JP5709702B2 - Acrylamide derivatives with little yellowing - Google Patents

Description

The present invention relates to acryloylmorpholine which is less likely to be colored or discolored by heat even when stored for a long time after production, and relates to a resin composition as a coating agent containing the acryloylmorpholine and useful as various coating materials. Further, the present invention relates to a method of making a coating material containing acryloylmorpholine a component that hardly causes coloring or discoloration even when exposed to a high temperature after forming a coating film on the surface of the substrate.

In recent years, as an alternative to transparent plate glass, resin molded products have been widely used because they are lightweight and have excellent mechanical properties and workability. In particular, resin molded products manufactured from polymethyl methacrylate resin, polymethacrylimide resin, polycarbonate resin, polystyrene resin, etc. are also excellent in transparency, so as a structural member that changes to glass, for windows such as buildings and vehicles, It is used for various purposes such as instrument covers.

However, these resin molded products are inferior in surface characteristics such as scratch resistance, weather resistance, heat resistance, chemical resistance, etc. compared to glass, so it is desired to improve the surface characteristics. A coating process is commonly used.

For surface coating treatment, for example, a method of laminating an acrylic resin film or the like on the surface of a resin molded product, or a coating agent made of a silicon or melamine resin composition is applied to the surface of the resin molded product, followed by heat condensation and crosslinking. There are a method of forming a film, a method of applying a UV curable resin composition comprising a radical polymerizable monomer such as an acrylamide derivative to the surface of a resin molded product, and irradiating active energy rays to form a coating film.

Of these surface coating treatments, a method of forming a coating film by applying an ultraviolet ray curable resin composition composed of a radical polymerizable monomer and irradiating active energy rays is often used because of its high productivity. (Japanese Patent Laid-Open No. 2010-65232). As the radical polymerizable monomer in the resin composition, acryloylmorpholine is preferably used among acrylamide derivatives because of advantages such as low viscosity, high curability, adhesion to a substrate, and transparency. In particular, acryloyl morpholine is transparent for car headlights, instrument covers, lighting fixture covers, TV screens, mobile phone screens, etc. because it dissolves other monomers, oligomers and polymers well and exhibits excellent transparency. It is very suitable as a component of the surface coating agent for parts in which safety is essential.
However, there has been a problem that a coating film formed by applying a resin composition containing acryloylmorpholine to a substrate and curing it tends to yellow due to thermal history. Especially when the base material is an electric product such as a car light, an instrument cover, a television, a lighting device, or an electric heating device, it is often exposed to high temperature or long-term heat, and it may be colored over time to impair the appearance. there were. Therefore, there has been a problem that a large amount of acryloylmorpholine cannot be blended in the resin composition.

In general, as a method for preventing yellowing, it is common to add an antioxidant, a light stabilizer, a heat stabilizer and the like to the resin composition in advance (Japanese Patent Laid-Open No. 2010-170125). Addition of the above-described antioxidant or the like can prevent deterioration in physical properties and yellowing due to oxidation deterioration of the coating film which is a resin molded product. However, as far as the yellowing due to the thermal history of the coating film using acryloylmorpholine was concerned, no effect was seen with commonly used antioxidants.

In JP-A-2002-338611, a curable composition comprising a (meth) acrylic acid ester monomer having a hydroxyl group, a phenolic antioxidant, a phosphorus antioxidant, an ultraviolet absorber and a hindered amine light stabilizer is cured. It is disclosed that the cured product is excellent in transparency and low colorability. However, the polymerizable monomer used in this curable composition is a (meth) acrylic acid ester monomer, and the phenolic antioxidant, phosphorous antioxidant described in the same document for acryloylmorpholine, When an ultraviolet absorber and a hindered amine light stabilizer are used, there are problems such as worsening the paintability (film forming property) to the substrate and further worsening yellowing.

In JP 2006-193650 A, a cured product made from a curable composition using a combination of an acrylate monomer, a phenol-based antioxidant, and a sulfur-based antioxidant retains hardness in a heat aging test, It is disclosed that it is excellent in non-coloring properties. However, when phenolic antioxidants and sulfur antioxidants described in the same document are used in combination with acryloylmorpholine, a sufficient yellowing suppression effect can be obtained by coloring the sulfur antioxidant itself. There wasn't.

JP 2009-096955 discloses that an optical film containing acryloylmorpholine as an ethylenically unsaturated monomer and an ultraviolet absorber is less colored during heat processing, a phenol-based, hindered amine-based, or phosphorus-based antioxidant. Is desirable. However, when an ultraviolet absorber is added in such an amount that a sufficient effect can be obtained, poor curing is caused, and phenol-based antioxidants, hindered amine-based antioxidants, phosphorus-based antioxidants specifically described in the same document Addition of the agent did not provide the desired yellowing suppression effect over time, leaving room for improvement.

JP 2010-65232 A JP 2010-170125 A JP 2002-338611 A JP 2006-193650 A JP 2009-096955 A

To obtain a method for preventing yellowing due to thermal history of a coating film using acryloylmorpholine.
Moreover, the acryloyl morpholine which is used as a resin composition component of a coating agent and whose coating film after curing does not yellow with time due to heat is obtained.

   As a result of intensive studies to solve such problems, the present inventors have found that acryloylmorpholine is acryloylmorpholine by adding a phenolic antioxidant represented by the general formula [I], and a resin composition using the acryloylmorpholine. It was found that yellowing with time was suppressed. Moreover, it discovered that yellowing could be suppressed more effectively by adding tertiary amine.

（２）前記フェノール系酸化防止剤が２，５’−ジ−ｔ−ブチルハイドロキノンまたは２，５’−ジ−ｔ−アミルハイドロキノンであることを特徴とする、上記（１）記載のアクリロイルモルホリン、
（３）前記フェノール系酸化防止剤の含有量が０．１〜１０重量％であることを特徴とする、上記（１）または（２）に記載のアクリロイルモルホリン、
（４）アクリロイルモルホリンと、前記一般式［Ｉ］
（式中、R₁は、炭素数１〜５の直鎖または分枝鎖のアルキル基を示す。）で示されるフェノール系酸化防止剤と、３級アミンとを含有することを特徴とする樹脂組成物、
（５）上記（４）に記載の樹脂組成物を樹脂成型品の表面に塗布し、活性エネルギー線を照射することによりコーティング膜を形成させた樹脂成型品、
（６）アクリロイルモルホリンを配合した樹脂組成物を基材の表面に塗布し、活性エネルギー線を照射することによりコーティング膜を形成させる方法において、該樹脂組成物に前記一般式［Ｉ］
（式中、R₁は、炭素数１〜５の直鎖または分枝鎖のアルキル基を示す。）で示されるフェノール系酸化防止剤と３級アミンとを含有させることを特徴とする、該コーティング膜の黄変を抑制する方法
に係るものである。 That is, the present invention
(1) A phenolic antioxidant represented by the general formula [I] (wherein R ₁ represents a linear or branched alkyl group having 1 to 5 carbon atoms) and a tertiary amine. Acryloylmorpholine, characterized by

(2) The acryloylmorpholine according to the above (1), wherein the phenolic antioxidant is 2,5′-di-t-butylhydroquinone or 2,5′-di-t-amylhydroquinone,
(3) The acryloylmorpholine according to (1) or (2) above, wherein the content of the phenolic antioxidant is 0.1 to 10% by weight,
(4) acryloylmorpholine and the general formula [I]
(Wherein R ₁ represents a linear or branched alkyl group having 1 to 5 carbon atoms) and a tertiary amine. Composition,
(5) A resin molded product in which a coating film is formed by applying the resin composition described in (4) above to the surface of a resin molded product and irradiating an active energy ray,
(6) In a method of forming a coating film by applying a resin composition containing acryloylmorpholine to the surface of a substrate and irradiating an active energy ray, the resin composition is represented by the general formula [I].
(Wherein R ₁ represents a linear or branched alkyl group having 1 to 5 carbon atoms) and a phenol containing a tertiary amine, and a tertiary amine, The present invention relates to a method for suppressing yellowing of a coating film.

The acryloyl morpholine of the present invention is not only an excellent monomer as a raw material for a coating agent in terms of heat resistance, low viscosity, high curability, and transparency, but a coating film using the acryloyl morpholine has a high temperature and long-term heat It is hard to yellow.
In addition, according to the method of the present invention, a coating film which is hardly yellowed can be obtained from acryloylmorpholine obtained by a usual method by a simple method. Thereby, acryloylmorpholine can be used also as a coating agent for articles having a large thermal history.
In addition, since it does not easily yellow, acryloylmorpholine can be incorporated in resin compositions in large quantities, improving the weather resistance, heat resistance, scratch resistance (coating film hardness), chemical resistance, etc. of the substrate. Can be made.

Hereinafter, the present invention will be described in detail.
The acryloylmorpholine of the present invention contains a phenolic antioxidant represented by the general formula [I] (wherein R1 represents a linear or branched alkyl group having 1 to 5 carbon atoms). The Among them, 2,5′-di-t-butylhydroquinone and 2,5′-di-t-amylhydroquinone, in which R ₁ is a compound represented by a methyl group or an ethyl group in the formula of the general formula [I], Desirably, specific examples include “ANTAGE DBH” and “ANTAGE DAH” manufactured by Kawaguchi Chemical Industry.

In general, the amount of the phenolic antioxidant added is preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight in acryloylmorpholine. Moreover, when it sees from the resin composition which mix | blended this acryloyl morpholine, it is desirable that the addition amount is 0.15-1.5 weight%. If the amount added is less than this, no effect on yellowing suppression can be expected, and if it is more than this amount, the curing of the resin composition by irradiation with active energy rays is inhibited, and further, the cost becomes disadvantageous.

The acryloylmorpholine of the present invention contains a tertiary amine in combination with the phenol-based antioxidant, thereby further effectively suppressing yellowing.
The type of tertiary amine is not particularly limited. For example, N-methylaniline, N- (2-hydroxyethyl) aniline, N, N-dimethylaniline, 4-t-butyldimethylaniline, N-methyl-p- Toluidine, N, N-dimethyl-p-toluidine, N, N-dihydroxyethyl-p-toluidine, triethylamine, tripropylamine, tributylamine, ethylenediethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine N-methyl-N, N-diethanolamine, triethanolamine, tetramethylethylenediamine, tetramethylpropanediamine, tetramethylhexanediamine, 4-dimethylaminophenylethanol, 3-dimethylaminobenzoic acid and the like. These may be used alone or in combination of two or more. Among these, it is preferable to use N, N-dimethyl-p-toluidine from the viewpoint of the synergistic effect with the phenolic antioxidant.

The addition amount of the tertiary amine is desirably 0.01 to 10% by weight in acryloylmorpholine, and more desirably 0.05 to 5% by weight. Moreover, when it sees from the resin composition which mix | blended this acryloyl morpholine, it is desirable that the addition amount is 0.015-1.5 weight%.

The acryloylmorpholine of the present invention is mixed with another polymerizable monomer to obtain a resin composition.
The phenolic antioxidant and tertiary amine may be contained in the resin composition, and may be added to acryloylmorpholine, added to other monomers, mixed, You may add after becoming this resin composition.
When the resin composition is applied to a substrate and then irradiated with active energy rays, the resin composition is crosslinked to form a coating film.
When curing by irradiation with active energy rays, the resin composition is preferably applied on the substrate so as to have a film thickness of 1 to 50 μm, more preferably 3 to 20 μm, and a high-pressure mercury lamp, a metal halide lamp or the like is used. Then, an ultraviolet ray having a wavelength of 340 nm to 380 nm is irradiated so as to be 200 to 1000 mJ / cm ² . The atmosphere to be irradiated may be air or an inert gas such as nitrogen or argon.

The coating film using acryloylmorpholine of the present invention can be used to modify the surface properties of various resin molded articles as the base material, but as this resin molded article, various thermoplastics that have been requested to improve the weather resistance have hitherto been used. Examples thereof include resins and thermosetting resins. Specific examples include polymethyl methacrylic resin, polycarbonate resin, polyester resin, polystyrene resin, ABS resin, AS resin, polyamide resin, polyarate resin, polymethacrylimide resin, and polyallyl diglycol carbonate resin. In particular, since polymethyl methacrylic resin, polycarbonate resin, polystyrene resin, and polymethacrylimide resin are excellent in transparency, it is particularly effective to use a coating film using acryloylmorpholine of the present invention. The resin molded product is a sheet-shaped molded product, a film-shaped molded product, various injection molded products, or the like made of these resins.

As described above, in the acryloylmorpholine of the present invention and the composition thereof, and the coating film using the acryloylmorpholine of the present invention, yellowing can be suppressed over a long period of time.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. Various physical properties described in the claims and examples of the present invention were determined according to the following measuring methods.

<Yellowness>
The coating film formed by the active energy ray is subjected to a heat resistance test in which the coating film is heated at 120 ° C. for 10 days as an acceleration test. Several points were measured using Kogyo Co., Ltd. And the difference ((DELTA) b * value) of b * value was calculated | required from L * a * b * as a yellowing degree calculated from the measured value.

Example 1:
0.5% by weight of 2,5′-di-t-amylhydroquinone (Kawaguchi Chemical Industry Co., Ltd. “ANTAGE DAH”) as a phenolic antioxidant and 0, N, N-dimethyl-p-toluidine as a tertiary amine 90% by weight of acryloylmorpholine (Kojin Co., Ltd.) added by 3% by weight, 10 parts by weight of isobornyl acrylate (Daicel Cytec Co., Ltd.), and an ultraviolet curing initiator (trade name “Darocur 1173” manufactured by BASF) After applying a mixed solution of 2 parts by weight on a PET film (100 mm square) so as to have a film thickness of 5 μm, a coating film was obtained by irradiating an integrated light quantity of 1000 mJ / cm ² with a high-pressure mercury lamp.

Example 2:
Example 1 Example 1 except that 2,5′-di-t-butylhydroquinone “ANTAGE DBH” was added in place of 2,5′-di-t-amylhydroquinone as the phenolic antioxidant in Example 1. In the same manner, a coating film was obtained.

Example 3:
In Example 1, a coating film was obtained in the same manner as in Example 1 except that N, N-dimethylaniline was added as a tertiary amine instead of N, N-dimethyl-p-toluidine.

Example 4:
In Example 1, a coating film was obtained in the same manner as in Example 1 except that N-methyl-N, N-diethanolamine was added as a tertiary amine instead of N, N-dimethyl-p-toluidine.

Example 5:
In Example 1, a coating film was obtained in the same manner as in Example 1 except that triethanolamine was added as a tertiary amine instead of N, N-dimethyl-p-toluidine.

Example 6:
In Example 1, a coating film was obtained in the same manner as in Example 1 except that tetramethylethylenediamine was added as a tertiary amine instead of N, N-dimethyl-p-toluidine.

Example 7:
In Example 1, a coating film was obtained in the same manner as in Example 1 except that tetramethylpropanediamine was added as a tertiary amine instead of N, N-dimethyl-p-toluidine.

Comparative Example 1:
90 parts by weight of acryloylmorpholine (Kojin Co., Ltd.) with no addition, 10 parts by weight of isobornyl acrylate (Daicel Cytec Co., Ltd.), and an ultraviolet curing initiator (trade name “Darocur 1173” manufactured by BASF) After coating a mixed solution of 2 parts by weight on a PET film (100 mm square) so as to have a film thickness of 5 μml, a coating film was obtained by irradiating an integrated light quantity of 1000 mJ / cm ² with a high-pressure mercury lamp.

Comparative Example 2:
90 parts by weight of acryloylmorpholine (Kojin Co., Ltd.) to which 0.5% by weight of 2,5′-di-t-amylhydroquinone (Kawaguchi Chemical Industry Co., Ltd. “ANTAGE DAH”) was added as a phenolic antioxidant, A PET film (100 mm square) with a mixed liquid consisting of 10 parts by weight of bornyl acrylate (Daicel Cytec Co., Ltd.) and 2 parts by weight of an ultraviolet curing initiator (trade name “Darocur 1173” manufactured by BASF) to a film thickness of 5 μm. ) After coating on, a coating film was obtained by irradiating an integrated light quantity of 1000 mJ / cm ² with a high-pressure mercury lamp.

Comparative Example 3:
In Example 1, instead of 2,5′-di-t-amylhydroquinone, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (trade name “Irganox 1076”, Ciba Except for the addition of Specialty Chemicals), the coating was performed on the PET film in the same manner as in Example 1, but the coating film could not be obtained because the wettability with respect to the substrate deteriorated.

Comparative Example 4:
In Example 1, in place of 2,5′-di-t-amylhydroquinone, Example 1 except that an imidazole antioxidant mercaptobenzimidazole (trade name “ANTAGE MB”, manufactured by Kawaguchi Chemical) was added. In the same manner, a coating film was obtained.

Comparative Example 5:
In Example 1, instead of 2,5′-di-t-amylhydroquinone, the phosphorus antioxidant bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite ( A coating film was obtained in the same manner as in Example 1 except that the trade name “PEP-36” (manufactured by ADEKA) was added.

Comparative Example 6:
In Example 1, instead of 2,5′-di-t-amylhydroquinone, the phosphorus-based antioxidant tris (2,4-t-butylphenyl) phosphite (trade name “Irgafos168”, Ciba Specialty Chemicals) The coating film was not obtained because the wettability with respect to the base material was deteriorated.

The coating films obtained in Examples 1 to 7 and Comparative Examples 1 to 6 were stored in a hot air dryer at 120 ° C. (RH 75%) for 10 days, and then the Δb * value was measured. The results are shown in Table 1.

As shown in Table 1, 0.5% by weight of 2,5′-di-t-butylhydroquinone or 2,5′-di-t-amylhydroquinone as a phenolic antioxidant is 0.3% of tertiary amine. By using acryloylmorpholine contained in wt%, the yellowing degree Δb * value can be suppressed to 1 or less. Incidentally, the Δb * value within 1 indicates the degree to which yellowing cannot be judged visually.

As described above, the acryloylmorpholine of the present invention is less prone to yellowing over a long period of time even when a coating film using the acryloylmorpholine is subjected to high temperature or long-term heating conditions. Therefore, it can be suitably used as a resin component of the surface coating agent of a resin molded product.

Claims (5)

An acryloylmorpholine, a phenolic antioxidant represented by the general formula [1] (wherein R ₁ represents a linear or branched alkyl group having 1 to 5 carbon atoms), a tertiary amine, A polymerizable composition comprising:

The polymerizable composition according to claim 1, wherein the phenolic antioxidant is 2,5′-di-t-butylhydroquinone or 2,5′-di-t-amylhydroquinone. The polymerizable composition according to claim 1 or 2, wherein the content of the phenolic antioxidant is 0.1 to 10% by weight. The resin molded product which formed the coating film by apply | coating the polymeric composition as described in any one of Claims 1-3 to the surface of a resin molded product, and irradiating an active energy ray. Acryloyl morpholine polymerizable composition containing coated on the surface of the substrate, a method of coating film is formed by irradiation with an active energy ray, general formula to the polymerizable composition [2] (wherein, R ₁ represents a linear or branched alkyl group having 1 to 5 carbon atoms.) The phenolic antioxidant represented by (3) and a tertiary amine are contained, and the yellowing of the coating film How to suppress.