface of the molded product has an arithmetic average roughness (R _a ) of 1 μm or less. More preferably, R _a is 0.8 μm or less. R
_{When a} is more than 1 μm, irregularities on the surface can be visually confirmed and light is scattered on the surface. Therefore, when applied to a light source protection cover member, problems such as deterioration of appearance and deterioration of lighting effect occur, which is not preferable. For the measurement of Ra, _a sheet-like material having a thickness of, for example, 1 to 5 mm is used as the resin composition, and JIS
It can be performed using a commercially available measuring device according to the method according to -B0601-1994.

As a method for obtaining a resin molded product from the above resin composition, general methods such as extrusion sheet molding using a T die, profile extrusion molding using an annular die, blow molding, injection molding, compression molding and the like can be mentioned. . In addition, the smooth, corrugated and prismatic sheets obtained by these methods are vacuum formed,
Secondary processing may be performed into an arbitrary shape by a method such as pressure molding or stampable molding.

Further, in the present invention, a resin molded body is formed by laminating a layer made of the above resin composition in a thickness of 5 to 200 μm on at least one surface of a base material made of a transparent resin. In this case, in addition to the effect that the antistatic property and the surface appearance are improved at the same time, when applied to the light source protective cover, the antistatic property can be imparted only to an arbitrary surface depending on the necessity. Is more preferable.

The thickness of the laminated portion is preferably in the range of 5 to 200 μm from the viewpoint that a sufficient antistatic property can be stably exhibited. The transparent resin used for the base material may be the same as or different from the transparent resin used in the resin composition, but preferably the same resin is used, more preferably methacrylic resin.

In order to obtain a resin molded product having a multilayer structure, a coextrusion molding method in which two or more kinds of resin compositions are simultaneously melted and extruded, and one of the two kinds of resin compositions is extruded in a single layer while the other is preformed. There are a method of laminating, a method of molding two kinds of resin compositions in advance and then thermocompression bonding by pressing, a method of continuously laminating and bonding, a method of vacuum forming, a method of laminating at the time of pressure forming.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to Examples and Comparative Examples. The evaluation and test methods used in each of the examples and comparative examples are as follows. (1) Measurement of number average molecular weight of polyether: The polyether was dissolved in chloroform, the molecular weight distribution was measured by a GPC method measuring machine (manufactured by Tosoh Corporation, liquid chromatograph 8010 series), and the number average molecular weight was calculated from the obtained distribution. Ask. (2) Measurement of carbon number average value of alkyl group of alkali metal salt of alkylsulfonic acid: mass spectrometer in which alkali metal salt of alkylbenzenesulfonic acid is dissolved in water and combined with FAB method (ionization method by fast atom collision) The mass spectrum is measured by JEOL Ltd., JMS-PX303 type), and the carbon number average value is determined from the carbon number distribution intensity of the obtained alkyl group.

(3) Measurement of weight average particle diameter of white inorganic compound particles: White fine particles are ultrasonically dispersed in an aqueous surfactant solution, and a centrifugal automatic particle size distribution measuring apparatus (Horiba Seisakusho, CAPA- 700) is used to measure the particle size distribution by a light transmission type sedimentation particle size distribution measuring method. From the obtained particle size distribution, a weight average particle size _Dd is determined. (4) Measurement of arithmetic average roughness ( _Ra ): JIS-B060
Surfcom 575A manufactured by Tokyo Seimitsu Co., Ltd. according to 1-1994
Using a mold surface roughness meter, the arithmetic mean roughness (R
_a ) is measured.

(5) Measurement of surface resistivity: JIS-K
Using a SM-8210 type ultra-ultra-insulator made by Toa Denpa Kogyo Co., Ltd. according to 6911, a value obtained by dividing the direct current voltage applied between the two electrodes on the surface of the test piece by the current flowing through the surface layer is taken as the surface specific resistance value. Measure. Test piece is 23 ℃, 50
It is measured after conditioning for 24 hours under the condition of% RH. When the measured value is less than 10 ¹³ Ω, it can be judged that the adhesion of dust and the like can be prevented and the antistatic property is sufficiently exhibited. (6) Installation evaluation in lighting equipment: A test piece is installed in front of an illumination light source equipped with two fluorescent tubes, and it is determined whether light scattering due to surface irregularities, minute patterns, foreign matters, aggregates, etc. are present. .
The judgment criteria are ○ if no abnormality can be confirmed, x if any abnormality is found, and the reason is entered.

[0038]

【Example】

Examples 1 to 6 and Comparative Examples 1 to 5 Methacrylic resin (trade name Del Powder 70H, manufactured by Asahi Kasei Corporation), polyethylene glycol having different molecular weights, and sodium alkylsulfonate having different carbon number distribution of alkyl groups, and weight average particle diameter Different calcium carbonate,
Barium sulfate was mixed according to the formulation shown in Table 1, blended with a Henschel mixer, and then an extruder with a vent 40 mmφ
The resin composition is pelletized at a resin temperature of 250 ° C. to obtain a raw material composition.

Table 1 shows the number average molecular weight of polyethylene glycol obtained by the above evaluations (1) to (3).
The carbon number average value of the alkyl group of sodium alkylsulfonate and the weight average particle diameter of the white inorganic compound particles are shown. The obtained pellets are extruded (screw diameter 50 mm
φ, L / D = 32, single axis), multi-manifold die,
Extrusion sheet molding is carried out using a unit consisting of three polishing rolls to prepare a single layer sheet having a width of 300 mm.

When a laminated sheet is produced, a second extruder (screw diameter 25 mmφ, L / D = 32, uniaxial) is combined to perform coextrusion sheet forming, and a width of 300 is similarly obtained.
A mm laminated sheet can be obtained. The thickness of the sheet is adjusted to a target of 2.0 mm by the clearance of the polishing roll. The thickness of the laminated portion of the laminated sheet is adjusted by the discharge amount balance of the two extruders. The obtained sheet is used as a test piece to evaluate the above (4) to (6), and the results shown in Table 2 are obtained.

In Examples 1 to 3, single-layer sheet test pieces were prepared by evaluating the same kind and addition amount of polyethylene glycol and sodium alkylsulfonate, and changing the kind and addition amount of calcium carbonate and barium sulfate. To do. In both cases, the arithmetic mean roughness is 1 μm or less, and the surface specific resistance value is on the order of 10 ¹² Ω, and both the surface appearance and the antistatic performance are preferable. Further, no abnormality is observed even when installed in a lighting device, which is very preferable as a member for a light source protection cover.

In Example 4, a single-layer sheet test piece is prepared by using sodium alkyl sulfonates having different carbon group average values of alkyl groups, and evaluation is carried out. The arithmetic average roughness is 1 μm or less, and the surface specific resistance value is on the order of 10 ¹¹ Ω, and both the surface appearance and the antistatic performance are preferable. Further, no abnormality is observed even when installed in a lighting device, which is very preferable as a member for a light source protection cover.

In Examples 5 to 6, laminated sheet test pieces were prepared by using raw material compositions in which the types and amounts of sodium alkylsulfonate, calcium carbonate and barium sulfate were the same and the number average molecular weight of polyethylene glycol was changed. Fabricate and evaluate. Arithmetic mean roughness is 0.5
The surface resistance and the antistatic performance are preferable because the surface resistance and the surface resistivity are in the order of 10 ¹¹ Ω. Moreover, no abnormality was found even when installed in a lighting device, and a very preferable result as a member for a light source protection cover was obtained.

In Comparative Example 1, a single-layer sheet test piece is prepared using polyethylene glycol having a number average molecular weight of 500 and evaluated. The arithmetic average roughness is as large as 1.5 μm, and the surface resistivity is also as high as 10 ¹⁴ Ω, and the surface appearance and antistatic performance are not sufficient, which is not preferable. Further, when it is installed in a lighting device, a lot of spotted patterns due to poor dispersion of the antistatic agent are confirmed, which is not preferable as a light source protection cover member.

In Comparative Example 2, talc having an average particle size of 15 μm is used as the inorganic compound particles, and a single-layer sheet test piece is prepared and evaluated. The arithmetic average roughness is as large as 5 μm, and the surface appearance is not preferable. Surface resistivity is 10 ¹³
Although it is on the order of Ω, it cannot be said that it exhibits sufficient antistatic performance. Further, when it is installed in a lighting device, light scattering due to surface irregularities becomes large, which is not preferable as a light source protection cover member.

In Comparative Example 3, a single-layer sheet test piece is prepared and evaluated using a raw material composition containing no inorganic compound particles. The arithmetic average roughness exceeds 1 μm, and the surface appearance is unfavorable. The surface resistivity is on the order of 10 ¹³ Ω, and the antistatic performance is not sufficient. Even when installed in a lighting device, the light source can be seen through and a spotted pattern on the surface due to aggregation of the antistatic agent is recognized, which is not preferable as a light source protection cover member.

In Comparative Example 4, a single-layer sheet test piece is prepared and evaluated using a raw material composition containing no sodium alkylsulfonate. The surface resistivity is as high as 10 ¹⁴ Ω and the arithmetic average roughness is more than 1 μm, which is not preferable in terms of antistatic performance and surface appearance. When it is installed in a lighting device, it has a low antistatic property and becomes dusty and dark, which is not preferable as a light source protection cover member.

In Comparative Example 5, a single-layer sheet test piece is prepared and evaluated using a raw material composition containing no polyethylene glycol. The arithmetic average roughness is 2 μm, and the surface specific resistance value is on the order of 10 ¹³ Ω, which is not preferable in both surface appearance and antistatic performance. Further, when it is installed in a lighting device, light scattering due to surface irregularities and a line pattern due to aggregation of the antistatic agent are confirmed, which is not preferable as a light source protection cover member.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

INDUSTRIAL APPLICABILITY The resin composition and the molded product obtained according to the present invention are excellent in antistatic property and surface appearance at the same time, and therefore, are extremely useful as a light source protection cover member for various lighting devices.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 71:02)

Claims (7)

[Claims] 1. (a) 100 parts by weight of a transparent resin, (b) a number average molecular weight represented by the following formula (1) is 2,000.
0.01 to 10 parts by weight of 0 to 50,000 polyether, (However, R ¹ is H or CH ₃ , and n is a constant determined by the average molecular weight.) (C) Alkyl having an average carbon number of the alkyl group represented by the following formula (2) within the range of 10 to 18 0.1 to 5 parts by weight of an alkali metal salt of sulfonic acid, (However, R ² is a C _{8 to} C ₁₈ straight-chain or branched alkyl group, and M is an alkali metal.) (D) At least one or more kinds having a weight average particle diameter of 0.1 to 20 μm. White inorganic compound particles 0.5 to 20
A resin composition comprising: by weight. 2. The resin composition according to claim 1, wherein the inorganic compound particles are calcium carbonate or barium sulfate. 3. The resin composition according to claim 1, wherein the transparent resin is a methacrylic resin. 4. A molded resin composition according to claim 1, wherein the arithmetic mean roughness (R _a ) of at least one surface is 1 μm or less. Resin molding. 5. A structure in which a layer made of the resin composition according to any one of claims 1 to 3 is laminated to a thickness of 5 to 200 μm on at least one surface of a base material made of a transparent resin. A resin molded body characterized by: 6. The resin molded product according to claim 4, wherein the inorganic compound particles are calcium carbonate or barium sulfate. 7. The resin molding according to claim 4, wherein the transparent resin is a methacrylic resin.