JPH028211A - Production of ultraviolet-or radiation-curable resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition suitable for coating material, ink, etc., by reacting a polyvalent isocyanate with an acid diol and reacting the reaction product successively with a polyhydric alcohol, a polyvalent isocyanate and a hydroxyl-containing (meth)acrylate. CONSTITUTION:The objective composition is produced by (1) reacting (A) a polyvalent isocyanate such as tolylene diisocyanate with (B) an acid diol such as 2,2-di(hydroxymethyl)propionic acid e.g., at 70-120 deg.C to obtain an adduct compound, (2) adding and reacting (C) a polyhydric alcohol such as polyethylene glycol to the adduct compound, (3) again reacting the component A and (4) reacting the reaction product with (D) a hydroxyl-containing (meth)acrylate such as 2-hydroxyethyl (meth)acrylate.

Description

Detailed Description of the Invention (A) Purpose of the Invention Industrial Application Field The present invention relates to an ultraviolet or radiation curing type coating material useful for paints, inks, conductive paints, etc. that use radiation such as ultraviolet rays or electron beams as a curing means. The present invention relates to a method for producing a resin composition, and the composition according to the present invention has excellent cured film properties such as mechanical properties and transparency, as well as excellent adhesion and dispersibility to metals and metal oxides. It is something that you have.

PRIOR ART Urethane (meth)acrylates have various chemical structures depending on the combination of their manufacturing raw materials, namely alcohols, isocyanate compounds, and hydroxyl group-containing (meth)acrylates, and some of them have already been developed. It is commercially available and used for various purposes. On the other hand, technology that hardens resin with radiation such as ultraviolet rays and electron beams
It continues to develop as an alternative technology to conventional heat curing from the perspectives of improving line speed, saving resources, and protecting the environment.

Production technology using radiation curing has been widely developed for paints, inks, conductive paints, etc., but it cannot be said that it has reached a satisfactory level. It is mentioned that the urethane (meth)acrylate used does not yet have both excellent cured coating JIIK percentage properties and good adhesion and dispersibility to metals and metal oxides.

Problems to be Solved by the Invention As mentioned above, although there have been a wide variety of urethane (meth)acrylates, we have developed a urethane that has excellent cured film properties and has excellent adhesion and dispersibility to metals and metal oxides. (Meth)acrylate is still unknown.

Under these circumstances, the present invention has developed a urethane (metallic urethane) that has extremely excellent mechanical properties, transparency, and adhesion to metal substrates, as well as excellent adhesion and dispersibility to metals and metal oxides. ) The present invention aims to provide a method for producing an ultraviolet or radiation curable resin composition containing acrylate as a curable component.

(b) Means for solving the structural problems of the invention In the field of paints, inks, conductive paints, etc., mechanical properties of binder resins used in these are always a problem.1 Surface gloss, transparency, Cured film has properties such as adhesion to materials.

Among ultraviolet or radiation-curable resins, urethane (meth)acrylate is often used for these purposes because of the toughness of the cured coating. However, urethane (meth)acrylate has the disadvantage of insufficient adhesion to metal substrates, as well as adhesion to pigments such as metals and metal oxides, which is required for binder resins for K, inks, and conductive paints. or dispersibility is insufficient. In order to improve the dispersibility of metals and metal oxides, improvements in molecular weight and molecular structure, as well as the addition of dispersants with polar groups, are often carried out. However, the latter method is not preferred because it causes changes over time due to surface migration of the dispersant after curing.

As a result of intensive studies, the present inventors found that an ultraviolet or radiation resin composition consisting of urethane (meth)acrylate having a carboxyl group in the molecule has excellent mechanical properties, transparency, surface gloss, and is suitable for metal substrates. It was found that the cured coating film properties such as adhesion of 100% and excellent adhesion and dispersibility to metals and metal oxides were obtained.

Regarding urethane (meth)acrylate having a carboxyl group in the molecule, JP-A-61-18610 discloses a method in which a polyhydric alcohol containing 2,2-(dihydroxymethyl)propionic acid and a polyhydric isocyanate are reacted all at once. It is known to be produced by producing a terminal isocyanate urethane oligomer and reacting this with a hydroxyl group-containing (meth)acrylate. According to this production method or a production method in which 2.2-(dihydroxymethyl)propionic acid is replaced with other acid diol as a raw material, a compound <1> having an average structure shown below is produced.

-(M-X)A-M-R<1> However, R: Residue of hydroxyl group-containing (meth)acrylate M: Residue of polyvalent isocyanate X: 2.2-(dihydroxydylmethyl)propionic acid or Other acid diol residues t: Indicates a positive number, and 1M and X are bonded by a urethane bond.

This compound <1> has poor compatibility with various other ultraviolet or radiation-curable tops and oligomers. Since the chemical compound (I) causes phase separation, there are problems such as decreased toughness of the coating film, cloudiness, decreased surface gloss, and decreased adhesion to metal substrates.

Under these circumstances, the present inventors found that compounds <1
An ultraviolet- or radiation-curable resin composition containing carboxyl group-containing urethane (meth)acrylate with a minimum content of > has excellent mechanical properties, transparency, surface gloss, and adhesion to metal substrates. The inventors have discovered that the present invention forms a cured coating film with excellent adhesion and dispersibility to metals and metal oxides, and as a result of repeated studies on the production method, the present invention has been completed.

Next, a method for producing the carboxyl group-containing urethane (meth)acrylate-containing composition of the present invention will be explained.

Raw material O Hydroxyl group-containing (meth)acrylate Examples of hydroxyl group-containing (meth)acrylates that can be used in the present invention include the following. 2-hydroxyethyl (meth)acrylate, 2-
Hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, C-caprolactone adduct of 2-hydroxylethyl (meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol triacrylate, etc.

O Polyvalent Isocyanate Examples of polyvalent isocyanates that can be used in the present invention include diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, and methyllysine diisocyanate; 2.4.6-) Triisocyanates such as luent isocyanate can be mentioned. More preferred among these are diisocyanates.

O Polyhydric alcohol The polyhydric alcohol used in the present invention may be dihydric or higher, but dihydric alcohol is more preferable. The alcohol mentioned here refers to a compound having a hydroxyl group in the molecule other than acid diol, such as a) saturated polyester polyol b) unsaturated polyether polyol c) polyether polyol d) polycaprolactone polyol e) fatty acid ester, etc. Specific examples thereof are as follows.

b) Saturated polyester polyol ethylene glycol, propylene glycol, neopentyl glycol, 12-butylene glycol, t3-butylene glycol, 14-butylene glycol, 1.6
- Contains a hydroxyl group, which can be obtained by the esterification reaction between polyhydric alcohols such as hexanediol and trimethylolpropane and saturated polybasic acids such as phthalic acid, isophthalic acid, succinic acid, adipic acid, and sepacic acid. Saturated polyester polyol.

b) Unsaturated polyester polyol An unsaturated polyester polyol having a hydroxyl group obtained by substituting a part of the polybasic acid in the saturated polyester polyol of above a) with a polybasic acid having an unsaturated bond such as maleic acid.

c) Polyether polyol polyethylene glycol, polypropylene glycol,
Polytetramethylene glycol and propylene oxide adduct of glycerin (trade name: Nirasanuniol TG-
1000), ethylene oxide adduct of bisphenol A (
Polyether polyols such as product name: Nirasan Uniol DA-400).

2) Polycaprolactone polyol A ring-opening polymer of e-caprolactone, examples of commercially available products include Placcel L-205AL and Placcel
Examples include L-212AL (manufactured by Daicel Chemical Industries, Ltd.).

e) Fatty acid ester A hydroxyl group-containing fatty acid ester synthesized from fatty acids or synthetic fatty acids and polyhydric alcohols.The fatty acids used as raw materials include soybean oil, peanut oil, cottonseed oil, safflower oil, olive oil, and castor oil. Among them, castor oil is particularly preferably used. Other polyhydric alcohol raw materials include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and trimethylolpropane.

In addition to the polyhydric alcohols shown in (i) to (e) above, polybutadiene having a terminal hydroxyl group and the like can also be used. Moreover, there is no problem in using two or more of these alcohols at the same time.

0 acid diol The acid diol used in the present invention is a dihydric alcohol having at least one carboxyl group in the molecule, such as 2,2-di(hydroxymethyl)propionic acid having one carboxyl group, 2,2-di(hydroxymethyl)butyric acid, tartaric acid having two carboxyl groups, and the like can be used.

Production method A resin composition containing carboxyl group-containing urethane (meth)acrylate forms a cured coating film with excellent mechanical properties, transparency, surface gloss, and adhesion to metal substrates, and is suitable for use with metals and metal oxides. In order to exhibit sufficient adhesion and dispersibility to the compound, it is important to minimize the amount of by-product of compound (I) during production. As methods for producing carboxyl group-containing urethane (meth)acrylate for this purpose, the following two methods are extremely excellent.

The first method is as follows: 1> First, a terminal isocyanate acid diol adduct compound (A) is produced from an acid diol and a polyvalent isocyanate. At this time, the charging ratio of acid diol and polyvalent isocyanate is as follows: NCO group 10H group>1 (
molar ratio) is desirable, and more desirable is NC'0 group 10
H group≧2 (molar ratio). Further, the reaction temperature at this time is preferably 70 to 120°C, more preferably 80 to 11°C.
It is 0°C. When the reaction temperature is lower than 70°C, it is difficult to complete the reaction of the acid diol, and on the other hand, when it is higher than 120°C, gelation is likely to occur due to side reactions.

(2) Subsequently, the terminal isocyanate acid diol adduct compound (A) produced in the previous step is reacted with a polyhydric alcohol to produce a terminal hydroxyl group urethane oligomer (B).

At this time, the charging ratio of terminal isocyanate acid diol adduct compound (A) and polyhydric alcohol is OH group/NC
O group>1 (molar ratio) is desirable.

<3> Furthermore, the hydroxyl-terminated urethane oligomer (B) produced in the previous step is mixed with a polyvalent isocyanate, preferably N
A terminal isocyanate urethane oligomer (C) is produced by adding and reacting at a ratio of CO group 10H group>1 (molar ratio).

4> Finally, in <3>, [the produced terminal isocyanate urethane oligomer (C) is added and reacted with a hydroxyl group-containing (meth)acrylate, preferably in a ratio such that OR group/NCO group ≧1, to form a carboxyl group-containing urethane. (meta)
Manufacture acrylate.

The second method is a manufacturing method in which the following steps <5> and <3> are performed instead of the above steps <3> and <4>. That is, <5> polyvalent isocyanate and hydroxyl group-containing (meth)acrylate, preferably NCO group 10H group ≧2 (molar ratio)
Terminal isocyanate (meth)acrylate adduct Q)) is produced by adding and reacting in a ratio such that the terminal isocyanate (meth)acrylate adduct Q))

<3> The above-mentioned terminal isocyanate (meth)acrylate adduct ■) and the terminal hydroxyl group urethane oligomer (B) produced in Part 2> are preferably added in a ratio of OH group/NCO group ≧1 to perform a reaction to obtain a carboxyl group-containing product. Manufactures urethane (meth)acrylate.

In addition, the above steps <3> and <4> or <5> and <3>
In this case, it is preferable to add a polymerization inhibitor such as phenols such as hydroquinone and hydroquinone monomethyl ether, quinones such as benzoquinone, phenothiazine, and copper salt.

Furthermore, there is no problem in using a catalyst for the urethanization reaction or a reaction solvent in all of the above steps. As a catalyst for the urethanization reaction, for example, triethylamine,
Tertiary amines such as N-methylmorpholine, N,N,N',N'-tetramethyl-1,3=butanediamine, organotin compounds such as tin octoate, dibutyltin dilaurate, or 'rtINalKIVtFe1
Metal salts of Mnlpb, etc. can be used. - reaction solvents include ketone solvents such as methyl etone ketone, methyl isobutyl ketone, and cyclohexanone, ester solvents such as ethyl acetate and butyl acetate, aromatic hydrocarbon solvents such as benzene, xylene, and toluene, and other solvents. Preferably used.

The amount of catalyst and solvent used in each of the above steps, the reaction temperature in steps 3 and 4, or steps 2, 5 and 3, and steps 3 and 4 or 5 and The reaction conditions such as the amount of polymerization inhibitor used in 3> are as follows:
Just follow the usual rules.

Carboxyl group-containing urethane produced by the present invention (
The average structure of meth)acrylate can be expressed as shown in the following formula when dihydric alcohol and divalent isocyanate are used as raw materials.

R-E-M-N-(M-Y)k-M),,-N)n-M
-R where, R: residue M of hydroxyl group-containing (meth)acrylate, residue N of divalent isocyanate, residue Y of dihydric alcohol, number no of positive number m'0.7 or more in the residue of acid diol. , a number of 7 or more, and R, M, N and Y are bonded by a urethane bond.

In the above structural formula, k, m and n can be controlled by the reaction molar ratio of the raw material compounds, and preferably k is a positive number of 10 or more, more preferably 0.1 or more, and m or n is 0. It is .7 or more and 10 or less, more preferably 1 or more. When k exceeds 10, the viscosity of the product becomes high, leading to a decrease in workability, and the curability with ultraviolet rays or radiation becomes poor. If m or n is less than α7, the adhesion of the product to metals and the dispersibility to metal oxides may deteriorate; if it exceeds 1o, the viscosity of the product will increase, resulting in decreased workability and UV rays. Alternatively, radiation may cause a decrease in curability.

Curing of Composition The resin composition produced according to the present invention is easily cured by irradiation with ionizing radiation such as ultraviolet rays, X-rays, and electron beams.

When the curing method is ultraviolet irradiation, use as a polymerization initiator [
A photoinitiator is used. Examples of photoinitiators often used industrially include benzoin alkyl ether and benzophenone N.

Examples include N'-diethylaminobenzophenone, 2,2-jethoxyacetophenone, λ2-dimethoxy-2-phenylacetophenone, 2-alkylthioxanthone, clotetrathioxanthone, 1-7enyl-1,2-propanedioxime, chlorinated acetophenone derivatives, etc. be able to.

The amount of these photoinitiators used is 0.01~
20wt, more preferably o, i~10w
It is t-.

When the curing means is radiation such as electron beams or R-rays, there is no particular need to use a photoinitiator because curing can be achieved quickly without the use of a photoinitiator.

EXAMPLES, COMPARATIVE EXAMPLES, AND REFERENCE EXAMPLES Next, the content of the present invention will be explained in more detail with reference to Examples and Comparative Examples. Note that the present invention is not limited to the examples.

Example 1 Tolylene diisocyanate (hereinafter referred to as T
(referred to as DI) 174 parts (parts by weight, same hereinafter), 67 parts of dimethylolpropionic acid (referred to as DMPA hereinafter),
10 parts of dibutyltin dilaurate, 895 parts of methyl isobutyl ketone (hereinafter referred to as MIBK), and 895 parts of toluene were charged and reacted at a reaction temperature of 90 to 100°C for 4 hours to obtain a terminal isocyanate acid diol adduct compound (A).

Next, 700 parts of Uniol D-700 (polypropylene glycol: molecular weight 700, manufactured by NOF ■) was added to this terminal isocyanate acid diol adduct compound.
The reaction was carried out at 60-80°C for 4 hours to obtain a carboxyl group-containing terminal hydroxyl group urethane oligomer (A).

Furthermore, TDI/2-hydroxyethyl acrylate adduct (hereinafter referred to as TDI/2-HEA adduct) is added to this carboxyl group-containing terminal hydroxyl group urethane arylate).
Add 290 parts of and react at 60-80°C for 4 hours,
A carboxyl group-containing urethane acrylate <1> having an acid value of 0.41 meq/g (solid content equivalent value) and a number average molecular weight of 31,000 was obtained.

The method for manufacturing the above TDI/2-HEA adduct is as follows. Into a 3L four-bottle flask equipped with a thermometer, reflux condenser, and stirrer, 870 parts of TDI, 15 parts of dibutyltin dilaurate, and 0.7 parts of hydroquinone monomethyl ether were charged, and while maintaining the reaction temperature at 60-70°C, 2- 580 parts of hydroxyethyl acrylate was added dropwise and heated and aged for an additional 2 hours to obtain TDI/
A 2-HEA adduct was obtained.

Example 2 In the same manner as in Example 1, 1174 parts of TD, DMP A
67 parts, dibutyltin silacrate 0.7 parts, MIBK
and 594 parts of toluene to obtain a terminal isocyanate diol acid adduct compound (A), and then 460 parts of Plaxel L-208AL (manufactured by Daicel Chemical Industries, Ltd.: Volicaprone lactone polyol) and LIR, I
198 parts of CH-62 (castor oil polyol: molecular weight 420, manufactured by Ito Oil Co., Ltd.) is added to obtain a carboxyl group-containing terminal hydroxyl group urethane oligomer (B).

Furthermore, 290 parts of TDI/2-HEA adduct (D) was added dropwise and reacted to form a urethane acrylate (2
) was obtained.

Example 6 1174 parts of TD, 67 parts of DMPA, 0.9 parts of digityltin silacrate, 700 parts of MIBK, and 700 parts of toluene
of the terminal isocyanate diol acid adduct compound (A).
I got it. Next, Plaxel L-208AL 87 was added to this terminal isocyanate diol acid adduct compound (A).
0 part was added and reacted at 70-90°C for 6 hours to obtain a carboxyl group-containing terminal hydroxyl group urethane oligomer (B). Furthermore, 191 parts of TDI was added to this carboxyl group-containing terminal hydroxyl group urethane oligomer (B), and the reaction temperature was 7.
The reaction was carried out at 0 to 90°C for 4 hours to obtain a carboxyl group-containing terminal isocyanate urethane IJ polymer (C). Finally, this carboxyl group-containing terminal isocyanate urethane oligomer (0.7 parts of QK hydroquinone monomethyl ether, 12 parts of 2-hydroxyethyl acrylate)
7 parts was added and the reaction was carried out for 5 hours at a reaction temperature of 60-80°C, acid value o, ssmeq/g (solid content equivalent value),
Urethane acrylate (3) having a number average molecular weight of 1860 was obtained.

Comparative Example 1 Using the same apparatus as in Example 1, 696 parts of TDI, DM
154 parts of PA, and 20 parts of polyethylene glycol Luna
When 200 parts of 0.0 was charged into a flask and the reaction was started at 60°C, temperature control was difficult and the reaction temperature rose to 120°C, resulting in gelation.

Comparative Example 2 Using the same apparatus as in Example 1, 348 parts of TDI, DM
P A 67 parts, Plaxel L-212AL 630 parts,
0.8 parts of dibutyltin silacrate, 634 parts of MIBK, and 664 parts of toluene were placed in a flask, and heated at 60°C for 7 hours.
A time reaction was carried out to obtain a terminal isocyanate prepolymer solution.

Next, 0.64 parts of hydroquinone monomethyl ether and 232 parts of 2-hydroxyethyl acrylate were added to this prepolymer solution and reacted at 60-80°C for 5 hours to give an acid value α of 59 meq/g (solid content equivalent value), A carboxyl group-containing urethane acrylate (4) having a number average molecular weight of 2,600 was obtained.

Reference Example Using a doctor blade with a gear opening of 200 μm, the carboxyl group-containing urethane acrylates +11 to (4) obtained in Examples and Comparative Examples were applied onto a polyester film base material, and the solvent was dried and removed with hot air. After that, E
Using an electrocurtain type electron beam irradiation device manufactured by SI,
The coating film was cured by irradiation with an electron beam of 10 Mrad at an accelerating voltage of 170 KV in a nitrogen atmosphere. The cured coating film was peeled off from the film base material, and the transparency and mechanical strength of the coating film were measured.

On the other hand, to the carboxyl group-containing urethane acrylates <1> to (4) obtained in Examples and Comparative Examples, a photoinitiator (Daruki Air 1173: manufactured by Merck Japan ■) was added in an amount of 5% by weight based on the solid content to form a coating composition. After preparing the product, coating it on a metal substrate using a bar coater 20, drying with hot air, curing with ultraviolet irradiation, and performing a peel test to determine the cured coating on the metal substrate. The adhesion to was investigated. For ultraviolet irradiation, UV-400 (for l,
Irradiation was performed once from a distance of 10 beams above the conveyor at a conveyor speed of 5 m/min.

These results are shown in Table 1.

Table 1 Also, using the carboxyl group-containing urethane acrylates <1> to (4) obtained in the Examples and Comparative Examples, a coating composition having the composition shown in Table 2 was prepared, and mixed and dispersed for 1 hour using a ball mill. Ta. Gap distance after mixing and dispersion: 200μm
Paint is applied onto a polyester base material using doctor grade, and after drying and removing the solvent with hot air, ESI is applied.
Electrocurtain electron beam irradiation device manufactured by Co., Ltd., acceleration voltage 170 KV, 10 Mrad f) Electron beam irradiation/
The coating film was cured by irradiation under a nitrogen atmosphere.

Table 3 shows the results of measuring the surface gloss of the obtained painted film.
It was shown to.

Table 2 Table 3 (c) Effects of the invention As shown in Table 1, the resin composition obtained by the invention has excellent mechanical properties of the coating film and adhesion to metal substrates, and is compatible with other materials. To provide a transparent film that does not have the disadvantages of clouding of a cured film or generation of grains due to separation. Furthermore, as shown in Table 6, metals and metal oxides are well dispersed.

The resin composition according to the present invention takes advantage of these characteristics and is particularly useful in fields that use electron beams, ultraviolet rays, etc. as curing means, such as paints, inks, conductive paints, etc.

Claims (1)

[Claims] 1. <1> A step of producing a terminal isocyanate diol adduct compound (A) from a polyvalent isocyanate and an acid diol, <2> A terminal isocyanate diol adduct compound (
Step of producing a carboxyl group-containing terminal hydroxyl group urethane oligomer (B) from A) and a polyhydric alcohol; C); and <4> producing a carboxyl group-containing urethane (meth)acrylate from a carboxyl group-containing terminal isocyanate urethane oligomer (C) and a hydroxyl group-containing (meth)acrylate. Or a method for producing a radiation-curable resin composition. 2, <1> Step of producing terminal isocyanate acid diol adduct compound (A) from polyvalent isocyanate and acid diol, <2> Terminal isocyanate acid diol adduct compound (
Step of manufacturing a carboxyl group-containing terminal hydroxyl group urethane oligomer (B) from A) and a polyhydric alcohol, <3> Manufacturing a terminal isocyanate (meth)acrylate adduct (D) from a polyvalent isocyanate and a hydroxyl group-containing (meth)acrylate. Step and <4> Carboxyl group-containing urethane (meth) from carboxyl group-containing terminal hydroxyl group urethane oligomer (B) and terminal isocyanate (meth)acrylate adduct (D)
A method for producing an ultraviolet or radiation-curable resin composition, comprising the steps of producing an acrylate.