JPS5980403A - Ultraviolet-curing antistatic composition - Google Patents

Abstract

PURPOSE:To provide the titled composition composed of an ultraviolet curing prepolymer, a specific reactive monomer, and a photopolymerization initiator, and giving a coating film having excellent antistatic property and abrasion resistance when applied to the surface of a molded resin article and cured by ultraviolet radiation. CONSTITUTION:The objective composition is prepared by compounding (A) a prepolymer curable by ultraviolet irradiation in the presence of a photopolymerization initiator [e.g. a urethane (meth)acrylate obtained by the reaction of a polyvalent isocyanate with a polyfunctional (meth)acrylate of formula (n is 1-4; R is H or methyl)], (B) a compound having one or more hydroxyl groups and one or more halogen atoms in a molecule (e.g. 3-chloro-2-hydroxypropyl methacrylate) and (C) a photopolymerization initiator capable of absorbing ultraviolet radiation (preferably benzyle ketal), preferably at weight ratios of (50-70):(50- 30):(1-2). EFFECT:The composition gives a coating film having excellent water resistance, heat resistance, abrasion resistance and strength, without degrading the appearance and color of the molded article.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultraviolet curable antistatic composition.

Products made using natural or synthetic polymers are generally not conductive, and static electricity accumulates on them.

This electrical charge attracts fine dust to the surface of products using polymers, causing stains and scratches on the products.

Furthermore, when the charging potential increases, electrostatic discharge occurs, which may be one of the causes of explosions of powder, granules, and combustible gas. Furthermore, when polymer products are used as electronic components, a phenomenon is observed in which charging causes electrical circuits to malfunction. For these reasons, antistatic treatment of polymer products is strongly desired.In response to this demand, various methods of antistatic treatment have been proposed. For example, (1) forming a thin film containing a surfactant on a synthetic resin molded article;

There are methods such as ■mixing and dispersing a surfactant into a synthetic resin molded product, ■mixing and dispersing a conductive metal powder into a synthetic resin, and ■mixing and dispersing carbon black into a synthetic resin. There are many points that need to be improved, such as the transparency, heat resistance, and mechanical strength of synthetic resins being reduced due to mixing and dispersion of additives. An object of the present invention is to provide a composition that can easily form a coating with excellent performance.

That is, the present invention provides a prepolymer [A] that is cured by ultraviolet irradiation in the presence of a photopolymerization initiator, which has at least 7 hydroxyl groups, at least 7 unsaturated groups, and at least 7 halogen atoms in the molecule. Compound [B] having at the same time
, a photopolymerization initiator [C] that absorbs light in the ultraviolet region.

The above three components [A], [B], and [C] are stirred and mixed at room temperature or heated, and this composition is polymerized and cured by irradiating it with ultraviolet ls. For example, immersing a resin molded article in this composition solution,
Alternatively, if a coating film is formed by spraying and irradiated with ultraviolet rays, a film with excellent antistatic performance and scratch resistance can be obtained.

As the prepolymer of component [A], any ultraviolet curable prepolymer can be used, and in the composition of the present invention, a cured film with excellent mechanical strength and scratch resistance can be obtained by curing by ultraviolet irradiation. However, when combined with polyvalent isocyanates such as tolylene diisocyanate, diphenylmethane-p, p'-diisocyanate-11 hexamethylene diisocyanate trimer (for example, Duranate ■ manufactured by Asahi Kasei Corporation), Urethane (meth)acrylate prepolymer obtained by reacting with a polyfunctional (meth)acrylate represented by general formula (1), (HOCH2kc+cHz o8 C(R)=CH
z), ・Bend/Tune (1) (n-heko 1.7.4 (, R
: Hydrogen atom or methyl group) Reaction product of 7-talic acid and trimethylolpropane diacrylate, such as Aronix @ gobo (manufactured by Toagosei ■) Ester acrylate prepolymer, epoxy acrylate prepolymer, such as Kyoeisha Yushi, yoo, 2P, Shin Nakamura Chemical ABPE-?
Examples include Showa Kobunshi 5PIkOA-. 3002A,
ABPE-Q,SP/! ;The chemical structural formula of OAX is as follows.

π CH,=CH-coo-CH2-cHt)t -0AB
PE-da H8C-C-CH
.

■ Among the above, the urethane acrylate prepolymer obtained by the reaction of duranate ■ and pentaerythritol triacrylate is the most preferred, followed by the one obtained by the reaction of duranate ■ and dipentaerythritol hexaacrylate, and toluylene diisocyanate prepolymer. Urethane acrylate prepolymer 5-mer obtained by reaction with pentaerythritol triacrylate, then urethane acrylate obtained by reaction of diphenylmethane-p, p'-diisocyanate with pentaerythritol triacrylate, supra)
002A, ABPE - an epoxy acrylate prepolymer.

As the reactive monomer of component [B], those having at least seven hydroxyl groups, unsaturated groups, and halogen atoms in the molecule are used, and the antistatic performance is provided by this component CB).

Specific examples thereof include 3-chloro-hydroxyprobyl (meth)acrylate, 3-promo-hydroxyprobyl (meth)acrylate, 3-chloro-hydroxyprobyl-2-[(2-methyl-7- Oxycopropenyl)oxy]ethyl ester, etc. As the unsaturated group of these reactive monomers, an acryloyloxy group is preferable to a methacryloyloxy group because it has a faster ultraviolet curing speed.

Further, in order to impart hardness and scratch resistance to the polymerized and cured coating, the following crosslinking monomers may be added as necessary. 7. Compounds having (meth)acryloyl groups such as 6-hexanediol diacrylate, ethylene glycol diacrylate, polyethylene glyfur diacrylate, neopentyl glycol diacrylate, butanediol diacrylate, and the amount added is 3 ~73 parts by weight is preferred.

Examples of the photopolymerization initiator of component [C] include benzyl, benzoin, benzophenone, acetophenone, anthraquinone, benzyl ketal, xanthone, thioxanthone, and derivatives thereof, such as /-chloroanthraquinone, coethylanthraquinone, cochlorothioxanthone. , Michler's ketone, benzoin ethyl ether, coumethoxybenzophenone, S-chloro-hydroxypenzophenone, jetoxyacetophenone, p-chlorobenzophenone, p-t-butyltrichloroacetophenone, etc.0 Among these, benzoin and benzyl ketal are This is preferable from the viewpoint of achieving higher antistatic performance. When using a photopolymerization initiator other than the above, such as benzophenone, anthraquinone, or xanthone, a mixture of three components [A], [B], and [C] is used as a go-go.
If it is applied after heating to "C" and polymerized and cured by irradiation with ultraviolet rays, it can exhibit antistatic properties similar to those obtained by curing at room temperature using benzoin or benzyl ketal.

The preferred mixing ratio of the three components (Al, CB) and [C] is:
[A] component SO to 70% by weight, CB) component 50 to 30% by weight, [C] acid component [A], CB) in a total amount of 7 to 2 parts by weight based on a total of 10[theta] parts by weight. With this ratio, a cured film with excellent antistatic performance and scratch resistance can be obtained.

[B] Acid component This is a component that imparts antistatic performance. When this ratio decreases, antistatic performance 2 decreases to 30% by weight.
In this case, the half-life showing antistatic performance is 20 to 50 seconds, making it impractical. [B] As the acid component ratio increases, the antistatic performance increases, and when it reaches 90% by weight, the half-life becomes 1 to 2 J seconds. However, since this means a decrease in the CA] component ratio, the scratch resistance decreases. For example, the scratch resistance of the coating will be approximately the same as that of polymethyl methacrylate sheet. That is, taper abrasion resistance (C8l
oF 5oof load, haze% after /θO rotation) is approximately 3
It is around 5%. [A] The taper abrasion resistance increases as the component ratio increases, and CA]:CB'3=so:5o-c has a good value of about 7%.

[A] The type of acid component has some relationship to antistatic performance. Urethane acrylate prepolymers are the best, and epoxy acrylate prepolymers have the longest half-life.

This depends on the number of hydrophilic functional groups such as acryloyloxy groups contained in component [A]. The acid component [A], which has many hydrophilic functional groups, is itself useful for improving antistatic performance. If the composition of the present invention is applied to the surface of a synthetic resin molded product to form a thin film, and then polymerized and cured by ultraviolet irradiation, , an antistatic coating with excellent water resistance, heat resistance, abrasion resistance, and high mechanical strength can be obtained. Since this coating is transparent, it does not impair the color tone or appearance of the molded product. Therefore, the present invention provides a method that is far superior to the methods proposed so far for preventing electric shocks.

Examples are shown below.

Example / Urethane (meth)acrylate prepolymer, 3-chlorocohydroxypropyl methacrylate (Tobolene M [F] manufactured by Shin Nakamura Chemical) and benzyl dimethyl ketal (Irgakyu Roku bs manufactured by Ciba Geigy)) 3 fill
A polymethyl methacrylate transparent sheet of III×2θθ was immersed in the solution in the container for 7 minutes, and 20011
It was pulled up at a speed of 11/see and immediately irradiated with ultraviolet rays for 6 seconds using an ultraviolet irradiation device to polymerize and cure.

The irradiation lamp capacity is A 0W10n, and the seat position is I! ; The distance was Owg.

Table 1 shows the measurement results of antistatic performance, scratch resistance, surface electrical resistance, etc.

Electrostatic voltage: 10 KV, distance between electrode specimens: 25 m (the same applies hereinafter) The half-life numbers indicate the provision of charging properties, and the scratch resistance shows extremely good values, especially: ■=so:so.

The urethane (meth) acrylate prepolymer has the following structural formula, and its manufacturing method is a patent application! l,-! r/
No. 974.

Example coepoxy acrylate prepolymer 010 parts, 3-chloro-euhydroxypropyl methacrylate 090 parts,
Benzyl dimethyl ketal/part was mixed in a glass container, stirred, and allowed to stand. A sheet of polymethyl methacrylate (p<200 as) was immersed in the solution for 7 minutes and pulled out at a speed of 06 m7. Then, the coating film was immediately irradiated with ultraviolet light for 90 seconds to polymerize and cure the coating film. The measurement results of the obtained sheet are shown in Table 2.

The scratch resistance values in Table 1 are almost the same as those of the polymethyl methacrylate sheet, but the antistatic properties have a half-life of L2 seconds, which is a practical value.

The epoxy acrylate prepolymer (2) has the following structural formula.

Example 3 050 parts of urethane acrylate prepolymer, 3-chloro-1-hydroxypropyl methacrylate ■son
, neopentyl glycol diacrylate) and 2 parts of benzophenone were placed in a glass container, mixed, stirred and allowed to stand, heated to 10°C in an oil bath, and then added polymethyl to the solution at 0'C. methacrylate 1) (3
1111X 1001114 X/zOtaa) to 30
It was immersed for seconds, pulled up at a speed of 00 mII/WiR, and immediately irradiated with ultraviolet rays for 60 seconds to polymerize and cure the coating film. The measurement results of the obtained sheet are shown in the third column along with those of the sheet applied at room temperature.
Shown in the table.

13- The half-life of the sample coated at room temperature and polymerized and cured by UV irradiation was 735 seconds, and the antistatic performance was insufficient.

The urethane acrylate prepolymer (3) had the following structural formula.

Patent applicant: Asahi Kasei Industries, Ltd. Representative Patent Attorney Hoshi No Toru-da-

Claims (1)

[Claims] (1) a prepolymer [A] that is cured by ultraviolet irradiation in the presence of a photoinitiator, having at least 7 hydroxyl groups and at least one unsaturated group in the molecule;
1. An ultraviolet curable antistatic composition comprising a compound [B] having at the same time three halogen atoms, and a photopolymerization initiator [C] that absorbs light in the ultraviolet region.