JPH0149370B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention produces a cured product that has fast curing properties and has excellent hardness, toughness, and adhesion.
The present invention relates to a photocurable urethane (meth)acrylate prepolymer-containing composition useful as a coating film forming material, casting material, sealing material, molding material, sealing material, etc. In the present invention, (meth)acrylate refers to methacrylate and/or acrylate. [Problems to be Solved by the Invention] Recently, photocurable resins have been widely used, particularly in the fields of paints, inks, and adhesives. This means that photocurable resins have advantages such as making the coating film solvent-free, shortening the curing time, and extending the life of the resin tank, making it possible to save energy, save labor, and be pollution-free, which are the demands of the times. This is because it has been recognized. Currently, the high molecular weight unsaturated compounds, so-called prepolymers, which are the main components of photocurable resins, can be roughly divided into unsaturated polyester types, epoxy (meth) acrylate types, urethane (meth) acrylate types, and various ester (meth) There are four types of acrylate, among which urethane (meth)acrylate is
It is very promising for the future as it can form a strong coating film due to the electronic forces of the urethane group, and has good adhesion and processability. In fact, when producing urethane (meth)acrylate type, various modifications are possible depending on the reactivity of the isocyanate group, and by utilizing this modification, it is possible to improve physical properties to meet various needs. You can expect it. Nevertheless, at present, a cured film with sufficiently satisfactory physical properties, such as adhesion, hardness, and toughness, has not yet been obtained. [Prior art] Urethane (meth)acrylate prepolymers that have been proposed so far include, for example,
This is because, as disclosed in Japanese Patent Publication No. 41708 and Japanese Patent Publication No. 55-8013, the types of starting materials that are the constituent units of the prepolymer are extremely limited. For example, in urethane (meth)acrylate prepolymers produced using polyhydric alcohols, polyhydric isocyanates, and hydroxyl group-containing (meth)acrylates as starting materials, the polyhydric alcohol component is spiroglycol () (the structural formula is shown below). There are no examples using this in any of the previous patents, including the above patent. [Means for solving the problem] In view of the above situation, as a result of intensive studies, the present inventors produced a terminal isocyanate prepolymer by reacting a polyhydric isocyanate and a polyhydric alcohol, and the prepolymer In a urethane (meth)acrylate prepolymer obtained by reacting a hydroxyl group-containing (meth)acrylate with a spiroglycol represented by the following formula () as part or all of the polyhydric alcohol, A composition containing a urethane (meth)acrylate prepolymer represented by the following formula (), which is characterized by using The present inventors have discovered that this material exhibits excellent performance that has never been seen before, and have completed the present invention. (R ₁ is partly or completely R ₂ is a C ₁ to C ₃₀ hydrocarbon R ₃ is a C ₁ to _{C 30} hydrocarbon or an ester of dicarboxylic acid) [Function] The present invention will be explained in detail below. Examples of the polyvalent isocyanate which is one of the starting materials of the present invention include 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, m-phenylene diisocyanate, and p-phenylene diisocyanate. nylene diisocyanate,
1,5-naphthylene diisocyanate, 3,3'-
Dimethyl-4,4'-biphenylene diisocyanate, lysine diisocyanate, trans-1,4
Examples include cyclohexane diisocyanate, isophorone diisocyanate, etc., or adduct compounds thereof with water, trimethylolpropane, etc. Furthermore, as polyhydric alcohols, ethylene glycol, 1,2-propylene glycol, 1,3-
butylene glycol, trimethylene glycol,
1,6-hexanediol, diethylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, 2,2,4-trimethyl-
1,3-pentanediol, cyclohexanediol, dimethylolcyclohexane, alkylene oxide adducts of hydrogenated bisphenols, alkylene oxide adducts of halogenated bisphenols, 2,2-bis(4-hydroxycyclohexyl)propane, etc. Glycols with two terminal alcoholic hydroxyl groups, bis(hydroxyethyl) terephthalate, bis(hydroxyethyl) isophthalate, bis(2-hydroxypropyl) terephthalate, bis(2-hydroxypropyl)isophthalate, bis(4-hydroxy) Examples include diglycol esters of dicarboxylic acids such as (butyl) terephthalate. Furthermore, as the hydroxyl group-containing (meth)acrylate, ethylene glycol (meth)acrylate,
1,2-propylene glycol mono(meth)acrylate, trimethylene glycol mono(meth)
Acrylate, 1,4-butanediol mono(meth)acrylate, 2-butene-1,4-diol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, diethylene glycol mono(meth)acrylate, dipropylene Examples include glycol mono(meth)acrylates such as glycol mono(meth)acrylate. The present invention first focuses on polyhydric alcohols other than the above spiroglycol () and spiroglycol ().
Alternatively, spiroglycol () and a polyvalent isocyanate are charged in a ratio of hydroxyl groups per isocyanate group (OH/NCO)<1 (mol/mol) to produce a terminal isocyanate prepolymer. Here, spiroglycol () can be used in an amount of 10 to 100% by weight based on the total polyhydric alcohol. When the amount of spiroglycol () is less than 10% by weight, the properties resulting from the addition of spiroglycol do not appear. Further, this reaction may be carried out without a solvent or in a good solvent such as tetrahydrofuran or dimethylformamide. or,
Dibutyltin dilaurate, lead naphthenate, or the like may be added as a catalyst.Heating is preferably controlled so that the reaction temperature does not exceed 80°C. Next, the terminal isocyanate prepolymer obtained by this reaction is heated and reacted with a hydroxyl group-containing (meth)acrylate at a ratio of hydroxyl groups per isocyanate group (OH/NCO) ≧ 1 (mol/mol) to form urethane. A (meth)acrylate prepolymer is produced. At this time, a trace amount of a radical polymerization inhibitor may be added. Examples include hydroquinone, p-benzoquinone, p-cresol, and the like. It is preferable to control heating so that the reaction temperature does not exceed 80°C. The urethane (meth)acrylate prepolymer of the present invention can be used alone or in combination with other prepolymers, but this prepolymer is used after being diluted with a monomer, and the dilution rate is 100 parts by weight of the prepolymer. It is used in a range of 10 to 1000 parts by weight. Monomers as diluents include trimethylolpropane tri(meth)acrylate, 1,6-hexane glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and tetrahydrofurfuryl (meth)acrylate. ) acrylate, styrene, methyl (meth)acrylate, etc. and mixtures thereof. The urethane (meth)acrylate prepolymer of the present invention is suitably used for photocuring using a photopolymerization initiator, but of course it is also suitable for thermosetting using a suitable thermal polymerization initiator. [Example] The present invention will be described below with reference to Examples. In addition,
As a comparative example, a urethane acrylate prepolymer produced without adding spiroglycol was shown. Example 1 174 g (1 mole) of 2,4-tolylene diisocyanate [Tokyo Kasei Co., Ltd.] and 120 g of polyethylene glycol 400 (molecular weight) were placed in a four-necked flask equipped with a thermometer, a cooling tube, and a stirring device. (0.3 mol) and spiroglycol [Mitsubishi Gas Chemical Co., Ltd.] 91.4 g
(0.3 mol) (ratio to total polyhydric alcohol is 43.2% by weight)
was added and heated. The reaction temperature was maintained at around 80°C, and the reaction was carried out for about 3 hours. 0.02 g of hydroquinone monomethyl ether (MEHQ), 2-
Hydroxyethyl acrylate 116g (1.0mol)
added. At this time, the reaction temperature was kept at around 80℃.
The reaction was allowed to take place for about 3 hours. Styrene is added to the resulting reactant.
401g was added to prepare a resin liquid. Resin liquid obtained
Add 2g of benzoin ethyl ether to 100g,
A photocurable resin composition was obtained by uniformly mixing. Apply this photocurable resin composition onto a steel plate,
A coating film was obtained by standing still for 10 seconds and exposing it directly under a 10 cm high-pressure mercury lamp with an output of 120 W/cm. The physical properties of the resulting coating film are listed in Table 1. Comparative Example 1 174 g (1 mol) of 2,4-tolylene diisocyanate [Tokyo Kasei Co., Ltd.] and 240 g of polyethylene glycol 400 (molecular weight) were placed in a four-neck flask equipped with a thermometer, cooling tube, and stirring device. (0.6 mol) was added and heated. The reaction temperature was kept around 80℃, and the reaction temperature was kept at around 80℃.
Allowed time to react. To the obtained reaction product were added 0.02 g of hydroxy monomethyl ether (MEHQ) and 116 g (1.0 mol) of 2-hydroxyethyl acrylate. At this time, the reaction temperature was kept at around 80℃, and the
Allowed time to react. Styrene 424 is added to the resulting reactant.
g was added to prepare a resin liquid. Resin liquid obtained100
2 g of benzoin ethyl ether was added to g and mixed uniformly to obtain a photocurable resin composition. This composition was cured in the same manner as in Example 1. The physical properties of the coating film are shown in Table 1. Example 2 250 g (1 mol) of diphenylmethane diisocyanate [Tokyo Kasei Co., Ltd.] and 200 g (0.5 mol) of polyethylene glycol 400 (molecular weight) were placed in a four-necked flask equipped with a thermometer, a cooling tube, and a stirring device. ) and spiroglycol [Mitsubishi Gas Chemical Co., Ltd.] 30.4g
(0.1 mol) (ratio to total polyhydric alcohol is 13.2% by weight)
was added and heated. The reaction temperature was maintained at around 80°C, and the reaction was carried out for about 3 hours. 0.02 g of hydroquinone monomethyl ether (MEHQ), 2-
Hydroxyethyl acrylate 116g (1.0mol)
added. At this time, the reaction temperature was kept at around 80℃.
The reaction was allowed to take place for about 3 hours. Styrene is added to the resulting reactant.
477g was added to prepare a resin liquid. 100g of this resin liquid
2 g of benzoin ethyl ether was added to the mixture and mixed uniformly to obtain a photocurable resin composition. This composition was cured in the same manner as in Example 1. The physical properties of the coating film are shown in Table 1. Comparative Example 2 250 g (1 mol) of diphenylmethane diisocyanate [Tokyo Kasei Co., Ltd.] and 240 g (0.6 mol) of polyethylene glycol 400 (molecular weight) were placed in a four-necked flask equipped with a thermometer, cooling tube, and stirring device. ) was added and heated. The reaction temperature was kept at around 80℃, and the reaction temperature was kept at around 80℃.
Allowed time to react. 0.02 g of hydroquinone monomethyl ether (MEHQ) and 116 g (1.0 mol) of 2-hydroxyethyl acrylate were added to the obtained reaction product. At this time as well, the reaction temperature was maintained at around 80°C and the reaction was carried out for about 3 hours. Styrene is added to the resulting reactant.
A resin liquid was prepared by adding 485 g. 100g of this resin liquid
2 g of benzoin ethyl ether was added to the mixture and mixed uniformly to obtain a photocurable resin composition. This composition was cured in the same manner as in Example 1. The physical properties of the coating film are shown in Table 1. Example 3 In a four-necked flask equipped with a thermometer, a cooling tube, and a stirring device, 222 g (1 mol) of isophorone diisocyanate [Tokyo Kasei Co., Ltd.], 40 g (0.1 mol) of polyethylene glycol 400 (molecular weight), and 152 g (0.5 mol) of spiroglycol (Mitsubishi Gas Chemical Co., Ltd.) (ratio to total polyhydric alcohol: 79.2% by weight) was added and heated. The reaction temperature was maintained at around 80°C, and the reaction was carried out for about 3 hours. 0.02 g of hydroquinone monomethyl ether (MEHQ) and 116 g (1.0 mol) of 2-hydroxyethyl acrylate were added to the obtained reaction product. At this time, the reaction temperature was kept at around 80℃, and the
Allowed time to react. The physical properties of the obtained reaction product were as follows. chemical structure Average molecular weight 1500 Softening temperature Approximately 80℃ (white powder) Infrared spectrum As shown in Figure 1 (KBr-film) GPC (gel permeation chromatograph) Measurement conditions as shown in Figure 2 Column: TSK gel G4000HXL + G3000HXL + G2000HXL x 2 Solvent : Tetrahydrofuran 1 ml/min Detection : Differential refractometer 434 g of styrene was added to the above reaction product to prepare a resin liquid. 2 g of benzoin ethyl ether was added to 100 g of this resin liquid and mixed uniformly to obtain a photocurable resin composition. This composition was cured in the same manner as in Example 1. The physical properties of the coating film are shown in Table 1. Comparative Example 3 222 g (1 mol) of isophorone diisocyanate [Tokyo Kasei Co., Ltd.] and 240 g (0.6 mol) of polyethylene glycol 400 (molecular weight) were placed in a four-necked flask equipped with a thermometer, cooling tube, and stirring device. Add and heat. The reaction temperature was maintained at around 80°C, and the reaction was carried out for about 3 hours. 0.02 g of hydroquinone monomethyl ether (MEHQ) and 116 g (1.0 mol) of 2-hydroxyethyl acrylate were added to the obtained reaction product. At this time as well, the reaction temperature was maintained at around 80°C and the reaction was carried out for about 3 hours. 462g of styrene was added to the resulting reaction product.
was added to prepare a resin liquid. 2 g of benzoin ethyl ether was added to 100 g of this resin liquid and mixed uniformly to obtain a photocurable resin composition. This composition was cured in the same manner as in Example 1. The physical properties of the coating film are shown in Table 1.

[Table] ×...Crack occurrence [Effect of the invention] The urethane (meth)acrylate prepolymer-containing composition of the present invention is a new one, and is a curable resin composition that provides a cured product with excellent hardness, toughness, and adhesion. It can be made into a commercial product, and its industrial value is obvious.

[Brief explanation of drawings]

1 and 2 are an infrared chart diagram and a GPC diagram of a composition containing a urethane (meth)acrylate prepolymer according to Example 3 of the present invention.

Claims (1)

[Claims] 1 Spiroglycol, one or all of which is represented by the following formula () A urethane (meth)acrylate prepolymer represented by the following formula () obtained by reacting a terminal isocyanate prepolymer obtained by the reaction of a polyhydric alcohol and a polyvalent isocyanate with a hydroxyl group-containing (meth)acrylate. (R ₁ is partly or completely R ₂ is a C ₁ to C ₃₀ hydrocarbon R ₃ is a C ₁ to _{C 30} hydrocarbon or an ester of dicarboxylic acid, respectively), and 10 to 1000 parts by weight of a diluent (to 100 parts by weight of the prepolymer) A urethane (meth)acrylate prepolymer-containing composition containing a monomer).