JP3744685B2 - Photocurable resin composition - Google Patents

Description

を仕込み、1時間かけて混練した後、120℃に加熱した4-インチオープンロールでフィルム化し、厚さ0.5mmの薄膜を作成した。
【００３４】
この薄膜に、ウシオ電気製高圧水銀ランプを用いて、UV強度56mw/cm²、照射距離24cmの条件下で紫外光を10秒間、30秒間または60秒間照射し、光硬化反応を行った。得られた硬化薄膜について、参考例1と同様にしてウォーレス硬度(Hw)および伸張伸びの測定を行ない、また硬化薄膜の硬化度合を確認するために次のような試験を行った。
キシレンによる表面ラビング試験[試験I]:
キシレンを含浸させた10枚重ねのガーゼを硬化薄膜上に押し当て、8往復擦った後の硬化薄膜表面を目視で観察し、異常なし○、傷、白化などが小を△、大を×、溶解を××として評価した
耐傷付き性試験[試験II]:
流水中で硬化薄膜表面に亀の子たわしを押し当て、20往復擦った後の硬化薄膜表面を目視で観察し、異常なし○、傷が小を△、大を×、傷が大で不透明になったものを××として評価した
【００３５】
実施例２
実施例1で、メタクリル系共重合体A量を80g(50重量部)に、また3官能性アクリレートオリゴマー量を80g(50重量部)に変更し、更にシリカ(日本アエロジル製品アエロジル#200)20g(12.5重量部)が添加されて用いられた。
【００３６】
実施例３
実施例1で、メタクリル系共重合体Aの代りにメタクリル系共重合体Bが、また3官能性アクリレートオリゴマーの代りに4官能性アクリレートオリゴマー(東亜合成製品アロニックスM-400)が、それぞれ同量用いられた。
【００３７】
実施例４
実施例1において、メタクリル系共重合体Aの代りに、同量のメタクリル系共重合体Cが用いられた。
【００４２】
比較例１
メタクリル系共重合体D単独の熱プレスおよび紫外線照射物について、実施例1と同様の測定および試験が行われた。
【００４３】
比較例２
メタクリル系共重合体E単独の熱プレスおよび紫外線照射物について、実施例1と同様の測定および試験が行われた。
【００４４】
比較例３
実施例1において、メタクリル系共重合体Aの代りに、同量のメタクリル系共重合体Eが用いられた。
【００４６】
以上の各実施例および比較例における測定結果は、次の表2に示される。
表２
測定・試験 UV照射 実施例 比較例
項目 ( 秒 ) 1 2 3 4 1 2 3
硬度(Hw) 10 93 98 92 90 100 82 97
30 97 99 97 95 100 85 99
60 99 99 99 98 100 88 99
伸び (%) 10 60 100 80 80 0 390 140
30 40 25 40 40 0 420 110
60 15 0 0 20 0 450 20
試験I 10 × × × × ×× ×× ××
30 △ △ △ △ ×× ×× ××
60 ○ ○ △ △ ×× ×× ××
試験II 10 × × × × × × ×
30 △ △ △ △ × × ×
60 ○ ○ ○ ○ × × △
【００４７】
以上の結果から、次のようなことがいえる。
(1)各実施例と比較例1〜2との対比から、既知の熱可塑性樹脂と比較して、キシレンラビング性の向上が確認され、また十分なる耐傷付き性を有していることが分る。
(2)各実施例と比較例3との対比から、共重合体側鎖に導入されたメトキシ - またはエトキシ - エチレン鎖が多官能性アクリレートと反応し、複合化したことによるキシレンラビング性の向上が確認される。 [0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photocurable resin composition. More specifically, the present invention relates to a photocurable resin composition capable of providing a photocured film having excellent solvent resistance and scratch resistance.
[0002]
[Prior art]
For automobile exteriors, ABS resin, polypropylene resin, vinyl chloride resin, polymethyl methacrylate resin, polycarbonate resin, etc. have been used in the past, and for the purpose of surface decoration, substrate protection, etc., acrylic resin type, Solvent-based paints such as urethane resin systems and silicone resin systems are used, but non-solvent paints are required particularly from the viewpoint of preventing environmental pollution.
[0003]
In order to meet these demands, water-based paints, powder paints, etc. have already been put into practical use. However, water-based paints are inferior in drying properties, so not only drastic improvements in the drying process are required, Auxiliary equipment such as temperature and humidity control and wastewater treatment equipment is required. On the other hand, the standard thickness of powder coatings increases the amount of use, leading to an increase in price, as well as low temperature curability, paint appearance, There are problems such as weather resistance and flexibility, and none of them has completely surpassed solvent-based paints.
[0004]
In contrast to conventional coating methods, it has been proposed to use a thermoplastic resin film that can be integrally formed with an exterior part from the viewpoint of coating-free (Japanese Patent Laid-Open No. 3-147719). This is because a thermoplastic resin film having a curable resin film formed on one side is produced, and this and the exterior component are integrally molded, and the thermoplastic resin is pressure-bonded to the surface of the exterior component, thereby It is intended to give the same coating properties as paint. However, this is inferior in deep drawability (workability) and has a disadvantage of large trimming loss, and is not satisfied as an alternative to solvent-based paints.
[0005]
Furthermore, there is a method in which a composition comprising a photocurable monomer represented by a polyfunctional polyacrylate and a photopolymerization initiator is applied to an exterior part and then subjected to a curing reaction by light irradiation to form a resin. In some cases, there are practical problems such as low impact resistance of the cured product and poor flexibility.
[0006]
Further, 100 parts by weight of an acrylic rubber having an unsaturated double bond group in the side chain, 0.05 to 20 parts by weight of a polyfunctional unsaturated monomer, 0.01 to 10 parts by weight of a photocrosslinking initiator, 10 to 100 parts of amorphous silica A photo-crosslinkable acrylic rubber composition containing parts by weight (and 0.1 to 5 parts by weight of an aliphatic amine) has been proposed (Japanese Patent Laid-Open No. Hei 9-00383). Since the hardness is lower than that of the conventional coating film, practically sufficient coating performance cannot be obtained.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a photocurable resin composition that is excellent in solvent resistance and scratch resistance and can provide a photocured film having practically sufficient hardness.
[0008]
[Means for Solving the Problems]
The purpose of such invention, methyl methacrylate least by polymerizing 25 wt% copolymer of methoxy in the side chain - or ethoxy - methacrylic copolymer having an ethylene group, a polyfunctional unsaturated monomers and photocrosslinking initiator It is achieved by a photocurable resin composition containing
[0009]
It is a feature of the present invention, methoxy in the side chain is a light curable resin component - or ethoxy - as a copolymer having an ethylene group, from about 25 wt% at least methyl methacrylate, generally from about 30 to 80 weight %, Preferably about 35 to 75% by weight of copolymerized methacrylic copolymer.
[0010]
The acrylic rubber which is a photocurable component described in JP-A-9-003833 is an alkyl acrylate and / or alkoxyalkyl acrylate 55 to 99.99% by weight and an unsaturated double bond which is a crosslinking point in the side chain. It is said that 0.01 to 20% by weight of the monomer to be introduced essentially consists of 0 to 20% by weight of monomers copolymerizable therewith, but there are alicyclic alcohols. Or only aromatic methacrylate methacrylate is described, and no description on methyl methacrylate is found.
[0012]
Methacrylic copolymer of such a ratio in the present invention obtained by copolymerizing methyl methacrylate, methoxy in the side chain as photocrosslinkable groups - having an ethylene group - or ethoxy.
[0013]
Methoxy to the side chain - or ethoxy - introduction of ethylene groups are methoxy - or ethoxy - having an ethylene group (meth) acrylate of about 1 to 70 wt%, row by preferably polymerizing about 5 to 60 wt% Co Is called. Examples of such (meth) acrylates include alkoxyalkyl acrylates such as 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate, acrylates such as ethoxydiethylene glycol monoacrylate, methoxytriethylene glycol monoacrylate, methoxypolyethylene glycol monoacrylate and the like. At least one methacrylate is used.
[0014]
In addition to the above essential copolymerization components, alkyl (meth) acrylates other than methyl methacrylate such as methyl acrylate, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, pentyl, isopentyl, hexyl, 2-ethylhexyl, octyl , Nonyl, decyl, lauryl, stearyl and the like and at least one of the corresponding methacrylic acid esters (excluding methyl esters), about 70
The copolymerization can be carried out at a ratio of not more than% by weight, preferably about 5 to 60% by weight.
[0015]
In addition to the above (meth) acrylic acid esters, vinyl monomers copolymerizable therewith, such as styrene, α-methylstyrene, halogenated styrene, vinyl toluene, vinyl pyridine, vinyl naphthalene, (meth) acrylonitrile, About 20% by weight or less of (meth) acrylamide, N-methylolacrylamide, vinyl acetate, vinyl chloride, vinylidene chloride, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, or divinylbenzene, divinyltoluene, divinylxylene, divinylnaphthalene , Divinyl sulfone, divinyl ketone, divinyl ether, ethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and the like can be further copolymerized at a ratio of about 10% by weight or less.
[0018]
The copolymerization reaction can be performed by any polymerization method such as suspension polymerization, emulsion polymerization, solution polymerization, and the polymerization rate is 90% or more, so the proportion of the comonomer used is almost as it is. The composition of the copolymer. The obtained methacrylic copolymer has a Mooney viscosity ML _{1 + 4} (125 ° C.) according to JIS K-6300 of about 10 to 100, preferably about 20 to 80.
[0019]
The methacrylic copolymer has about 1 to 200 parts by weight, preferably about 10 to 100 parts by weight of polyfunctional unsaturated monomer, about 0.01 to 20 parts by weight, preferably about 0.1 to 100 parts by weight per 100 parts by weight. 10 parts by weight of a photocrosslinking initiator is added, and further, if necessary, about 200 parts by weight or less, preferably about 10 to 100 parts by weight of amorphous silica is added to form a photocrosslinkable resin composition.
[0020]
Examples of polyfunctional unsaturated monomers include alkylene glycol diacrylates such as ethylene glycol diacrylate and propylene glycol diacrylate, polyalkylene glycol diacrylates such as polyethylene glycol diacrylate and polypropylene glycol diacrylate, and isocyanuric acid ethylene oxide modified Acrylic acid esters such as triacrylate, trimethylolpropane ethylene oxide modified triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, dimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, or the corresponding methacrylic acid esters, triaryl Rucyanurate, triallyl isocyanurate, N, N'- At least one such as m-phenylene dimaleimide is used, and acrylic acid ester type is preferably used from the viewpoint of reactivity to ultraviolet irradiation.
[0021]
The photocrosslinking initiator is a compound that easily decomposes by light irradiation to give a radical and is not particularly limited. For example, acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, p-dimethylamino Acetophenones such as propylacetophenone, p-tert-butyltrichloroacetophenone, benzophenone, 2-chlorobenzophenone, p, p'-dichlorobenzophenone, benzophenones such as p, p'-bisdimethylaminobenzophenone, benzyl, benzoin, benzoin n At least one of benzoin ethers such as propyl ether, benzyl ketals such as benzyl dimethyl ketal and benzyl methyl ketal, benzoylbenzoate, and α-acyloxy esters such as benzyl (o-ethoxycarbonyl) α-monooxime It is needed.
[0022]
Furthermore, the amorphous silica added as necessary may be either dry silica or wet silica, such as precipitated silica, airgel silica, fumed silica, and surface-treated silica obtained by treating these surfaces with an organic silyl group or the like. At least one type is used.
[0023]
In addition to these components, ultraviolet absorbers for improving weather resistance, antioxidants, lubricants for improving processability, plasticizers, various pigments for adjusting the color of coatings, polyfunctional unsaturated mono-monomers. A composition can be prepared by appropriately blending a polymerization inhibitor or the like for suppressing premature polymerization of the monomer.
[0024]
The photocurable resin composition is prepared using a closed kneader such as an open roll mixer or a kneader, a single screw extruder, a twin screw extruder, an extrusion kneader, or the like. Alternatively, the composition can also be prepared by adding a necessary compounding agent to a latex of a methacrylic copolymer obtained by suspension polymerization or emulsion polymerization or a solution-polymerized methacrylic copolymer solution and drying. .
[0025]
The photocurable resin composition thus prepared is formed into a film by a hot roll, pelletized by a pelletizer, etc., and then formed into a thin film by an open roll, a tube by an extruder, a sheet insert molding, a multilayer injection After adhesive molding on various substrate surfaces such as metal, plastic, electric wire, glass, etc. by molding, etc., it is photocured by irradiation with light such as ultraviolet rays and visible light, and various sheet materials, tubes, gaskets, packing, surface coating materials, etc. To form.
[0026]
【The invention's effect】
Since the photocurable resin composition according to the present invention has a practically sufficient hardness and moderate elongation after photocuring, it can be used for various sheet materials, tubes, gaskets, packing, surface treatment agents for desks and metal products, and soundproof walls. It can be used effectively for applications such as cover materials.
[0027]
In particular, from the viewpoint of appearance such as solvent resistance, scratch resistance, abrasion resistance, and gloss of photocured products, ABS resin for automobiles, vinyl chloride resin, polymethyl methacrylate resin, polycarbonate resin exterior resin parts It can be suitably used as a surface coating material. Moreover, the film formed there does not pollute the environment and has film performance comparable to that of solvent-based paints.
[0028]
【Example】
Next, the present invention will be described with reference to examples.
[0029]
Reference example 1
In a 3 L separable flask equipped with a stirrer, thermometer, nitrogen gas inlet tube and decompression device, methyl methacrylate 225 g (45 wt%), 2-methoxyethyl acrylate 275 g (55 wt%), sodium lauryl sulfate 27.5 g and 750 ml of water were charged, and degassing and nitrogen gas replacement were repeated to sufficiently remove oxygen in the system.
Sodium hydrosulfite 0.05g
Sodium formaldehyde sulfoxylate 0.01g
Tertiary butyl hydroperoxide 0.025g
The polymerization initiator which consists of was added, and the polymerization reaction was started at room temperature.
[0030]
Thereafter, the reaction at 50 ° C. was continued for 6 hours until the polymerization conversion rate reached 98%, and the obtained aqueous latex was salted out, washed with water and dried, and the Mooney viscosity ML _{1 + 4} (125 ° C.) was 56. 490 g of methacrylic copolymer A was obtained.
[0031]
This copolymer was pressed under conditions of 150 ° C, 200Kg / cm ² G, 1 minute to form a film with a thickness of 0.5mm, and when this was measured for Wallace hardness (Hw), a value of 61 was obtained. Further, when the elongation elongation (based on JIS K-6301; elongation speed: 500 mm / min) was measured, a value of 435% was obtained.
[0032]
Reference Examples 2 to 5
In Example 1, the monomer composition was variously changed, and the results shown in Table 1 below were obtained.
Table 1
Reference example
2 Three Four Five
[Monomer composition; wt%]
Methyl methacrylate 30 50 100 50
2-Methoxyethyl 10
Acrylate ethyl acrylate 60
n-Butyl acrylate 40 50
Methoxytriethylene 10
Glycol acrylate
[Methacrylic copolymer]
Abbreviation BC D E
Polymerization rate (%) 96.2 97.7 94.0 96.6
Mooney viscosity ML _{1 + 4} 63 56 - 51
[Film characteristics]
Hardness (Hw) 36 47 100 81
Elongation (%) 740 260 0 395
[0033]

After kneading for 1 hour, the film was formed into a 4-inch open roll heated to 120 ° C. to form a thin film having a thickness of 0.5 mm.
[0034]
This thin film was irradiated with ultraviolet light for 10 seconds, 30 seconds or 60 seconds under the conditions of a UV intensity of 56 mw / cm ² and an irradiation distance of 24 cm using a high pressure mercury lamp manufactured by Ushio Electric to carry out a photocuring reaction. The obtained cured thin film was measured for Wallace hardness (Hw) and elongation elongation in the same manner as in Reference Example 1, and the following test was performed to confirm the degree of curing of the cured thin film.
Surface rubbing test with xylene [Test I]:
Pressed 10 layers of gauze impregnated with xylene on the cured thin film, visually observed the cured thin film surface after 8 reciprocating rubbing, no abnormality ○, scratches, whitening etc., small △, large × Scratch resistance test where dissolution was evaluated as XX [Test II]:
Press the tortoise scourer against the cured thin film surface in running water, visually observe the cured thin film surface after 20 reciprocating rubbings, no abnormality ○, small scratch △, large ×, scratch large and opaque Was evaluated as XX.
Example 2
In Example 1, the amount of methacrylic copolymer A was changed to 80 g (50 parts by weight), the amount of trifunctional acrylate oligomer was changed to 80 g (50 parts by weight), and silica (Japan Aerosil product Aerosil # 200) 20 g (12.5 parts by weight) was added and used.
[0036]
Example 3
In Example 1, the same amount of methacrylic copolymer B instead of methacrylic copolymer A, and the same amount of tetrafunctional acrylate oligomer (Toa Gosei product Aronix M-400) instead of trifunctional acrylate oligomer. Used.
[0037]
Example 4
In Example 1, instead of methacrylic copolymer A, the same amount of methacrylic copolymer C was used.
[0042]
Comparative Example 1
The same measurement and test as in Example 1 were performed on the hot press and ultraviolet irradiation product of methacrylic copolymer D alone.
[0043]
Comparative Example 2
Measurements and tests similar to those in Example 1 were carried out on the methacrylic copolymer E alone in the heat press and the ultraviolet irradiated product.
[0044]
Comparative Example 3
In Example 1, instead of methacrylic copolymer A, the same amount of methacrylic copolymer E was used.
[0046]
The measurement results in the above examples and comparative examples are shown in the following Table 2.
Table 2
Measurement / Test Example of UV irradiation Comparative example
Item ( seconds ) 1 2 3 4 1 2 3
Hardness (Hw) 10 93 98 92 90 100 82 97
30 97 99 97 95 100 85 99
60 99 99 99 98 100 88 99
Elongation (%) 10 60 100 80 80 0 390 140
30 40 25 40 40 0 420 110
60 15 0 0 20 0 450 20
Test I 10 × × × × ×× ×× ××
30 △ △ △ △ ×× ×× ××
60 ○ ○ △ △ ×× ×× ××
Test II 10 × × × × × × ×
30 △ △ △ △ × × ×
60 ○ ○ ○ ○ × × △
[0047]
From the above results, the following can be said.
(1) From the comparison between each example and Comparative Examples 1 and 2, it was confirmed that the xylene rubbing property was improved as compared with known thermoplastic resins, and that it had sufficient scratch resistance. The
(2) from the comparison between Comparative Example 3 and each example, methoxy introduced into the copolymerization side chain - or ethoxy - ethylene chain is reacted with multifunctional acrylates, improved xylene rubbing resistance due to the composite Confirmed .

Claims (2)

At least methyl methacrylate is polymerized copolymer 25 wt%, methoxy in the side chain - or ethoxy - methacrylic copolymer having an ethylene group, a polyfunctional unsaturated monomers and light-curing comprising a photocrosslinking initiator Resin composition. Claims further containing amorphous silica 1 The photocurable resin composition as described.