JP3068284B2 - 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 article having good and permanent 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, dust and the like to be stained and damaged. This causes problems such as impairing the appearance such as sticking, and the possibility of receiving an electric shock when a person touches these charged devices.

Methods for imparting antistatic properties to synthetic resin molded articles include (1) internal addition of a surfactant, (2) surface coating of a surfactant, (3) surface coating of a silicon compound, and (4) plasma treatment. And the like by surface modification. Among these methods, 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 permanent effect and is costly. In general, the methods (1) and (2) are used.

[0004]

The method of internally adding a surfactant involves mixing or dispersing the surfactant into a synthetic resin raw material before polymerization or a synthetic resin before molding, so that the manufacturing process is simplified. In order to obtain sufficient antistatic performance, it is generally necessary to increase the amount of the surfactant to be added, and it is difficult to maintain the original physical properties of the synthetic resin molded product. In addition, these surfactants are liable to move inside the molded article, so that the obtained antistatic properties are easily lost due to washing with water, friction and the like, and there is a disadvantage that the durability is poor.

[0005] Further, a method of applying a surfactant on the surface is as follows.
It does not impair the physical properties of the synthetic resin used as the base material, and has the advantage that good antistatic performance can be obtained with a small amount of surfactant, but it may impair the beautiful appearance of the synthetic resin molded product. Further, there is a disadvantage that the obtained antistatic performance is easily lost due to washing with water, friction and the like.

As described above, there has been no synthetic resin molded article which exhibits good antistatic performance permanently and retains the original physical properties of the synthetic resin.

Furthermore, recently, in many cases, such as optical disks and video tapes, in addition to antistatic performance, excellent surface hardness, moisture resistance and light transmission are required, and these performances are satisfied. Things have not been obtained.

[0008]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies in view of the above-mentioned problems, and as a result, have found that a specific ultraviolet curable resin containing a monomer having a quaternary ammonium salt having a specific structure. It has been found that by coating the surface of a synthetic resin molded article with the above, permanent antistatic performance can be imparted without impairing the physical properties inherent in the synthetic resin molded article, and arrived at the present invention.

That is, according to the present invention, (A) the following general formula (A)

[0010]

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[0011] [wherein, R ¹ represents a hydrogen atom or a methyl group, R ^3, and R ^4, R ⁵ each independently represent a hydrogen atom or an alkyl group, R ² is an alkylene group or an oxyalkylene group, X ^- is halogen _{^{ions, R 6 SO 3 - (R}} 6 is an alkyl group substituted aromatic group, alkoxy group) or (R
⁷ 0) ₂ P0 ₂ ^- (a monomer having a quaternary ammonium salt R ⁷ is represented by an alkyl group)], (B) and the crosslinkable oligomer, the (C) 3-functional or higher-functional acrylic Acid esters and / or methacrylic esters;
(D) An antistatic synthetic resin molded article characterized by forming a cured film of an ultraviolet curable resin composition mainly comprising a photopolymerization initiator.

[0012] Among them, an antistatic synthetic resin molded article in which the crosslinkable oligomer forms a cured film of an ultraviolet curable resin composition having a molecular weight per acryloyl group of at least 150, and further, the content of the crosslinkable oligomer is Fifteen
wt% or more, and the content of trifunctional or more polyfunctional acrylate and / or methacrylate is 20
An antistatic synthetic resin molded article formed by forming a cured product film of an ultraviolet curable resin composition having a content of the monomer having a quaternary ammonium salt of 10 to 50% by weight or more is preferable.

The monomer having a quaternary ammonium salt used as a monomer of the ultraviolet-curable resin composition in the present invention is represented by the general formula (A), and quaternizes an acrylate or methacrylate having an amino group. It can be obtained by: Examples of the acrylate or methacrylate having an amino group include dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, diethylaminoethylpropyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, diethylaminoethyl propyl acrylate,
Examples thereof include dihydroxyethylaminoethyl methacrylate and the like, and mixtures thereof.

Examples of the quaternizing agent include alkyl sulfates such as dimethyl sulfate, diethyl sulfate, dipropyl sulfate and the like;
Sulfonates such as methyl P-toluenesulfonate, methyl benzenesulfonate, methyl methanesulfonate and methyl trifluoromethanesulfonate; alkyl phosphoric acids such as trimethyl phosphate and triethyl phosphate; halides such as alkyl benzyl chloride and benzyl chloride. And alkylsulfuric esters and sulfonic esters are particularly preferred from the viewpoint of thermal decomposition resistance.

The quaternization reaction is carried out by dissolving both in an appropriate solvent and mixing them. The solvent is not particularly limited as long as it is a substance that dissolves a compound related to the reaction and does not react. 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 such that the amino group-containing (meth) acrylic acid ester compound is used in an excess state. When the sulfate ester and the like are in an excessive state, an unreacted quaternizing agent is present. And the hydrolyzate of these quaternizing agents may degrade the periphery of the coating, which may lead to generally undesirable results. Conversely, the amino group-containing (meth) acrylate compound is used as a surface modifier, so long as the surface resistance value is within a desired range, excess amino group-containing (meth) acrylate compound can be used. Even if present, there is generally no particular problem.
In the quaternization, the mixing ratio of the amino group-containing (meth) acrylates exceeds 100 mol% with respect to the quaternizing agent such as a sulfate ester or a sulfonate ester.
It is at most 00 mol%, preferably from 110 to 500 mol%, more preferably from 120 to 400 mol%. When the amount of the amino group-containing (meth) acrylic acid ester exceeds 600 mol%, the reaction rate tends to decrease.
If the content is 0 mol% or less, the possibility of the presence of unreacted sulfate ester or sulfonate ester increases as described above, which is not preferable.

In this reaction, an acrylate having an amino group or the like and a quaternizing agent may be mixed in advance as described above, but after mixing with other components of the present invention, the quaternizing agent is added. However, there is no problem as long as unnecessary side reactions do not progress. In order to increase the solubility of a quaternary compound such as an acrylate having an amino group, the addition of a small amount of alcohol may be used within a range that does not seriously affect the performance of the film.

The crosslinkable oligomer used in the present invention has at least one ethylenically unsaturated bond in the molecule, for example,
An addition-polymerizable compound having an acryloyl group.

In the present invention, in the ultraviolet curable resin,
The molecular weight per acryloyl group of the crosslinkable oligomer is at least 150, preferably 350 or more, and particularly preferably 1,000 or more.

Here, the molecular weight per acryloyl group is 1
If it is less than 50, the properties of the crosslinked film by ultraviolet irradiation are small and small. As a result, when applied to a glowing disc, etc., the adhesive strength with the recording film becomes weak,
Furthermore, the decrease in a moist heat atmosphere is remarkable, and it is not suitable 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 the medium distortion (lifting of the recording film, warpage of the medium, etc.) in a light disk or the like due to curing shrinkage due to ultraviolet irradiation, it can be said that the molecular weight per acryloyl group of the crosslinkable oligomer is preferably 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) acrylates") are typical of addition-polymerizable ethylenically unsaturated compounds which are crosslinkable oligomers used in the present invention. ) Compounds can be exemplified.

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

Polybutylene adipate diacrylate,
Polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polyurethane diacrylate (composed of polyester glycol and isocyanate), spiroglycol urethane diacrylate, bisphenol A type epoxy acrylate, bisphenol F type epoxy methacrylate, phenol novolak type epoxy acrylate, Cresol novolak type epoxy methacrylate, caprolactone-modified dipentaerythritol hexaacrylate, polydimethylsiloxane dimethacrylate and the like.

These acrylates are practically useful compounds. In addition to these, unsaturated polyesters, allyl resins such as DAP resins, vinyl resins such as styrene copolymers, or polyamides having an active group in the side chain ,
Resins such as polyurethane, polyester, polysulfone, polyethersulfone, polyphenylene oxide and the like modified with an acrylate ester can also be used sufficiently.

In the present invention, the crosslinkable oligomer comprising the addition-polymerizable ethylenically unsaturated compound is used in an amount of at least 15 wt%, preferably 25 wt% or more, and may be used alone or in combination of two or more. Is also good.

The amount of the monomer component having a quaternary ammonium salt imparting antistatic properties of the present invention is 10 to 50 wt.
%, Preferably 15 to 45 wt%, more preferably 20%
４０40 wt%. When the content is 10 wt% or less, the resistance becomes high and the antistatic ability is insufficient. When the content is 50 wt% or more, the surface resistance of the cured film is satisfactory, but the compatibility with the crosslinkable oligomer or the like is reduced, The hardness, strength, and surface properties of the rubber composition become insufficient, and it becomes difficult to satisfy the characteristics of the present invention.

The content of the trifunctional or higher polyfunctional (meth) acrylate used in the present invention is at least 20% by weight. Preferably it is 25% by weight, particularly preferably 30% by weight or more. Trifunctional or higher polyfunctional (meta)
When the content of the acrylate is less than 20% by weight, the degree of crosslinking of the film cured by ultraviolet rays 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 remarkably impractical.

The following are typical examples of the trifunctional or higher polyfunctional (meth) acrylate used in the present invention.

Trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, dipentaerythritol hexaacrylate,
Triacryloyloxy isocyanurate and the like.

In addition to the above-mentioned trifunctional or higher polyfunctional (meth) acrylate, bifunctional or monofunctional (meth) acrylate can be used in combination with the ultraviolet curable resin actually used. Various (meth) acrylates can be selected from the viewpoint of optimizing the physical properties after curing.

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

The following are typical examples of monofunctional (meth) acrylates.

Examples include 2-hydroxyethyl acrylate, lauryl methacrylate, diethylaminoethyl methacrylate, methyl methacrylate, n-butyl methacrylate, n-butyl acrylate and tetrahydrofurfuryl acrylate.

In addition to the above (meth) acrylate,
It is also possible to use diallyl phthalate, styrene, vinyl acetate, acrylonitrile, vinyl chloride and the like.

As the photopolymerization initiator, benzophenone,
Benzophenone initiators such as Michler's ketone; diketone initiators such as benzyl and phenylmethoxydiketone; acetophenone initiators such as acetophenone; benzoin initiators such as benzoin ethyl ether and benzyl dimethyl ketal; and 2,4-diethylthioxanthone Thioxanthone initiators, quinone initiators such as 2-methylanthraquinone and camphorquinone are preferably used. If necessary, an accelerator such as an amine accelerator may be used in combination. The upper limit of the amount of the initiator to be used is limited from a practical point of view such as cost, and 1 to 10% by weight, preferably 2 to 5% by weight based on the total amount of the curable resin composition is used.

These initiators may be used alone or in combination of two or more compounds.

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

An optical disk, for example, a pit-type optical disk having pits formed on a substrate made of glass or resin such as a compact disk (CD), an optical disk having a thermal recording layer formed on the substrate, a laser beam For example, a bubble-type optical disk in which a bubble is formed by irradiation of light and the 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. An optical disk to which the present invention is applied is an optical disk using a resin substrate such as polycarbonate, polymethyl methacrylate, or amorphous polyolefin for the substrate. In particular, the present invention is suitable for optical discs that require high hardness and transparency, as well as antistatic properties, and polyester films that are widely used and require similar performance in various applications.

In addition, the present invention can be easily used in the case of various OA equipment used in an environment where charging is always easy.

The antistatic composition of the present invention 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 spin coating, dip coating, coating with a doctor knife, or with 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 surface of the optical disk also improves the antistatic effect. In any case, the viscosity of the antistatic composition is 20 poises or less, preferably 10 poises or less, more preferably 5 poises or less, in order to enable coating without using a solvent. If it is more than that, it is not preferable because the coating film cannot be smoothly controlled.

In the case of coating on various films, the method widely used in web coating, gravure roll coating, various roll coating, dip coating, bar coating and the like may be applied according to the conditions. used.

Further, the present invention can be easily applied to a three-dimensional molded article having a complicated form such as a housing of various OA equipments by using a dip coating method, a spray coating method or the like.

Although the thickness of the coating film of the present invention varies depending on the object, it is generally from 0.01 to 100 μm, preferably from 0.5 to 50 μm, more preferably from 1 to 20 μm. Below this, sufficient performance cannot be exhibited in terms of surface resistance, and above that, insufficient curing is apt to occur, and the coating film performance becomes unstable, which is not preferable.

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

[0045]

The present invention will be described in more detail with reference to the following examples. The present invention is not limited to such an embodiment.

First, a mixture of 112.2 parts (parts by weight, the same applies hereinafter) of diethylaminoethyl methacrylate and 220 parts of ethanol were put into a glass flask equipped with stirring blades, and a mixture of 77 parts of diethyl sulfuric acid and 77 parts of ethanol was stirred. The mixture was added dropwise at an internal temperature of 30 ° C. or lower, and stirring was continued for 1 hour after the completion of the addition to obtain a mixture of diethylaminoethyl methacrylate having a quaternary ammonium salt. This is abbreviated as “DEAMS” below.

[0047]

Examples 1-4 A polycarbonate resin optical disc substrate having a thickness of 1.2 mm and a diameter of 130 mm has a flat (non-groove) surface containing the DEAMS, a crosslinkable oligomer, a polyfunctional acrylate and the like. An ultraviolet-curable resin composition having the composition shown in Table 1 was uniformly applied to a thickness of about 10 μm by a spin coater.

Next, from the side of the applied organic material layer, 80 W /
The resin was cured by irradiating ultraviolet rays with a high-pressure mercury lamp of cm.

The photopolymerization initiator used was Darocur 1173 (Ciba Geigy) at 3 phr (parts per part).
hundred resin).

The surface resistance of the obtained disks was measured, and then each disk was immersed in water at 70 ° C. for 16 to 24 hours, dried, and the surface resistance was measured again. Even after such a severe test, it was confirmed that the surface resistance value did not substantially change. The results are summarized in Table 2. In the examples, the surface resistance (Ω / □) was based on JIS K6911.

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

[0052]

Comparative Examples 1 to 4 The same substrates as in Examples 1 to 4 were used, and an ultraviolet curable resin composition having a composition outside the scope of the present invention described in the section of Comparative Examples in Table 1 was used. In the same manner, a cured film was formed on the flat surface of the substrate and evaluated. The results are also shown in Table 2. When the amount of DEAMS is out of the range, it is found that there are disadvantages such as an excessively high surface resistance or insufficient hardness.

[0053]

Comparative Example 5 A commercially available antistatic agent "HIBOLON SCI" (Boron International) was applied to the same disk substrate as in Examples 1 to 4, and a heat treatment was performed at 80 DEG C. for 10 minutes to form a cured film. In the same manner as in the above, surface resistance values before and after the acceleration test were measured and evaluated. The results are shown in Table 2. As a result, it is understood that the durability of the antistatic effect of the cured film is low unlike the above-described embodiment.

[0054]

[Table 1]

[0055]

[Table 2]

[0056]

Examples 5 to 7 A 100 μm-thick polyester film was coated with a UV-curable resin composition having the composition shown in Table 3 by means of a bar coater, and subsequently irradiated with UV rays using a high-pressure mercury lamp of 80 w / cm. . The surface resistance of the cured film-formed surface of the obtained film was measured, and then each film was immersed in 70 ° C. water for 16 to 24 hours, dried, and the surface resistance was measured again. Even after such a harsh test,
It was confirmed that the surface resistance did not substantially change. The results are summarized in Table 4.

The abbreviations of the compound names in Table 3 are the same as in Table 1.

[0058]

Comparative Examples 6 to 10 The same films as in Examples 5 to 7 were used.
Using the ultraviolet-curable resin composition having the composition described, a cured film was formed in the same manner as in the example, and the surface resistance was measured and evaluated in the same manner as in the example. Table 4 shows the results.

[0059]

[Table 3]

[0060]

[Table 4]

[0061]

Examples 8 to 10 Using the same substrate as in Examples 1 to 4, the ultraviolet curable resin composition of Example 1 was changed to the DEAMS of Example 1 except for the quaternizing agent alone. Using the curable resin composition, a cured film was formed in the same manner as in Example 1, and evaluated by the surface resistance. Table 5 shows the results.

[0062]

[Table 5]

[0063]

The present invention is to provide a synthetic resin molded article having a high durability and having an antistatic property, and in particular, a synthetic resin molded article such as an optical disk which requires a transparent and high hardness surface. It is suitable for.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C09D 133/14 C09D 133/14 (56) References JP-A-60-221414 (JP, A) JP-A-62-207353 (JP) JP-A-60-248745 (JP, A) JP-A-54-93025 (JP, A) (58) Fields studied (Int. Cl. ⁷ , DB name) C08J ^7/ 00-7/18 B32B 27/00-27/42 C09D 5 / 00,133 / 14

Claims (6)

(57) [Claims] 1. A surface of a molded article of a synthetic resin substrate (A) having the following general formula (a): [Wherein, R ¹ represents a hydrogen atom or a methyl group, R ³ ,
R ⁴ and R ⁵ each independently represent a hydrogen atom or an alkyl group;
R ² is an alkylene group or an oxyalkylene group, X ^-
Halogen ions, R ⁶ SO ₃ is ^- (R ⁶ is an alkyl group substituted aromatic group, an alkoxy group) or (R ⁷ 0) ₂ P0 ₂
^- (R ⁷ is an alkyl group) and a monomer having a quaternary ammonium salt represented by showing a], (B) and the crosslinkable oligomer, (C) 3 acrylate functional or higher polyfunctional and /
Alternatively, an antistatic synthetic resin molded article formed by forming a cured film of an ultraviolet curable resin composition mainly comprising a methacrylate ester and (D) a 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 1 per acryloyl group.
The antistatic synthetic resin molded product according to claim 1, wherein the number is 50. 3. The ultraviolet-curable resin composition has a crosslinkable oligomer content of 15% by weight or more, and a polyfunctional acrylate and / or methacrylate ester content of 20% by weight or more. And the content of the monomer having a quaternary ammonium salt is 10 to 50% by weight.
The antistatic synthetic resin molded product according to claim 1 or 2, which is: 4. The cured product film has a surface resistance of 10 ¹⁴ Ω.
4. The antistatic synthetic resin molded product according to any one of claims 1 to 3, wherein the ratio is less than //. 5. The antistatic property according to any one of claims 1 to 4, wherein the base synthetic resin molded product is an optical disk made of a transparent synthetic resin substrate, and the cured material film is formed on a reading surface thereof. Synthetic resin molded product. 6. An antistatic synthetic resin molded article according to any one of claims 1 to 4, wherein the base synthetic resin molded article is a polyester film.