JP5068513B2 - Unsaturated group-containing urethane resin and active energy ray-curable resin composition containing the same - Google Patents

Description

  The present invention relates to an unsaturated group-containing urethane resin suitably used for, for example, inks, paints, adhesives, and the like, and an active energy ray-curable resin composition containing the same.

Since unsaturated group-containing urethane resins are rich in flexibility and can form a tough cured film, they are widely used as active energy ray-curable resins, such as inks, paints, and adhesives (for example, (See Patent Document 1).
The unsaturated group-containing urethane resin is usually obtained by reacting a polyol component such as polyester polyol, polyether polyol or polycarbonate diol, a diisocyanate component, and a radical polymerizable hydroxyl group-containing unsaturated monomer component. In this structure, a repeating unit composed of a polyol component and a diisocyanate component is used as a resin skeleton, and a radical polymerizable hydroxyl group-containing unsaturated monomer component is bonded to the terminal of the resin skeleton.
JP 2003-40965 A

  However, in order to improve the flexibility and elongation of the cured film to be formed, when the resin skeleton composed of the above-mentioned repeating units is increased in molecular weight, the terminal hydroxyl group-containing unsaturated monomer component in the unsaturated group-containing urethane resin Content (unsaturation degree) will fall relatively. When the degree of unsaturation decreases, the curing performance tends to deteriorate, such as the decrease in the curing rate of the unsaturated group-containing urethane resin and the decrease in the surface hardness and contamination resistance of the cured film due to insufficient crosslinking density. there were.

  The present invention has been made in view of the above circumstances, and has an unsaturated group-containing urethane resin having sufficient curing performance and excellent flexibility and elongation of a formed cured film, and an active energy ray-curable resin composition including the same. The issue is to provide goods.

As a result of intensive studies, the present inventor has selected a polycarbonate diol (a) that imparts flexibility and elongation to the cured film as a component to be reacted with the polyisocyanate (c), and two hydroxyl groups and two hydroxyl groups. By using a bifunctional epoxy (meth) acrylate (b) containing an ethylenically unsaturated group, it is conceived that a cured film having good flexibility and elongation can be formed without deteriorating the curing performance. The invention has been completed.
The unsaturated group-containing urethane resin of the present invention includes a polycarbonate diol (a), a bifunctional epoxy (meth) acrylate (b) containing two hydroxyl groups and two ethylenically unsaturated groups in the molecule, It is characterized by reacting only polyisocyanate (c).
The number average molecular weight of the polycarbonate diol (a) is preferably 500 to 3,000.
The unsaturated group-containing urethane resin of the present invention preferably has a number average molecular weight of 1,000 to 100,000 and an unsaturation degree of 0.1 to 1 mol / kg.
The active energy ray-curable resin composition of the present invention is characterized in that 0.1 to 15 parts by mass of a photopolymerization initiator is blended with 100 parts by mass of the unsaturated group-containing urethane resin.

  ADVANTAGE OF THE INVENTION According to this invention, while providing sufficient hardening performance, the softness | flexibility of the cured film formed and the unsaturated group containing urethane resin which is excellent in elongation, and the active energy ray hardening-type resin composition containing this can be provided.

Hereinafter, the present invention will be described in detail.
The unsaturated group-containing urethane resin of the present invention contains a polycarbonate diol (a) (hereinafter sometimes referred to as component (a)), and two hydroxyl groups and two ethylenically unsaturated groups in the molecule. A reaction between a bifunctional epoxy (meth) acrylate (b) (hereinafter also referred to as component (b)) and polyisocyanate (c) (hereinafter also referred to as component (c)) It is.

  The polycarbonate diol (a) has a polymer chain in which a hydrocarbon group derived from a polyol is connected via a carbonate bond, and a hydroxyl group bonded to both ends of the polymer chain. The thing of the structure of (a-1) is mentioned.

  Although there is no restriction | limiting in particular in the value of l, m, n in Formula (a-1), since it is preferable that the polycarbonate diol (a) is 500-3000, such a number average molecular weight and It is preferable that If the number average molecular weight of the polycarbonate diol (a) to be used is less than this range, the cured film formed may have poor flexibility and elongation, and if this range is exceeded, the crystallinity of the polycarbonate diol (a) may be reduced. Since it becomes strong and its viscosity increases, handling in manufacturing may be difficult.

In addition, the value of 1 and m in Formula (a-1) is an integer determined by the kind of polyol used as a raw material, Comprising: As a polyol, it has a C2-C10 linear and side chain. Diols are mentioned. Specifically, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2-methyl-1,8-octanediol, 1,4-cyclohexanedimethanol, etc. Of these, two or more of them may be used in combination. Of these, polycarbonate diols with 1,5-pentanediol and / or 1,6-hexanediol are preferred.
Moreover, as a component (a), 1 type of compounds may be used independently and 2 or more types may be used together.

  The bifunctional epoxy (meth) acrylate (b) containing two hydroxyl groups and two ethylenically unsaturated groups in the molecule is, for example, a compound represented by the following formula (b-2). Specifically, (meth) acrylic acid addition product of propylene glycol diglycidyl ether, (meth) acrylic acid addition product of 1,6 hexanediol diglycidyl ether, (meth) acrylic acid addition of ethylene glycol diglycidyl ether 1,4-Butanediol diglycidyl ether (meth) acrylic acid adduct, 1,5-pentanediol diglycidyl ether (meth) acrylic acid adduct, 1,7-heptanediol diglycidyl ether (meth ) Acrylic acid adduct, 1,8-octanediol diglycidyl ether (meth) acrylic acid adduct, etc. It is. In addition, (meth) acrylic acid adduct of neopentyl glycol diglycidyl ether, (meth) acrylic acid adduct of bisphenol A diglycidyl ether, (meth) acrylic acid adduct of hydrogenated bisphenol A diglycidyl ether Etc. Among these, an acrylic acid adduct of propylene glycol diglycidyl ether and an acrylic acid adduct of 1,6 hexanediol diglycidyl ether are preferable.

In formula (b-1), p is an integer, preferably 2-6.
As the component (b), one type of compound may be used alone, or two or more types may be used in combination.

  Although there is no restriction | limiting in particular as polyisocyanate (c), For example, diisocyanate compounds, such as an aliphatic diisocyanate compound, an alicyclic diisocyanate compound, and an aromatic diisocyanate compound, can be used preferably. Specifically, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) -diisocyanate, 1,3- (isocyanatomethyl) cyclohexane, isophorone diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, dianisidine diisocyanate, phenyl diisocyanate, halogenated phenyl diisocyanate, methylene diisocyanate, ethylene diisocyanate, butylene diisocyanate, Propylene diisocyanate, octadecile Diisocyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenylene diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, tolylene diisocyanate polymer, polymer of diphenylmethane diisocyanate, polymer of hexamethylene diisocyanate, 3-phenyl-2-ethylene diisocyanate , Cumene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-ethoxy-1,3-phenylene diisocyanate, 2,4′-diisocyanate diphenyl ether, 5,6-dimethyl-1,3-phenylene Diisocyanate, 4,4'-diisocyanate diphenyl ether, benzidine diisocyanate, 9,10-anthracene diisocyanate 4,4'-diisocyanate benzyl, 3,3'-dimethyl-4,4'-diisocyanate diphenylmethane, 2,6-dimethyl-4,4'-diisocyanate diphenyl, 3,3'-dimethoxy-4,4 ' -Diisocyanate diphenyl, 1,4-anthracene diisocyanate, phenylene diisocyanate, 2,4,6-tolylene triisocyanate, 2,4,4'-triisocyanate diphenyl ether, 1,4-tetramethylene diisocyanate, 1,6-hexa Examples include methylene diisocyanate, 1,10-decamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, and 4,4′-methylene-bis (cyclohexyl isocyanate).

In addition, as component (c), triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene, 4,4 Polyisocyanate compounds having three or more isocyanate groups such as '-dimethyldiphenylmethane-2,2', 5,5'-tetraisocyanate; ethylene glycol, propylene glycol, 1,4-butylene glycol, polyalkylene glycol, Addition products obtained by reacting an excess amount of a polyisocyanate compound with respect to the hydroxyl group of a polyol such as trimethylolpropane or hexanetriol; hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate 4 , 4′-diphenylmethane diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate) and other burette type adducts, isocyanuric ring type adducts, and the like can also be used.
As these (c) components, one type of compound may be used independently and 2 or more types may be used together.

According to the unsaturated group-containing urethane resin obtained by reacting the components (a) to (c) described above, as the component to be reacted with the component (c), the above-mentioned polycarbonate diol (a) and two hydroxyl groups in the molecule And a bifunctional epoxy (meth) acrylate (b) containing two ethylenically unsaturated groups. Therefore, while providing sufficient curing performance derived from the component (b), a cured film having excellent flexibility and elongation derived from the component (a) can be formed.
Here, when only the component (b) is used as the component to be reacted with the component (c), the obtained unsaturated group-containing urethane resin has a high degree of unsaturation derived from the component (b). Therefore, the curing performance tends to be excellent. However, the formed cured film has insufficient flexibility and elongation, and the film performance is not good. In addition, when only the component (a) is used as the component to be reacted with the component (c), the unsaturated group-containing urethane resin does not contain the unsaturated group derived from the component (b), so that the curing itself is not performed. It becomes difficult. When a diol other than polycarbonate diol is used instead of component (a), or when bifunctional epoxy (meth) acrylate that does not contain two hydroxyl groups is used instead of component (b) However, the curing performance is insufficient.

The unsaturated group-containing urethane resin of the present invention preferably has a number average molecular weight of 1,000 to 100,000 and an unsaturation degree of 0.1 to 1 mol / kg. If the number average molecular weight is less than the above range, the flexibility and elongation of the cured film to be formed tend to be insufficient, and if it exceeds the above range, the crystallinity and the viscosity become very high, making it difficult to ensure production stability. Tend. Further, if the degree of unsaturation is less than the above range, the curing performance tends to be insufficient, or the crosslinking density of the formed cured film tends to be small, and sufficient surface curability tends to be obtained, which exceeds the above range. And sufficient surface curability can be obtained, but the cured film tends to be hard and less flexible and stretchable. A more preferred number average molecular weight is 10,000 to 50,000, and an unsaturation degree is 0.1 to 0.5 mol / kg.
The degree of unsaturation means that the number of moles of component (b) necessary for producing 1 kg of resin is α mol, and the number of radical polymerizable unsaturated bonds contained in one molecule of component (b) is β. In this case, the value is calculated by α × β.

The unsaturated group-containing urethane resin of the present invention can be produced by introducing the above-described components (a) to (c) into an organic solvent and reacting them.
The reaction temperature is usually 20 to 250 ° C, preferably 50 to 150 ° C. Further, the reaction may be carried out as appropriate until the isocyanate residue disappears, and the reaction time is usually 10 minutes to 24 hours. As the organic solvent, for example, various solvents such as hydrocarbon, ketone, ether and ester can be used. Further, during the reaction, a reaction catalyst of an isocyanate group and a hydroxyl group can be added as necessary. Examples of such a reaction catalyst include lead oleate, tetrabutyltin, antimony trichloride, triphenylaluminum, and trioctylaluminum. , Zinc naphthenate, zirconium naphthenate, dibutyltin dilaurate, tetra-n-butyl-1,3-diacetyloxydistanoxane, 1,4-diaza [2,2,2] bicyclooctane, N-ethylmorpholine, etc. be able to.

The ratio of the component (a), the component (b), and the component (c) may be determined according to the degree of unsaturation and the number average molecular weight required for the unsaturated group-containing urethane resin. Is 1000 to 100,000, and in order to produce an unsaturated group-containing urethane resin having an unsaturation degree of 0.1 to 1 mol / kg, the total measurement (solid content) of the components (a) to (c) is 100% by mass. It is preferable that (a) component is 60-90 mass%, (b) component is 2.5-15 mass%, and (c) component is 5-25 mass%.
Moreover, when using a reaction catalyst, it is normally used in 0.005-0.5 mass part with respect to 100 mass parts of total measurement (solid content) of (a)-(c) component.

The active energy ray-curable resin composition (hereinafter referred to as a resin composition) of the present invention contains 0.1 to 15 parts by mass of a photopolymerization initiator with respect to 100 parts by mass of the unsaturated group-containing urethane resin. Can be obtained. In addition, since this resin composition is usually applied to an object as ink, paint, adhesive, etc., an appropriate amount of an organic solvent as exemplified above is used from the viewpoints of applicability, handleability, and the like. You may contain.
Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1- Hydroxycyclohexyl-phenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone, 2,4,6 -Trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, benzophenone, methyl o-benzoylbenzoate, hydroxybenzophenone, 2-isopropylthioxan 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 2,4,6-tris (trichloromethyl) -S-triazine, 2-methyl-4,6-bis (trichloro ) -S-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine, iron-allene complex, titanocene compound, etc., and one or more of these can be used. .

  A sensitizing dye may be used in combination with the photopolymerization initiator in the resin composition. If necessary, dyes, pigments, various additives (polymerization inhibitors, leveling agents, antifoaming agents, sagging inhibitors, adhesion improvers, coating surface modifiers, plasticizers, nitrogen-containing compounds, etc.), crosslinking An agent (such as an epoxy resin) may be included.

Such resin compositions include, for example, paints, inks, adhesives, etching resist materials, solder resist materials, plating resist materials, photovia build-up insulating materials, printing plate materials (plate and letterpress plate making materials, PS for offset printing) Plate) can be used for information recording materials, relief image forming materials, optical fiber coating materials, and the like.
When the resin composition is applied to an object, spray coating, electrostatic coating, spin coating, dip coating, roller coating, curtain flow coating, silk printing, or the like may be used. Moreover, there is no restriction | limiting in particular in the film thickness in that case, Usually, it is 0.5-100 micrometers, Preferably it is 1-50 micrometers.
There is no restriction | limiting in particular in the active energy ray which hardens a resin composition, For example, an ultraviolet-ray, visible light, a laser beam (near infrared rays, visible light laser, an ultraviolet laser etc.) is mentioned, The irradiation amount is 0.2 ~ normally. It is 2,000 mJ / cm ² , preferably 1 to 1,000 mJ / cm ² .

Hereinafter, the present invention will be specifically described with reference to examples.
[Example 1]
As shown in Table 1, a polycarbonate diol of 1,5-pentanediol and 1,6-hexanediol (PCDL T-manufactured by Asahi Kasei Chemicals Corporation) was added to a 1 L four-necked flask equipped with a thermometer, a condenser, and a stirrer. 5652, number average molecular weight: 2000) 341 g, 1,6-hexanediol diglycidyl ether acrylic acid adduct (Showa Polymers Lipoxy SP-16LDA) 17 g, isophorone diisocyanate 43 g, dibutyltin dilaurate (reaction catalyst) 0.2 g and 400 g of methyl ethyl ketone (organic solvent) were added, and the mixture was stirred at 70 ° C. for about 24 hours to be reacted. After the reaction, it was confirmed by the infrared absorption spectrum that no isocyanate residue was observed.
Thus, the resin liquid which contains 50 mass% of unsaturated group containing urethane resins of the number average molecular weight 30000 and unsaturation degree 0.23 mol / kg as solid content was obtained.
Next, 1.5 parts by mass of a photopolymerization initiator (Irgacure 184, 1-hydroxycyclohexyl-phenylketone manufactured by Ciba Specialty Chemicals Co., Ltd.) with respect to 100 parts by mass of the unsaturated group-containing urethane resin (solid content) in the resin liquid. ) Was prepared, and this resin composition was coated on a glass plate with a film thickness of about 100 μm. Thereafter, the film was allowed to stand at 40 ° C. for 24 hours to completely volatilize methyl ethyl ketone, and then irradiated with ultraviolet rays at 100 mJ / cm ² to form a cured film. And about this cured film, surface curability (finger touch comparison), a softness | flexibility, and elongation were evaluated by the following method. The results are shown in Table 1.

<Evaluation method>
(1) Surface curing property It implemented by the finger touch evaluation which touches the surface of a cured film with a finger, and evaluated in three steps.
The case where no tack was recognized was shown in the table as “◯”, the case where tack was clearly recognized as “x”, and the feel between them as “Δ”.
(2) Flexibility About the cured film peeled off from the glass plate, 180 degree folding was repeated, and when the number of folding was 3 times or less, cracks or cracks occurred in the case of “X”, and when the crack occurred in 4 to 10 times. A case where no cracks or cracks were generated even after being bent 10 times was shown as “◯” in the table.
(3) Elongation Performed according to the test method of JIS K6251 “Method of obtaining tensile properties of vulcanized rubber and thermoplastic rubber”, “x” when the elongation is 200% or less, “△” when 200 to 300%. The case of 300% or more is shown in the table as “◯”.

[Examples 2 to 5 and Comparative Examples 1 to 4]
A resin solution was prepared in the same manner as in Example 1 except that the types and masses of components to be charged into a 1 L four-necked flask equipped with a thermometer, a condenser, and a stirring device were changed as shown in Table 1. A cured film was formed and evaluated. In Examples 4 and 5 and Comparative Examples 2 to 4, the reaction temperature was set to 80 ° C. instead of 70 ° C. The results are shown in Table 1.

The details of each component in the table are as follows.
Polycarbonate diol (1): Polycarbonate diol of 1,5-pentanediol and 1,6-hexanediol (PCDL T-5562 manufactured by Asahi Kasei Chemicals Corporation, number average molecular weight: 2000)
Polycarbonate diol (2): 1,6-hexanediol polycarbonate diol (Nipporan N-980R, number average molecular weight: 2000, manufactured by Nippon Polyurethane)
Polycarbonate diol (3): Polycarbonate diol of 1,5-pentanediol and 1,6-hexanediol (PCDL T-5650J, manufactured by Asahi Kasei Chemicals Corporation, number average molecular weight: 800)
Polycaprolactone diol: PCL-220N manufactured by Daicel Chemical Industries, number average molecular weight 2000
Acrylic acid adduct of 1,6-hexanediol glycidyl ether: Lipoxy SP-16LDA manufactured by Showa Polymer Co., Ltd.
Acrylic acid adduct of propylene glycol diglycidyl ether: epoxy ester 70PA manufactured by Kyoeisha Chemical Co., Ltd.
Acrylic acid adduct of glycidyl methacrylate: NK ester 701A manufactured by Shin-Nakamura Chemical Co., Ltd.

As is apparent from Table 1, as the component to be reacted with the component (c), a polycarbonate diol (a) and a bifunctional epoxy (meta) containing two hydroxyl groups and two ethylenically unsaturated groups in the molecule. ) The unsaturated group-containing urethane resin of each example used in combination with acrylate (b) was able to form a cured film having sufficient curing performance and excellent in flexibility and elongation.

Claims (4)

Only the polyisocyanate (c) was reacted with the polycarbonate diol (a), the bifunctional epoxy (meth) acrylate (b) containing two hydroxyl groups and two ethylenically unsaturated groups in the molecule. Unsaturated group-containing urethane resin.   The number average molecular weight of the said polycarbonate diol (a) is 500-3000, The unsaturated group containing urethane resin of Claim 1 characterized by the above-mentioned.   3. The unsaturated group-containing urethane resin according to claim 1, wherein the number average molecular weight is 1000 to 100,000 and the degree of unsaturation is 0.1 to 1 mol / kg.   An active energy ray-curable resin composition comprising 0.1 to 15 parts by mass of a photopolymerization initiator based on 100 parts by mass of the unsaturated group-containing urethane resin according to any one of claims 1 to 3. object.