JPH0730299B2 - Adhesive for radical polymerizable resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adhesive for radically polymerizable resin on various substrates, more specifically, it is applied on at least one surface of various substrates and has excellent adhesiveness to the radically polymerizable resin on the substrate. The present invention also relates to a water-soluble or water-dispersible heat-reactive urethane composition that imparts high-temperature and humidity blocking resistance.

Conventionally, as the radical polymerizable resin, there are a low molecular weight monomer type containing a polymerizable double bond or a triple bond and an intermediate molecular weight oligomer type, the curing mechanism of these resins has a radical polymerization mechanism, Thermal polymerization, in addition to radical polymerization by a radical initiator, ultraviolet curing, curing of an electron beam or the like in an extremely short period of time is possible, and in general, since solvent-free is aimed at, energy cost aspect, It is considered to be effective from the viewpoint of environmental pollution, and is expected to hold great promise for applications such as electronic materials, printing, and paints.

However, these radical-polymerizable resins have poor adhesiveness to various substrates, and at present the compound and means (processing method) for improving the adhesiveness of these resins to various substrates have not yet been established.

Therefore, the object of the present invention is to provide good adhesiveness between the radical-polymerizable resin and various substrates, and good adhesiveness for blocking properties under high temperature and high humidity, which is excellent as a primer coating agent. It is intended to provide a water-soluble or water-dispersible, heat-reactive urethane composition having excellent performance. That is, the present invention, by reacting a compound having two or more active hydrogens having an unsaturated polyester polyol and / or polybutadiene polyol and / or an acrylic polyol as an essential component with an organic polyisocyanate, a free isocyanate group is obtained, After forming a prepolymer having two or more, a blocking agent that regenerates an isocyanate group by heat treatment or a blocking agent that regenerates an isocyanate group by heat treatment, and one or more active hydrogens in the molecule, and a hydrophilic group A water-soluble or water-dispersible, heat-reactive urethane composition as a main component, which is obtained by reacting with a compound having a radical-polymerizable resin, is provided.

Next, the production of the water-soluble or water-dispersible, heat-reactive urethane composition used in the present invention will be described.

In the present invention, a compound having two or more active hydrogens containing an unsaturated polyester polyol and / or a polybutadiene polyol and / or an acrylic polyol as an essential component and a prepolymer having two or more free isocyanate groups by an organic polyisocyanate are provided. A water-soluble or water-dispersible, heat-reactive type reaction product obtained by reacting a blocking agent that regenerates an isocyanate group by heat treatment with a compound having one or more active hydrogens in the molecule and a hydrophilic group after production. A urethane composition is used.

The unsaturated polyester polyol is one having at least one ester bond and at least one double bond in one molecule, and examples thereof include unsaturated polycarboxylic acids such as maleic acid, fumaric acid and their anhydrides. Acids and their anhydrides and / or aromatic polyvalent carboxylic acids such as phthalic acid and isophthalic acid, and polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, hexylene glycol and trimethylolpropane And polycondensation products with unsaturated polyhydric alcohols such as butenediol.

Examples of the polybutadiene polyol include 1.2 polybutadiene polyol and 1.4 polybutadiene polyol. Examples of the acrylic polyol include acrylic polyols having a hydroxyl group in the side chain, which are obtained by copolymerization of various acrylic acid type monomers with hydroxyl group-containing acrylic acid type monomers such as hydroxyethyl acrylate and hydroxymethacrylate.

Examples of the compound having two or more active hydrogens include polyhydric alcohols exemplified in the above, which are usually used for urethane production, polyester polyols other than the unsaturated polyester polyols exemplified above, and alkylene oxide compounds such as ethylene oxide, propylene oxide and butylene oxide. Polyether polyols by addition, amino alcohols such as ethanolamine, diethanolamine, and triethanolamine, polyether polyols obtained by polyadding alkylene oxide to the amino alcohols, and the like. Any compound having two or more hydrogen atoms can be used.

The unsaturated polyester polyol, the polybutadiene polyol, and the acrylic polyol may be used alone or in combination.

On the other hand, the unsaturated polyester polyol, the polybutadiene polyol, the acrylic polyol, and the compound having two or more active hydrogens are used at a ratio of the finally obtained water-soluble or water-dispersible heat-reactive urethane composition of the present invention. Which affects the adhesiveness between the primer layer on the surface of various base materials obtained by applying and heat-treating various materials, and the radically polymerizable resin applied on the primer layer, and the unsaturated polyester polyol and / or polybutadiene polyol and / or ,
The higher the proportion of acrylic polyol is, the more preferable, that is, these polyols are essential, but some of the active hydrogen is 2%.
You may use together the compound which has more than one. These essential polyol components are preferably present in an amount of 10% by weight or more in all compounds having two or more active hydrogens in the starting materials including them.

Examples of the organic polyisocyanate include diphenylmethane diisocyanate, aromatic isocyanate such as toluene diisocyanate, aliphatic isocyanate such as hexamethylene diisocyanate, alicyclic isocyanate of isophorone diisocyanate, aromatic aliphatic isocyanate of xylylene diisocyanate, and the like. Examples thereof include polyisocyanates obtained by previously reacting an isocyanate with a low molecular weight polyol such as trimethylolpropane.

The reaction between the unsaturated polyester polyol and / or the polybutadiene polyol and / or the acrylic polyol and the compound having two or more active hydrogens and the organic polyisocyanate is carried out without solvent or under an organic solvent.

However, the preferred organic solvent is inert with isocyanate, and considering the distillation of the organic solvent in the final step,
It is preferable to dissolve in a hydrophilic organic solvent having a boiling point of 100 ° C. or lower or azeotropic with water at 100 ° C. or lower, and as the organic solvent, dioxane, acetone, tetrahydrofuran,
Examples thereof include ethyl acetate and methyl ethyl ketone.

The number of moles of the isocyanate group of the organic polyisocyanate and the unsaturated polyester polyol and / or the polybutadiene polyol and / or the acrylic polyol and the active hydrogen group of the compound having two or more active hydrogens is an excess of the isocyanate group. Can be set arbitrarily, but is preferably isocyanate group / active hydrogen group = 1.1 ~
It is preferably set in the range of 2.0. It should be noted that this step is carried out at room temperature to 100 ° C., and ordinary urethane catalysts such as organic acid, inorganic acid, metal and amine catalysts can be applied in this step.

Through the above steps, a prepolymer having two or more free isocyanate groups can be prepared. Next, a blocking agent that regenerates an isocyanate group by heat treatment will be exemplified.

Examples of these blocking agents include bisulfites such as sodium bisulfite, oximes such as butane oxime and cyclohexanone oxime, phenols such as phenol and alkylphenol, active methylene compounds such as acetylacetone, isopropyl alcohol and tert-butyl alcohol. Secondary and tertiary alcohols, imidazole, 4,5 or 2
Examples thereof include imidazoles such as position-substituted imidazole.

The reaction of these with the isocyanate group of the prepolymer having the free isocyanate group is carried out as follows. The bisulfite is added as a 10 to 35% aqueous solution, and in that case, it is preferably carried out in a hydrophilic solvent such as ethanol, isopropyl alcohol or ethyl cellosolve. Other oximes, phenols, active methylene compounds, secondary and tertiary alcohols, and imidazoles are reacted and carried out in a non-aqueous system at room temperature to 100 ° C, and if necessary, the above-mentioned usual urethanes are used. Chemical catalysts can be used. Further, if necessary, it can be carried out in the presence of an organic solvent such as dioxane, acetone, tetrahydrofuran, ethyl acetate, methyl ethyl ketone.

In the above blocking agent, the bisulfite can be used alone because it can impart water solubility or water dispersibility to the urethane prepolymer, but other phenols, oximes, active methylene compounds, second Since tertiary alcohols and imidazoles cannot impart water solubility or water dispersibility to urethane prepolymers, they are used in combination with a compound having at least one active hydrogen in the molecule and having a hydrophilic group. . The amount of the blocking agent that cannot impart water solubility or water dispersibility and the compound having one or more active hydrogens in the molecule and having a hydrophilic group is the free isocyanate group obtained in the above step. 50% by weight to 95% by weight of the isocyanate group of the prepolymer having the above is reacted with the blocking agent that cannot give water solubility or water dispersibility, and the remaining isocyanate group is reacted with one active hydrogen in the molecule. It is set so as to react with a compound having the above and having a hydrophilic group. If the ratio of the compound having one or more active hydrogens in the molecule and the hydrophilic group is higher than the above, the water resistance and the solvent resistance of the primer layer on the surface of various substrates processed by the compound will be poor. .

Examples of the compound having at least one active hydrogen in the molecule and having a water-soluble group or a hydrophilic group are classified into a monofunctional compound and a polyfunctional compound. Examples of monofunctional compounds include aminosulfonic acids such as taurine, N-methyltaurine, and sulfanilic acid, aminocarboxylic acids such as glycine and alanine, quaternized alcohols such as quaternary compounds of dimethylethanolamine, methanol, ethanol, and the like. The monofunctional polyethers obtained by polyadding ethylene oxide to the above monoalcohols, phenols, alkylphenols and other monophenols.

In addition, the urethane composition obtained by adding the amino alcohol is used in the same amount as the amino group or slightly in excess of the organic acid and / or
Alternatively, it is possible to impart hydrophilicity by neutralizing with an inorganic acid to form an amine salt. The above-mentioned aminosulfonic acids and aminocarboxylic acids are used in the reaction with the isocyanate group after making them water-soluble soda salt, potassium salt and triethylamine salt, and the addition reaction is carried out in the range of 30 to 50 ° C. The above quaternized alcohols and monofunctional polyethers are subjected to addition reaction with isocyanate groups in the range of room temperature to 100 ° C. and in a non-aqueous system.

Next, polyfunctional compounds include polyhydroxycarboxylic acids such as dimethylolpropionic acid, quaternized monomethyldiethanolamine, quaternized amino alcohols such as quaternized triethanolamine, and poly (ethylene oxide) polyadducts. Examples include ether polyols. Further, it is also possible to impart hydrophilicity by neutralizing the urethane composition formed by adding the amino alcohol with an organic acid and / or an inorganic acid in the same amount as or a slight excess of the amino group to form an amine salt. .

In these reactions, addition reaction with an isocyanate group is carried out in the range of room temperature to 100 ° C. and in a non-aqueous system. In addition,
These polyfunctional compounds may be reacted simultaneously with the preparation of the prepolymer having a free isocyanate group in the first step, or may be reacted with isocyanate after the preparation of the prepolymer, that is, before the reaction of the blocking agent. good.

In the above-mentioned dimethylolpropionic acid, after the completion of the previous step, it is converted into a water-soluble group or a hydrophilic group as a soda salt, potassium salt, or triethylamine salt.

Especially when the base used is triethylamine, the state of the carboxyl group volatilizes during the heat treatment, that is, it does not take a salt form, or the reaction between the carboxyl group and the regenerated isocyanate group causes the disappearance of the hydrophilic group, It is particularly preferable for improving the water resistance of the urethane composition.

After the above reaction, the water-soluble or water-dispersible heat-reactive urethane composition of the present invention can be produced by diluting with water.

Further, preferably, after the reaction or the dilution with water, the organic solvent used can be distilled off by distillation under normal pressure, preferably under reduced pressure.

The water-soluble or water-dispersible heat-reactive urethane composition thus obtained includes various plastics such as vinyl chloride, polyolefin, polystyrene, and polyurethane, or rubbers, metals such as aluminum and iron, and woods and papers such as glass. By coating a part or all of the surface of various base materials, pre-drying, and further heat-treating, it is possible to impart adhesiveness to the radical polymerizable resin to the various base materials. The heat treatment temperature is 100 to 230 ° C.

By this heat treatment, it is considered that the three-dimensional crosslinked structure and the urethane bond generated by the reaction of the urethane composition of the present invention act to improve the adhesiveness to the adherend. Since the isocyanate group is regenerated and cross-linked and polymerized, the obtained primer layer has good water resistance, and good blocking property under high temperature and high humidity.

The improvement of the adhesiveness with the radical polymerizable resin is achieved by crosslinking the polymerizable polyester double bond contained in the unsaturated polyester and polybutadiene in the urethane composition of the present invention with the double bond of the radical polymerizable resin and the urethane composition of the present invention. It is considered that this is due to the affinity between the acrylic polyol component in the product and the radically polymerizable resin.

In the present invention, the water-soluble or water-dispersible heat-reactive urethane composition has an acrylic acid-based polymer emulsion to the extent that it does not affect the water resistance of the primer layer to be obtained, the blocking property under high temperature and high humidity. It is also possible to blend and use, and in this case, it is preferable to blend an acrylic acid ester-based polymer emulsion having a functional group that reacts with an isocyanate group regenerated by heat treatment of the urethane composition of the present invention, for example, a hydroxyl group.

Next, the present invention will be specifically described with reference to examples and effects.

(Note that parts and% are based on weight.) Example 1 (Synthesis Example 1) Polybutadiene polyol 70 parts (molecular weight 2000), polyether polyol 30 parts (ethylene oxide polyaddition product /
(Molecular weight 2000) 16.8 parts of hexamethylene diisocyanate was added at a system temperature of 60 ° C, and the reaction was carried out at a system temperature of 95 ° C for 90 minutes to obtain 3.60% free isocyanate groups (polybutadiene polyol, polyether polyol, hexamethylene diisocyanate total To a urethane prepolymer having

Next, after adding 50 parts of methyl ethyl ketone, 3.30 parts of dimethylolpropionic acid was added, and the system temperature was kept at 75 ° C.
The reaction was carried out for 180 minutes to obtain a urethane prepolymer having 1.8% of free isocyanate groups (based on the total sum of polybutadiene polyol, polyether polyol, hexamethylene diisocyanate and dimethylol propionic acid).

Next, 4.4 parts of butanone oxime was added and the reaction was carried out at 60 ° C., and after confirming that the isocyanate group had completely disappeared, 2.49 parts of triethylamine were added, followed by dilution with water to obtain a solid content of 15%. A milky white heat-reactive urethane composition was obtained.

Next, at 60 ° C / 100mmHg, the water-methylethylketone mixed solvent of twice the amount of the used methylethylketone was distilled off over 180 minutes, and after confirming that the odor of methylethylketone disappeared in the system, it was corrected with water. Then, the solid content was set to 15%.

Example 2 (Synthesis Example 2) 70 parts of a polyester polyol (molecular weight 1000) composed of maleic anhydride and 1.6 hexanediol, 30 parts of a polyether polyol (ethylene oxide polyadduct. Molecular weight 2000) and 3.0 parts of trimethylolpropane were prepared. System temperature 60
Add 40.4 parts of hexamethylene diisocyanate at ℃, react for 60 minutes at the system temperature of 85 ℃, free isocyanate 6.20% (polyester polyol, polyether polyol, trimethylol propane, total hexamethylene diisocyanate) A urethane prepolymer having the above was obtained.

Next, after adding 50 parts of ethanol at a system temperature of 50 ° C, 147 parts of a 15% concentration sodium bisulfite aqueous solution was added at a system temperature of 35 ° C, and the reaction was performed at the same temperature for 90 minutes. After
It was diluted with water to obtain a transparent heat-reactive urethane composition having a solid content of 20%.

Next, after distilling off the water-ethanol mixed solvent of twice the amount of ethanol used at 50 ° C / 10mmHg for 180 minutes, it was confirmed that there was no odor of ethanol.
20%.

Example 3 (Synthesis Example 3) 100 parts of acrylic polyol (Acridic A-801, solid content 49.5%, OHV46.0, butyl acetate solution; Dainippon Ink and Chemicals, Inc.), polyether polyol 30 parts (ethylene oxide polyaddition) 23.26 parts of hexamethylene diisocyanate is added to the body (molecular weight: 1000), and the system temperature is 90 ° C.
A partial reaction was performed to obtain a urethane prepolymer having 3.70% of free isocyanate groups (based on the total of acrylic polyol, polyether polyol, and hexamethylene diisocyanate).

Next, add 4.30 parts of dimethylolpropionic acid, and add 90 ° C.
For 180 minutes, free isocyanate 1.85%
A urethane prepolymer having (based on the sum of acrylic polyol, polyether polyol, hexamethylene diisocyanate, and dimethylolpropionic acid) was obtained.

Next, 6.20 parts of methyl ethyl ketoxime was added and the reaction was carried out at 60 ° C. to completely eliminate the isocyanate group.

Next, it took 180 minutes at 90 ° C / 20mmHg to distill off the butyl acetate in the system, add 3.30 parts of triethylamine, and then dilute with water. Solid content 15%, translucent, heat-reactive urethane composition I got a thing.

Example 4 (Synthesis Example 4) To 30 parts of the polyester polyol used in Example 2 (Synthesis Example 2) and 30 parts of polyether polyol (ethylene oxide polyadduct. Molecular weight 1000), 33.1 parts of 2.4-toluene diisocyanate was added. Then, the reaction was carried out at an internal temperature of 70 ° C. for 60 minutes to obtain a blocked urethane prepolymer having 5.65% of free isocyanate groups (based on the total amount of polyester polyol, polyether polyol and 2.4-toluene diisocyanate).

Next, 7.90 parts of methyl ethyl ketoxime was added, and the reaction was carried out at 60 ° C for 60 minutes to obtain 2.80% of free isocyanate groups (polyester polyol, polyether polyol, 2,4
A blocked urethane prepolymer having (based on the total toluene diisocyanate) was obtained.

Next, 100 parts of methyl ethyl ketone and 2.97 parts of dimethylolpropionic acid were added, and the reaction was carried out at a system internal temperature of 70 ° C. to completely eliminate the isocyanate group, then 2.24 parts of triethylamine was added, and then diluted with water, Solid content 15%
To obtain a white heat-reactive urethane composition.

Next, it took 180 minutes under 60 ° C./100 mmHg to distill away the water-ethylketone mixed solvent in an amount twice the amount of methylethylketone in the system, and after confirming that the system did not smell of methylethylketone, correct with water, The solid content was 15%.

Effect Examples 1 to 4 The urethane compositions obtained in Examples 1 to 4 were tested according to the following test methods, and the results are shown in Table 1.

Adhesiveness: The urethane composition of the present invention obtained in Examples 1 to 4 was applied to a glass plate and heat-cured (air-dried overnight → heat treatment 150 ° C. × 1).
Morohoshi Ink Co., Ltd. was applied to the glass plate obtained by performing the treatment for 0 minutes. UV-curable ink (UVS-PCD-Red T) is printed to a thickness of 4μ, and UV irradiation device (ASE-2 manufactured by Nippon Battery Co., Ltd.)
It was cured at a strength of 80 (w / cm) and a speed of 3 (m / min).

Next, scotch tape No600 (3M, width 19.4 mm) was adhered so that air bubbles did not enter, and the top of this was JIS-C2701 (19
Use a manual load roll as described in 75) and level it in close contact. Further, the non-adhesive both ends of this sample were held by both hands, and the peeling condition of the ultraviolet curable ink after rapid peeling was observed and evaluated according to the following criteria.

(Evaluation Criteria) x: Almost all of the UV curable ink was transferred to the adhesive tape. Δ: Half of the UV curable ink remained on the glass plate. ○: All of the UV curable ink remained on the glass plate. Examples 1 to 4 correspond to Examples 1 to 4. The untreated glass plate is obtained by applying the above ultraviolet curable ink to an untreated glass plate and curing it.

Claims (1)

[Claims] 1. A free isocyanate group having two free isocyanate groups by reacting an organic polyisocyanate with a compound having two or more active hydrogens containing an unsaturated polyester polyol and / or a polybutadiene polyol and / or an acrylic polyol as an essential component. A water-soluble or water-dispersion product obtained by reacting a prepolymer having the above with a blocking agent that regenerates an isocyanate group by heat treatment and a compound having one or more active hydrogens in the molecule and having a hydrophilic group An adhesive for radically polymerizable resins, which comprises a heat-curable urethane composition as a main component.