JPS617235A - Polymerizable composition containing ester compound capable of being subjected to vinyl polymerization and preparation of ester compound thereof - Google Patents

Abstract

NEW MATERIAL:An ester compound capable of being subjected to vinyl polymerization shown by the formula I (R1 is acryloyl, or methacryloyl; R2 is H; a and b are a+b=4, 1<=a<=4, 0<=b<=3; R3 is methyl, or ethyl). EXAMPLE:Ditrimethylolpropane tetraacrylate. USE:Useful as an active ingredient for a photosensitive compositions. By containing this active ingredient, the composition has improved curing properties of surface hardness, wear resistance, adhesivity, flexibility, and chemical resistance by irradiation of ultraviolet rays or electron rays in an air atmosphere, useful in the field of coating compound, adhesive, ink, hard coat material, etc. PREPARATION:An alcohol shown by the formula II is reacted with a compound shown by the formula III [A is H, or methyl; X is -OH, OR (R is alkyl), or halogen] in the presence of a catalyst such as preferably sulfuric acid, etc. at 75- 120 deg.C, to give a compound shown by the formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel vinyl polymerizable material that forms a cured product with excellent surface hardness, abrasion resistance, flexibility, adhesion, stain resistance, chemical resistance, etc. The present invention relates to a polymerizable composition having an ester compound and a method for producing the ester compound. More specifically, the novel general formula (1): (wherein, R1 is an acryloyl group or a methacryloyl group, R2 is a hydrogen atom, a and b are a+b-4, 1≦a≦4.
A polymerizable composition capable of forming a cured product having improved curing properties, especially containing a vinyl polymerizable ester compound represented by an integer satisfying 0≦b≦3, where R3 represents a methyl group or an ethyl group. paints, adhesives, inks,
The present invention relates to a polymerizable composition that can be used in hard coating materials, etc., and a method for producing the ester compound.

[Prior Art] Currently, there are many ester compounds, and various photopolymerizable compositions containing these compounds, that is, UV-curable resins, are commercially available.

As a general photopolymerizable composition, Plasti-3
Paints and hard coat materials used to increase the surface hardness of single-piece products, aluminum products, brass products, etc., and prevent them from being damaged by collisions with other objects, contact, scratches, etc., and from losing their aesthetic appearance. There are also adhesives for glass and lenses, printing inks for metal cans, carton paper, business forms, etc., but current technology has poor abrasion resistance and poor adhesion between the coating film and the base material. However, it cannot be said that they have completely satisfactory characteristics.

The photopolymerizable composition described above is generally composed of an oligomer, an ester compound, a monofunctional monomer, a photopolymerization initiator, and various other additives. Note that the term "photopolymerization initiator" as used herein is a concept that also includes a sensitizer.

The ester compounds include ethylene glycol diacrylate, ethylene glycol methacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, and polyethylene glycol #400.
Diacrylate, polyethylene glycol #400 dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 1,6-
Hexanediol diacrylate, 1,6-hexanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol penta Acrylate, dipentaerythritol hexaacrylate, etc. are known. The selection and blending ratio of these ester compounds used in paints, inks, adhesives, etc. are extremely important for photopolymerizable compositions, and they affect not only the curing speed but also
It has a great effect on the physical properties of the cured coating, such as hardness, tensile strength, elongation, solvent resistance, abrasion resistance, adhesion, and adhesion.

For example, 1,6-hexanediol diacrylate extremely effectively lowers the viscosity of a photopolymerizable composition, but is said to have a significant negative effect on the physical properties of the cured product (Japanese Patent Laid-Open No. 176928/1983). Public bulletin).

Further, when trimethylolpropane triacrylate is used, although the adverse effect on the physical properties of the cured product is slight, it is not suitable for sufficiently lowering the viscosity of the photopolymerizable composition. Furthermore, pentafunctional monomers such as dipentaerythol pentaacrylate increase the crosslinking density of the cured product and increase its hardness, but on the other hand, it has the disadvantage that the adhesiveness with the substrate deteriorates. In addition, it is also known that certain ester compounds are highly irritating to the skin and are extremely difficult to handle.

Therefore, as a photopolymerizable composition, various oligomers,
Development of ester compounds that, when mixed with monofunctional monomers, have low skin irritation, provide appropriate viscosity, have a high curing speed, and provide excellent properties such as hardness, abrasion resistance, and adhesion of the cured product. desired.

[Summary of the Invention] The present inventors have developed a technology that has improved curing properties, that is, excellent surface hardness, abrasion resistance, adhesion, flexibility, and durability in the fields of paints, adhesives, inks, hard coat materials, etc. The present invention was completed as a result of repeated studies to develop a photopolymerizable composition containing an ester compound capable of producing a cured product having chemical properties.

That is, the present invention provides a polymerizable composition containing a vinyl-polymerizable ester compound represented by the general formula (1) (hereinafter referred to as an ester compound represented by the general formula (1)) and a polymerizable composition containing the general formula (2): (wherein, R3 is the same as above) and general formula (3): % formula % (wherein A is a hydrogen atom or a methyl group, X is -OH, -
The present invention relates to a method for producing an ester compound represented by general formula (1), which is characterized by reacting a compound represented by OR (R represents an alkyl group or a halogen atom).

The main objective of the present invention is to improve surface hardness, abrasion resistance, adhesion, and
The object of the present invention is to provide a polymerizable composition containing a novel ester compound that provides cured physical properties with excellent flexibility and chemical resistance, and a method for producing the ester compound.

[Embodiments of the Invention] The method for producing the novel ester compound of the present invention will be described in detail.

The ester compound represented by general formula (1) of the present invention is
It can be produced by reacting the alcohol represented by the general formula (2) with the compound represented by the general formula (3).

For example, when acrylic acid or methacrylic acid is used as the compound represented by general formula (3) and an esterification reaction is performed between this and an alcohol represented by general formula (2) (hereinafter referred to as alcohol (2)), the reaction conditions are as follows: should be selected appropriately depending on the esterification of the desired product,
The preferred range of conditions is as follows. First, the amount of acrylic acid or methacrylic acid to be charged is suitably 1 to 8 times mole, preferably 4 to 6 times mole, relative to alcohol (2).

As a catalyst for the esterification reaction, acidic catalysts such as sulfuric acid, p-toluenesulfonic acid, phosphoric acid, and hydrochloric acid are preferably used, and the amount used is 1 to 20% (by weight) based on the charged alcohol (2). %, the same applies hereinafter), preferably 1 to 10
It is x.

When carrying out the esterification reaction, a solvent is not necessarily required, but if used, it has low solubility in water,
It is advantageous to use a solvent which has a boiling point of about 60 DEG to 140 DEG C. at normal pressure and is azeotropic with water. As such a solvent,
Examples include aliphatic hydrocarbons such as n-hexane and n-hebutane; aromatic hydrocarbons such as benzene, toluene and xylene; and alicyclic hydrocarbons such as cyclohexane. When using a solvent, the amount used is 30 to 500%, especially 50% to the amount of ester produced.
About 200% is preferable.

The temperature at which the esterification reaction is carried out is preferably in the range of 60 to 140°C, but from the viewpoint of shortening the reaction time and preventing polymerization, it is advantageous to carry out the esterification reaction in the range of 75 to 120°C.

Generally, a polymerization inhibitor is already added to acrylic acid and methacrylic acid, but a polymerization inhibitor may be additionally added during the reaction. Such polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, p-methoxyfurol, t-butylcatechol, 2,4-dimethyl-6-t-butylphenol, α
-Nitroly β-naphthol, copper salts, etc. are mentioned, and are usually added in an amount of about 0.01 to 1% to the reaction mixture.

Polymerization can also be prevented by blowing air into the reaction solution.

In the esterification reaction, for example, a mixed solution consisting of alcohol (2), acrylic acid or methacrylic acid, a catalyst, a polymerization inhibitor, and a solvent is charged into a reactor equipped with a water separator, and the water produced as the solvent boils is removed. This can be carried out by reacting while removing by azeotropy with a solvent.

When the reaction is a transesterification reaction between alcohol (2) and an alkyl ester of acrylic acid or methacrylic acid, which is a compound represented by the general formula (3), the alkyl ester is an alcohol having 1 to 4 carbon atoms. Esters such as methyl acrylate, ethyl acrylate,
It is desirable to use methyl methacrylate, ethyl methacrylate, or the like because the alcohol produced in the reaction can be easily distilled off.

When carrying out the transesterification reaction, the appropriate amount of the alkyl ester to be charged is 1 to 8 times the mole of alcohol (2). When the alkyl ester is used in excess, it is not necessary to use a particular reactor medium, but a solvent such as benzene, 0-hexinane, or cyclohexane may be used. Moreover, as a catalyst, any acid or alkali used in a normal transesterification reaction can be used.

When the ester compound represented by the general formula (1) is produced by transesterification, the same amount of polymerization inhibitor as in the case of esterification reaction may be added and the reaction may be carried out by adding air to the reaction solution. It is also possible to prevent polymerization by injecting

In the Nisdell exchange reaction, for example, a mixed solution consisting of alcohol (2), an alkyl ester of acrylic acid or methacrylic acid, a solvent, a polymerization inhibitor, and a catalyst is charged into a reactor equipped with a fractionator, and the alkyl ester, solvent, and reaction mixture are charged into a reactor equipped with a fractionator. This can be carried out while distilling off the alcohol produced under boiling.

Regardless of the type of reaction, the ester compound represented by the general formula (1) can be extracted from the reaction solution by, for example, washing the reaction mixture with water, neutralizing it with alkaline water, etc., and then removing the ester compound. It is desirable to separate and collect the containing layer, and if necessary, purify it with activated carbon or the like, then recover the solvent and obtain the residue as the target product.

The polymerizable composition of the present invention has the general formula (2) as described above.
The photopolymerizable composition contains an ester compound represented by the following formula, and by adding other components such as an oligomer, a polymerizable polymer, and a photopolymerization initiator, the photopolymerizable composition cures at a practical speed. be able to.

Next, the polymerizable composition will be explained.

Examples of the oligomer include adducts and condensates of unsaturated polyesters, epoxy compounds, polyisocyanate compounds such as diisocyanate compounds, or polyol compounds with acrylic acid or methacrylic acid.

Further, examples of the polymerizable polymer include monofunctional polymers or polyfunctional monomers that can be polymerized with vinyl, and specific examples thereof include styrene, α-methylstyrene, 2
-vinylpyridine, 4-vinylpyridine, methyl acrylate, methyl methacrylate, diethylaminoethyl methacrylate, 2-ethylhexyl methacrylate,
2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, tohydroxymethyl acrylamide, tohydroxymethyl methacrylamide, polyethylene glycol monoacrylate, glycerin diacrylate, glycerin dimethacrylate, trimethylol Examples include propane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol trimethacrylate, and pentaerythritol tetramethacrylate.

As the pre-light distribution polymerization initiator, it is desirable to use a sensitizer for active energy rays such as ultraviolet rays and electron beams, but the invention is not limited thereto. Specific examples of the sensitizer include benzoin, benzoin methyl ether, benzoin ethyl ether, benzyl, benzophenone,
Examples include acetophenones, thioxanthone, and azobisisobutyronitrile.

If a thermal polymerization catalyst such as an organic peroxide such as benzoyl peroxide or a radical polymerization initiator is blended instead of the photopolymerization initiator, the material can be rapidly cured at room temperature to elevated temperature without photopolymerization. You can also do that.

The polymerizable composition may contain various stabilizers, deterioration inhibitors, foaming agents, antifoaming agents, colorants, pigments, etc., as long as they do not interfere with photopolymerization.
A gelling agent, a viscosity modifier, a filler, etc. may be added.

The proportion of each component in the photopolymerizable composition of the present invention cannot be determined generally, but in general it is 0 to 90 parts (by weight or less, the same), preferably 40 to 80 parts of the oligomer, and 100 to 10 parts, preferably 60 to 20 parts of the ester compound represented by the general formula (1), so that the total amount is 100 parts. You can use it as When the photopolymerization initiator is added in an amount of about 1 to 10% to the prepolymer blend thus prepared, the photopolymerizability of the prepared polymerizable composition is significantly enhanced.

The polymerizable composition containing the ester compound represented by the general formula (1) is fast-curing and provides a cured product with good physical properties. In other words, it has the property of being rapidly cured by irradiation with ultraviolet rays, electron beams, etc. in the presence of a photopolymerization initiator, or at room temperature or elevated temperature in the presence of a radical polymerization initiator. Has excellent hardness,
It has wear resistance, adhesion, flexibility, chemical resistance, stain resistance, etc. Therefore, the polymerizable composition of the present invention provides a composition that is particularly useful as a UV-curable resin for paints, inks, adhesives, hard coats, and the like. Of course, the ester compound represented by the general formula (1) according to the present invention may be used alone, and a polymerization initiator may be added thereto for curing. Furthermore, various resins may be used as reactive diluents and crosslinking agents. There is no problem in using it for modification.

Further, when the ester compound represented by the general formula (1) according to the present invention is tetrafunctional or trifunctional, the curing rate is extremely fast and the crosslinking density is high, so that when the ester compound is used in the polymerizable composition of the present invention. Additionally, it exhibits extremely excellent cured physical properties. If it is difunctional or monofunctional, the curing time will be slightly longer, but the physical properties of the cured product will not be essentially adversely affected.

In addition, the ester compound represented by the general formula (1) has a pH value of 0.9 obtained in a temporary skin irritation test (see reference side), a similar product trimethylolpropane triacrylate (PII 2.2 ~3.75), pentaerythritol tetraacrylate (pH 2,5~4,
Compared to 3), skin irritation is extremely low.

Next, the present invention will be explained based on Examples, but the present invention is not limited thereto.

Example 1 In a 211 glass flask equipped with a stirrer, reflux condenser, water separator, thermometer, and air inlet, 200 g of ditrimethylolpropane, 346 g of acrylic acid, 20 g of sulfuric acid,
Copper sulfate O, gg, hydroquinone 0.8 g, and benzene 360 g were charged, and while stirring, air was blown in at a flow rate of 40 d/min, and the mixture was heated and heated for 5 hours. During heating to reflux, water was separated from the distilled benzene-water distillation valve through a water separator, and the benzene was continuously returned to the reaction flask.

The amount of distilled water separated by the water separator was 60 g.

After the reaction, the reaction solution was cooled, washed with water, neutralized with a 10% aqueous sodium hydroxide solution, and washed with a 10% aqueous NaCl solution repeatedly, and then the benzene layer was taken out and the benzene was distilled off under reduced pressure at 50°C or less. . The residue was treated with activated carbon 2 and filtered to yield 3009 product.

The obtained product was confirmed to be ditrimethylolpropane tetraacrylate from the results of elemental analysis and ester value analysis. Elemental analysis value theoretical value (%): H7,35C61,79 analysis value (%)
): H7,41C61,74 ester value Theoretical value = 482 Analysis value: 484 The above theoretical values are all related to ditrimethylolpropane tetraacrylate.

Example 2 Ditrimethylolpropane 10 was added to the same apparatus as in Example 1.
0g, acrylic acid 61g, sulfuric acid 109, sulfuric acid amount 0.36
g, hydroquinone 7 methyl ether o, ia g and 100 g of cyclohexane, and air 20Id/
The reaction was carried out in the same manner as in Example 1 while blowing at a flow rate of 14.5 g, and 14.5 g of water was distilled out.

After the reaction was completed, it was treated in the same manner as in Example 1, = 19
- 130 g of product obtained.

The obtained product as a whole is a bifunctional acrylate represented by the general formula (1) (R+ = C1tz = Cl1
CO-1R2=ll, R3--C2It5, a=2
, b=2) was confirmed by the results of elemental analysis and ester value analysis.

Elemental analysis value theoretical value (%): H8,38C60,34 analysis value (%)
) : H8,33C60,36 esterification theoretical value: 313 Analytical value: 320 Example 3 95 parts of di-1-limethylolpropane tetraac obtained in Example 1, 3 parts of benzophenone, 2 parts of dimethylaminoethanol A photopolymerizable composition was prepared. The photopolymerizable composition was applied to the plastic plate shown in Table 1 whose surface had been wiped with alcohol using a bar coater of No. The coating film was cured by irradiating it with light for 20 seconds using MiniCure 450) in the air.

The hardness, adhesion, and abrasion resistance of the resulting cured coating film were measured by the following methods. The results are shown in Table 1.

(hardness) Evaluated by pencil hardness according to JIS 5401-1969.

(Adhesion) Cross cut according to JIS K 5400-1979
Evaluated by Sellotape peel test.

(Abrasion resistance) The coating surface was rubbed once with 0000 yen steel wool and evaluated according to the following criteria.

A: No scratches even when rubbed strongly B: Slight scratches when rubbed strongly C: Slight scratches when rubbed lightly D: Significant scratches even when lightly rubbed < Example 4 Used in Example 3 A photopolymerizable composition was prepared in the same manner as in Example 3, except that the compound obtained in Example 2 was used instead of ditrimethylolpropane tetraacrylate,
Painted on a plastic plate. After that, when I irradiated it for 20 seconds, it hardened, but it seemed to be a little sufficient, so I tried 3
The coating film was cured by irradiation with light for 0 seconds, and the properties of the coating film were evaluated in the same manner as in Example 3. The results are shown in Table 1.

Comparative Example 1 Trimethylolpropane triacrylate (SartOller, USA) was used instead of ditrimethylolpropane tetraacrylate used in Example 3.
A composition was prepared in the same manner as in Example 3, except that R-351) was used, and it was applied to a plastic plate and irradiated with light for 30 seconds, but it did not harden.

From the results in Table 1, it can be seen that the composition using the ester compound represented by the general formula (1) has fast curing properties, and is particularly excellent in fast curing properties when the ester compound is tetrafunctional. Recognize. Furthermore, it can be seen that the cured coating film obtained from the composition has excellent properties such as extremely good adhesion to plastic plates and abrasion resistance, and extremely high hardness of 7■.

Example 5 20 parts of ditrimethylolpropane tetraacrylate obtained in Example 1, 65 parts of epoxy acrylate (Celrad 3701, manufactured by Celanese Plastics and Specialties, Inc., USA), 2-
A photopolymerizable composition was prepared consisting of 10 parts of ethylhexyl acrylate, 5 parts of N-vinylpyrrolidone, 5 parts of benzoylethyl ether, 0.5 part of di-n-butyltin maleate, and 0.5 part of tetramethylthiuram monosulfide. did.

The pre-light distribution polymerizable composition was uniformly applied to a plastic plate shown in Table 2 similar to that used in Example 3 using a bar coater of 8, and then immediately coated in the air using MiniCure 450. The coating film was cured by irradiation with light for 5 seconds.

The hardness and adhesion of the obtained cured coating film were measured in the same manner as in Example 3. The results are shown in Table 2.

Comparative Example 2 A photopolymerizable composition was prepared in the same manner as in Example 5, except that dipentaerythritol pentaacrylate (5R-399 from Sartomer, Inc., USA) was used instead of ditrimethylolpropane tetraacrylate, and a coating film was formed. The cured coating properties were evaluated. The results are shown in Table 2.

[Left below] Table 2 From the summary in Table 2, it can be seen that the photopolymerizable composition using the ester compound represented by the general formula (1) has an extremely fast curing property, and the resulting cured coating film has a hardness of ,W! It can be seen that it has excellent adhesion.

Reference Example A ditrimethylolpropane tetraacrylate application test was carried out using six healthy white-breasted chicks weighing 2.0 to 3.0 kg, with four 2 x 2 inch test sites placed on their backs. Characteristic values for irritation include erythema and floating lungs, 4.2
Characteristic values were scored at 4.48 hours, and the total average PII of the six animals was 0.9.

Claims (1)

[Claims] 1 General formula (1): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) (In the formula, R_1 is an acryloyl group or a methacryloyl group, R_2 is a hydrogen atom, and a and b are a+b=4 , 1≦a≦
4. A polymerizable composition containing a vinyl polymerizable ester compound represented by an integer satisfying 0≦b≦3, R_3 represents a methyl group or an ethyl group. 2. The polymerizable composition according to claim 1, which is an ultraviolet or electron beam curable composition. 3 General formula (2): ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (2) Alcohol represented by (in the formula, R_3 represents a methyl group or ethyl group) and general formula (3): ▲ Numerical formulas, chemical formulas, There are tables, etc.▼(3) (In the formula, A is a hydrogen atom or a methyl group, X is -OH, -
The general formula (R represents an alkyl group or a halogen atom)
1): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) (In the formula, R_1 is an acryloyl group or methacryloyl group, R_2 is a hydrogen atom, a and b are a+b=4, 1≦a≦
4, an integer satisfying 0≦b≦3, R_3 represents a methyl group or an ethyl group) A method for producing a vinyl polymerizable ester compound.