JP3193478B2 - Good transparency, antistatic synthetic resin molded product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin molded product having good transparency and antistatic properties.

[0002]

2. Description of the Related Art At present, many synthetic resin molded products are commercially available, but since they generally have a high electric resistance value, they are easily charged by friction and the like, and are attracted to dirt and dust to be stained or scratched. This causes problems such as sticking and the like, which impairs the appearance and in which a human may receive an electric shock when touching those charged devices.

In order to solve these problems, an antistatic property has been imparted to a synthetic resin molded article. The methods include (1) the internal addition of a surfactant, and (2) the addition of a surfactant. Surface coating (3) Surface coating of silicon-based compound (4) Surface modification by plasma treatment and the like. Among them, the method (3) has a short pot life of the coating solution, is expensive, and has a problem in the film performance itself. The method (4) has a non-permanent effect and is cost-effective. There are problems such as high cost, and the methods (1) and (2) are generally used.

In the method (1), a surfactant is mixed or dispersed in a synthetic resin raw material before polymerization or a synthetic resin before molding, so that the production process is simplified. In order to exhibit antistatic performance by using an agent, it is necessary to use a large amount of the agent, and there is a disadvantage that surface characteristics are deteriorated.
In addition, in the case of ionic surfactants, antistatic performance may be exhibited with a relatively small amount, but it does not dissolve uniformly and transparently, and causes phase separation over time even if temporarily dissolved,
Insolubles may be generated, and no suitable surfactant has been found.

[0005] The method (2) has the advantages that the physical properties of the synthetic resin molded article serving as the base material are not impaired, and that good antistatic performance can be obtained with a small amount of surfactant. However, on the other hand, there is a possibility that the original beautiful appearance of the synthetic resin molded product may be impaired, and the obtained antistatic performance is easily lost by washing or friction.

[0006] As described above, a synthetic resin molded article having excellent antistatic properties having excellent weather resistance, maintaining the original properties of a synthetic resin, and having excellent productivity in industrial production has not been obtained.

Furthermore, recently, in many cases, such as optical discs and video tapes, excellent surface hardness, transparency, and uniformity are required in addition to antistatic performance. At present it has not been obtained.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a synthetic resin molded article having excellent antistatic properties having excellent weather resistance and excellent transparency.

[0009]

According to the present invention, an ultraviolet ray mainly comprising the following (A) to (D) and containing 2.0 to 20% by weight of (A) on the surface of a molded article of a synthetic resin substrate. An object of the present invention is to provide an antistatic synthetic resin molded article having good transparency, wherein a cured product film of a curable resin composition is formed. (A) a monomer having a quaternary ammonium sulfonic acid group represented by the following general formula (a)

Embedded image [Wherein, R ₁ represents a hydrogen atom or a methyl group, X represents an oxygen atom or N (R ₃ ), Y represents an alkylene group or an oxyalkylene group, and R ₂ represents a saturated or unsaturated C 8-20 carbon atom. Shows an alkyl group. Here, R ₃ represents a hydrogen atom or a methyl group. (B) crosslinkable oligomer (C) trifunctional or higher polyfunctional acrylate and / or methacrylate (D) photopolymerization initiator

[0010] Of the above ultraviolet-curable resin compositions,
(A) is used for imparting antistatic properties to the molded article. The component (A) can provide an excellent antistatic performance of less than 10 ¹⁴ Ω / mouth by addition of a small amount. Further, the monomer constituting the component (A) has a good affinity with other ultraviolet-curable resin compositions, is stable with time in the composition, has very few agglomerates, and is transparent. A cured film can be obtained, and the acrylic group combines with the UV-curable resin to become a component of the cured film resin. The prevention performance is not lost by washing or friction, and a product having excellent durability and weather resistance can be obtained.

In the above general formula (A), the alkylene group or oxyalkylene group represented by Y preferably has 2 to 4 carbon atoms, and may be substituted with a lower alkyl group such as a methyl group or an ethyl group.

The alkyl group represented by R ₂ has 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms. When the number of carbon atoms is 7 or less, agglomerated foreign matters are apt to be mixed into the ultraviolet-curable resin composition, and the resulting cured product film is apt to smear, and the molded article has low antistatic performance. Also, when the number of carbon atoms exceeds 21, a large amount of agglomerated foreign matters is obtained, and only those having low antistatic performance can be obtained.

The alkyl group is preferably unsaturated from the viewpoint of aggregated foreign matter, but may be saturated. R
Examples of ₂ include an oleyl group, an octyl group, a dodecyl group, a hexadecyl group and the like, and among them, an oleyl group is preferred.

The sulfonic acid 4 represented by the above general formula (A)
The monomer having a quaternary ammonium salt group can be obtained by neutralizing an acrylic or methacrylic compound having a sulfonic acid group with a specific amine.

The acrylic or methacrylic compound having a sulfonic acid group includes sulfoalkyl such as 2-sulfoethyl acrylate, 3-sulfopropyl acrylate, 4-sulfobutyl acrylate and 2-sulfo-1,1-dimethyl-ethyl acrylate. Acrylate;
Sulfoalkyl methacrylates such as 2-sulfoethyl methacrylate, 3-sulfopropyl methacrylate, 4-sulfobutyl methacrylate, 2-sulfo-1,1-dimethyl-ethyl methacrylate; 2-sulfoethyl acrylamide, 3-sulfo Sulfoalkylacrylamides such as propylacrylamide, 4-sulfobutylacrylamide and 2-sulfo-1,1-dimethyl-ethylacrylamide; 2-sulfoethylmethacrylamide, 3-sulfopropylmethacrylamide, 4-sulfobutylmethacrylamide, 2- Sulfoalkyl methacrylamides such as sulfo-1,1-dimethyl-ethyl methacrylamide; sulfoalkoxyalkyl acrylates such as 2-sulfoethoxyethyl acrylate; Include a 2-sulfo-ethoxyethyl meth sulfoalkoxy alkyl methacrylic amides such as acrylamide; 2-sulfo alkoxyalkyl acrylamides such as ethoxyethyl acrylamide; sulfo alkoxyalkyl methacrylates such as sulfo ethoxyethyl methacrylate.

As the amine, a primary amine represented by R ₂ —NH ₂ is used, among which oleylamine,
Dodecylamine and tetradecylamine can be preferably cited in view of their antistatic ability and little aggregation foreign matter.

The neutralization reaction between the acrylic or methacrylic compound having a sulfonic acid group and the amine is carried out by dissolving both in a suitable solvent and mixing them. The solvent is not particularly limited as long as it dissolves a compound related to the reaction and does not react with itself. Alcohols such as alcohols and ethers are preferred, and lower aliphatic alcohols are particularly preferred. It is safe to carry out the reaction with cooling and stirring.

The mixing ratio of the two reaction components is preferably stoichiometrically 1: 1.

In the ultraviolet-curable resin composition of the present invention, the amount of the component (A) imparting antistatic properties is as follows.
0 to 20% by weight is preferable, and more preferably 2.0 to 20% by weight.
It is 15% by weight, particularly preferably 2.0 to 10% by weight. When the amount of the component (A) is less than 2.0% by weight, the surface resistance of the cured film becomes high and the antistatic ability becomes insufficient.
If it exceeds 0% by weight, the surface resistance of the cured film is satisfactory, but the compatibility with the component (B) is reduced, and the hardness, strength, wet heat resistance and adhesiveness of the film become insufficient.

The crosslinkable oligomer (B) used in the present invention has at least two ethylenically unsaturated bonds in the molecule,
For example, it refers to an addition-polymerizable compound having an acryloyl group. In the present invention, in the ultraviolet-curable resin composition,
The molecular weight per acryloyl group of the crosslinkable oligomer is preferably at least 150, more preferably 350 or more, and particularly preferably 1,000 or more.

When the molecular weight per acryloyl group is less than 150, the physical properties of the crosslinked film by irradiation with ultraviolet rays are small and small. As a result, when applied to an optical disk or the like, the adhesive strength to the recording film becomes weak, and furthermore, the decrease in a moist heat atmosphere is remarkably unsuitable for practical use. From the viewpoints of toughness (toughness) of the crosslinked film and volume shrinkage during curing, it is desirable that the molecular weight per crosslinkable acryloyl group be large. In order to minimize distortion of the medium (such as lifting of the recording film or warpage of the medium) on an optical disk or the like due to curing shrinkage due to ultraviolet irradiation, it is preferable that the molecular weight per acryloyl group of the crosslinkable oligomer is larger. However, since the viscosity of the system increases as the overall molecular weight increases, there are naturally limitations in terms of processing.

The following acrylates and / or methacrylates (hereinafter abbreviated as “(meth) acrylate”) are typical examples of the addition-polymerizable ethylenically unsaturated compound (B) which is a crosslinkable oligomer used in the present invention. Compounds in some cases).

Polyester (meth) acrylate, polyurethane (meth) acrylate, polyether (meth)
Examples include acrylate, epoxy (meth) acrylate, and silicone (meth) acrylate. The following can be further mentioned as specific examples of these.

That is, polybutylene adipate diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polyurethane diacrylate (composed of polyester glycol and isocyanate), spiro glycol urethane diacrylate, bisphenol A type epoxy acrylate, bisphenol F Epoxy methacrylate, phenol novolak epoxy acrylate, cresol novolac epoxy methacrylate, caprolactone-modified dipentaerythritol hexaacrylate,
And polydimethylcyclohexane dimethacrylate.

These acrylates are compounds having a high practical utility. In addition, unsaturated polyesters, DA
An acrylic resin such as a P resin, a vinyl resin such as a styrene copolymer, or a polyamide having an active group in a side chain;
Resins such as polyurethane, polyester, polysulfone, polyethersulfone and polyphenylene oxide modified with an acrylate ester can also be used as the crosslinkable oligomer (B). These may be used alone or in combination of two or more.

Typical examples of the (C) trifunctional or higher polyfunctional acrylate and / or methacrylate used in the present invention include the following.

That is, trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, tetramethylol methane tetra (meth) acrylate, dipentaerythritol hexaacrylate, triacryloyloxy isocyanurate, etc.

As the UV-curable resin composition, in addition to the above-mentioned components (A) to (C), bifunctional or monofunctional (meth) acrylates can be used in combination. Various (meth) acrylates can be selected from the viewpoint of appropriate physical properties.

For example, examples of the bifunctional (meth) acrylate include hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, and tricyclodecane dimethanol diacrylate.

Representative examples of monofunctional (meth) acrylates include 2-hydroxyethyl acrylate, lauryl methacrylate, diethylaminoethyl methacrylate, methyl methacrylate, n-butyl methacrylate, n-butyl acrylate, and tetrahydrofuran. Furyl acrylate can be mentioned.

In addition to the above (meth) acrylate, diallyl phthalate or styrene, vinyl acetate, acrylonitrile, vinyl chloride, or the like can be used.

In the present invention, (B) the crosslinkable oligomer is at least 15% by weight in the ultraviolet-curable resin composition.
It is preferable that the content be 2 or more.
5 to 50% by weight. When the content of the component (B) is less than 15% by weight, the obtained molded product has low strength and is brittle. On the other hand, if it exceeds 50% by weight, the viscosity of the resin composition becomes too high, making application difficult, and the solubility of the component (A) decreases.

The content of the (C) trifunctional or higher polyfunctional (meth) acrylate is preferably at least 20% by weight in the ultraviolet-curable resin composition. If the content of the component (C) is less than 20% by weight, the degree of crosslinking of the cured film is insufficient, and not only the initial physical properties such as the adhesive strength, but also the adhesive strength under a moist heat atmosphere are extremely impractical.
The content of the component (C) is more preferably 25% by weight or more, and particularly preferably 30 to 50% by weight.

In the UV-curable resin composition, (A)
+ (B) + (C) is preferably contained at least 80% by weight, more preferably at least 90% by weight.

The photopolymerization initiator (D) used in the present invention includes benzophenone initiators such as benzophenone and Michler's ketone, diketone initiators such as benzyl and phenylmethoxydiketone, acetophenone initiators such as acetophenone, and benzoin ethyl ether. Benzoin-based initiators such as benzyldimethyl ketal, 2,4
-Thioxanthone-based initiators such as diethylthioxanthone and quinone-based initiators such as 2-methylanthraquinone and camphorquinone are preferably used. These photopolymerization initiators may be used alone, or a plurality of compounds may be appropriately used in combination. If necessary, an accelerator such as an amine accelerator can be used in combination.

The upper limit of the amount of the photopolymerization initiator to be used is limited from a practical point of view such as cost, and is 1 to 10% by weight, preferably 2 to 10% by weight, based on the total amount of the ultraviolet curable resin.
~ 5% by weight is used.

In the present invention, there is no particular restriction on the base synthetic resin molded article. For example, PET (polyethylene terephthalate), PEN (polyethylene 2,6-naphthalate)
It can be easily applied to various synthetic resin films such as polyester films such as polyester films and polyolefin films such as polypropylene and polyethylene. further
The present invention can also be applied to audio tapes, video tapes, and the like, which are processed products of these molded products.

An optical disk, for example, a pit-type optical disk in which pits are formed on a substrate made of glass or resin such as a compact disk (CD), an optical disk in which a thermal recording layer is formed on a substrate, A bubble type optical disk in which bubbles are formed by irradiation with a laser beam or the like and a level change is detected by a change in reflected light, or a magneto-optical disk having a magneto-optical recording layer formed on a substrate is included. The optical disk to which the present invention is applied is an optical disk using a substrate made of a resin such as polycarbonate, polymethyl methacrylate, or amorphous polyolefin. Above all, the present invention is an optical disk that is required to have high hardness, transparency, etc., together with antistatic properties, a wide range of applications,
It is suitable for polyester films and the like that require similar performance for various uses.

In addition, the present invention can be easily used in the case of various OA equipments used in an environment where it is always easily charged.

In the present invention, the ultraviolet-curable resin composition can be applied to the surface of various molded products by a known coating method. For example, when applying to various optical disks, the disk surface can be coated by a spin coating method, an immersion coating method, a coating using a doctor knife, or a method using a bar coater. In particular, the spin coating method is the most practically preferable because the control of the film thickness is easy. When covering the optical disk, covering the side surfaces of the optical disk also improves the antistatic effect. In any case, the viscosity of the composition should be 20 poise or less, preferably 10 poise or less, more preferably 5 poise or less, in order to enable coating without using a solvent.
Less than poise. If it is more than that, it is not preferable because the coating film cannot be smoothly controlled.

Also, when applied to various films,
Coating methods such as a method generally used in web coating, a gravure roll coating, various roll coatings, an immersion coating method, and a bar coating are used depending on conditions.

Further, it is possible to easily obtain the molded product of the present invention by using an immersion coating method, a spray coating method and the like even for a three-dimensional molded product having a complicated form such as a housing of various OA equipment. it can.

In the molded article of the present invention, the thickness of the cured product film varies depending on the object, but is generally 0.01 to 100 μm.
, Preferably 0.5 to 50 µm, more preferably 1 to 20 µm. Below this, sufficient performance is not exhibited in terms of surface resistance, and above that, insufficient curing is apt to occur, and the coating performance becomes unstable, which is not preferable.

The molded article of the present invention has a surface resistance of 10 ¹⁴ Ω /
Preferably it is less than the mouth, more preferably 10 ¹³
Ω / mouth. Those having a surface resistance higher than this have no effect from the viewpoint of antistatic properties.

[0045]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to such an embodiment. In the examples, measurement of various characteristic values was performed according to the following.
Parts and percentages are by weight unless otherwise specified.

Surface resistance (Ω / port) : JIS K691
(1) Weather resistance test : Dipped in water at 70 ° C. for 16 to 24 hours, and then dried. Number of foreign substances in coating (number) : The number of particles having a diameter of 5 μm or more was counted in one visual field with a 200 × optical microscope. Surface hardness : JIS K5400 (paint general test method)
Pencil scratch test. Adhesive strength : Cross batch adhesion test in JIS K5400. That is, 11 cuts were made in the coating at 1 mm intervals so as to be orthogonal,
00 independent square portions were formed, and the pieces were peeled off three times with an adhesive tape (Cellotape (registered trademark) manufactured by Nichiban Co., Ltd.), and the number of remaining square portions was determined. Filtration property of ultraviolet-curable resin composition: The amount of filtration (l) of the ultraviolet-curable resin composition which causes clogging of the filter by applying a pressure of 0.5 kg with a 0.5 μm filter was measured.

Reference Example 1 In a glass flask with stirring blades, 2-sulfo-1,
1-dimethyl-ethylacrylamide (hereinafter referred to as “TBA
270 parts of oleylamine was dissolved in 600 parts of 20% aqueous methanol.
Dissolved in 100 parts of water-containing methanol at an internal temperature of 30%.
The solution was added dropwise at a temperature of not more than ℃ and stirred for 1 hour to obtain a quaternary ammonium sulfonic acid salt. This one is TBAS
Abbreviated as -OL.

Reference Examples 2 to 18 The amines shown in Table 1 were used in place of oleylamine, and 2-sulfo-1,1-dimethyl-ethylmethacrylamide (TBMS) and 2-sulfoethyl acrylate (TBMS) were used in place of TBAS. SEA) or 2-sulfoethyl methacrylate (SEM) was used to produce the quaternary ammonium sulfonic acid salt shown in Table 1 in the same manner as in Reference Example 1.

[0049]

[Table 1]

Examples 1 to 6 The TBAS-OL obtained in Reference Example 1 and the crosslinkable oligomer were placed on the flat (non-groove formed) surface of a polycarbonate resin optical disc substrate having a thickness of 1.2 mm and a diameter of 90 mm. And Table 2 containing polyfunctional (meth) acrylate and the like
The ultraviolet-curable resin composition having the described composition was uniformly applied to a thickness of about 5.0 μm by a spin coater.

Next, ultraviolet rays were irradiated from the side of the applied ultraviolet-curable resin composition layer by a high-pressure mercury lamp of 80 W / cm to cure the resin. In addition, as for all the photopolymerization initiators, Darocure 1173 (manufactured by Ciba-Geigy) is used in 3p.
hr (parts per hundred resin) was added.

The surface resistance of the obtained disk was measured.
Next, the surface resistance of each disk after the weather resistance test was measured. Table 3 shows the results. As shown in Table 3, it can be seen that the surface resistance value did not substantially change even after the severe weather test.

Comparative Examples 1 to 5 The same optical disk substrate as in Example 1 was used, and the flat surface of the substrate was cured in the same manner as in Example 1 using an ultraviolet-curable resin composition having the composition shown in Table 2. A coating was formed and evaluated. Table 3 shows the results.

Comparative Example 6 A commercially available antistatic agent "HIBOLON SCI" (manufactured by Boron International) was applied to the same optical disk substrate as in Example 1.
Was applied and heat-treated at 80 ° C. for 10 minutes to form a cured film, which was evaluated in the same manner as in Example 1. Table 3 shows the results. Table 3 shows that the cured film has low antistatic performance after the weather resistance test.

[0055]

[Table 2]

In Table 1, the abbreviations of the compound names are as follows. BPA-EA: bisphenol A-epoxy acrylate PN-EPA: phenol novolak-epoxy acrylate CSN-EPA: cresol novolak-epoxy acrylate TMPTA: trimethylol propylene triacrylate NPGDA: neopentyl glycol diacrylate HDDA: hexanediol diacrylate DEG-DA : Diethylene glycol diacrylate THF-A: tetrahydrofurfuryl acrylate PETA: pentaerythritol tetraacrylate

[0057]

[Table 3]

Examples 7 to 9 A 100 μm-thick polyester film was coated with a UV-curable resin composition having the composition shown in Table 4 using a bar coater, and then UV-irradiated using an 80 W / cm high-pressure mercury lamp. Was. The surface resistance of the cured film-formed surface of the obtained film was measured, and then the surface resistance after the weather resistance test was measured. Even after such a severe test, it was confirmed that the surface resistance value did not substantially change. Table 5 shows the results.

Comparative Examples 7 to 9 A cured film was formed on the same film as used in Example 7 by using the ultraviolet-curable resin composition having the composition shown in Table 4 in the same manner as in Example 7, and the surface resistance was measured. It measured and evaluated similarly. Table 5 shows the results.

[0060]

[Table 4]

[0061]

[Table 5]

Examples 10 to 11 and Comparative Examples 10 to 13 A quaternary ammonium sulfonic acid salt, a crosslinkable oligomer and a polyfunctional compound shown in Table 6 were placed on a flat surface of a polycarbonate optical disk substrate having a thickness of 1.2 mm and a diameter of 90 mm. A UV-curable resin composition comprising acrylates and other acrylates was uniformly applied with a spin coater to a thickness of about 5 μm. Then, after treating in the same manner as in Example 1, evaluation was made. Table 7 shows the results.

[0063]

[Table 6]

[0064]

[Table 7]

Examples 12 to 15 In Example 2, only the type of the quaternary ammonium sulfonic acid salt was changed as shown in Table 8 and evaluated. Table 8 shows the results.

[0066]

[Table 8]

[0067]

According to the present invention, it is possible to provide a synthetic resin molded article having excellent antistatic properties having excellent weather resistance and excellent transparency.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08J ^7/ 04-7/06 B32B 27/00-27/42

Claims (6)

(57) [Claims] The present invention mainly comprises the following (A) to (D) on the surface of a molded article of a base synthetic resin, wherein (A) is 2.0 to 2
A molded article of an antistatic synthetic resin having good transparency, wherein a cured film of an ultraviolet curable resin composition containing 0% by weight is formed. (A) a monomer having a quaternary ammonium sulfonic acid represented by the following general formula (a): [Wherein, R ₁ represents a hydrogen atom or a methyl group, X represents an oxygen atom or N (R ₃ ), Y represents an alkylene group or an oxyalkylene group, and R ₂ represents a saturated or unsaturated C 8-20 carbon atom. Shows an alkyl group. Here, R ₃ represents a hydrogen atom or a methyl group. (B) crosslinkable oligomer (C) trifunctional or higher polyfunctional acrylate and / or methacrylate (D) photopolymerization initiator 2. The crosslinkable oligomer is an addition-polymerizable compound having at least one acryloyl group in a molecule, and has a molecular weight of at least 15 per acryloyl group.
2. The molded article of the antistatic synthetic resin having good transparency according to claim 1, which is 0. 3. The antistatic property with good transparency according to claim 1, wherein the ultraviolet-curable resin composition contains (B) at least 15% by weight thereof and (C) at least 20% by weight. Synthetic resin molded product. 4. The molded article of an antistatic synthetic resin having good transparency according to claim 1, wherein the surface resistance of the cured product film is less than 10 ¹⁴ Ω / port. 5. The transparent article according to claim 1, wherein the molded article of the base synthetic resin is an optical disk made of a transparent synthetic resin substrate, and the cured material film is formed on a reading surface thereof. Antistatic synthetic resin molded product. 6. The molded article of the antistatic synthetic resin with good transparency according to any one of claims 1 to 4 , wherein the molded article of the base synthetic resin is a polyester film.