JPS5850620B2 - Method for manufacturing curable resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a resin that is cured by energy beams such as electron beams, particularly ultraviolet rays, visible light, or radical generators.

Recently, the development of resins that are cured by ultraviolet light has been attracting attention.

That is, it is a 100% solvent-free cured product, and due to its fast curing properties, it is expected to occupy the field of paints and inks in the future for the purpose of preventing air pollution and saving energy.

The development of resins for this purpose is also very active.
Many types of these resins have appeared, including unsaturated polyester resins, unsaturated polyethers, epoxy-acrylates, polyester-acrylates, and unsaturated acrylic-urethanes.

Each of these photocurable resins has its own characteristics and is useful for inks and paints.

However, the fact that there are currently some problems with photocurable resins is unavoidable because the development of this type of resin is still new.

The main problems are that as the thickness of the paint film increases, the curability deteriorates rapidly and it takes a long time to harden, and depending on the type of resin, it may not harden internally, especially if pigments are added to the surface. The chisel may stop curing and wrinkles may appear.

Other drawbacks include insufficient adhesion between the coating film and the substrate, and the difficulty of satisfying high surface hardness requirements, which can be fatal depending on the application.

Therefore, the present invention relates to a method for producing a photocurable resin that cures quickly to the inside and exhibits sufficient surface hardness even if the coating is thick.

Originally, the skeleton of a photocurable resin has two or more acryloyl groups or methacryloyl groups at the terminal or side chain of the molecule, and the molecular skeleton is polyester, polyether, epoxy resin, or polyurethane.

Generally speaking, polyester-acrylate and polyether-acrylate cannot be said to have a sufficient photocuring speed, while epoxy-acrylate can be said to have an adequate curing speed and coating hardness, but it is difficult to coat thickly. The disadvantage is that it lacks adhesion to the base material.

Also, the polyurethane type has problems with the storage stability of the resin,
As with other unsaturated acrylics, the hardness of both ester and ether bases is not sufficient, and when hardened they tend to impair adhesion.

Since unsaturated polyurethane appeared to have the best curing properties, we conducted repeated studies with the aim of obtaining a resin that combines the advantages of unsaturated polyurethane with the advantages of epoxy-acrylate. We have discovered that the objective can be achieved by using polyether or polyester having a cycloacetic structure as a polyhydric hydroxyl compound that is a component of polyurethane,
☆・The present invention has been completed.

In the present invention, as a component of the N polyhydric hydroxyl compound,
A polyhydric hydroxyl prepolymer obtained by the reaction of (1) an unsaturated cycloacetal and (ii) at least one of polyhydric alcohols, polyesters, and polyethers having two or more hydroxyl groups in one molecule. , (8
) A method for producing a resin curable by energy rays or a radical generator by reacting with an unsaturated urethane compound obtained by reacting the polyvalent incyanate (1) of (1) with a hydroxy unsaturated compound (2) as a linking agent. It is in.

To aid in understanding, an example of the present invention is illustrated by the following formula.

An extremely wide variety of unsaturated polyurethanes containing a cycloacetal structure according to the present invention can be synthesized by changing the type and amount of the polyvalent hydroxyl compound used, the type of isocyanate, etc.

The cycloacetal structure has toughness rather than rigidity in the benzene nucleus, is harder than an aliphatic ether bond, and has excellent adhesion, so it has extremely desirable properties as a polymer component for paints. ing.

In summary, unsaturated polyurethane, which has a cycloacecool structure in its molecule, has desirable properties such as high surface hardness, toughness of the coating film, and good adhesion to the substrate, while maintaining excellent photocurability. It has properties.

An unsaturated cycloacetal obtained by a condensation reaction between an α-β unsaturated aldehyde and a polyhydric alcohol is convenient as a raw material compound for introducing the cycloacecool structure applied to the present invention. is sufficient.

Its types include, for example, diarylidene pentaerythritol and triarylidene rubitol.

Hydroxy unsaturated cycloacetals that share a hydroxyl group and an unsaturated bond, such as monoallylidene trimethylolpropane, monoallylidene hexanetriol, monoallylidene glycerin, and monoallylidene trimethylolethane, also have their hydroxyl group expressed by the following formula: It can be used in the present invention by performing reactions such as esterification and transesterification as shown in FIG.

Polyhydric hydroxyl compounds for reacting with unsaturated cycloacetals to form polyethers containing a cycloacetal structure include (:) polyhydric alcohols, (11) polyhydroxy polyesters, and (iii) polyhydroxy polyethers.

Examples of polyhydric alcohols used as raw materials include ethylene glycol, diethylene glycol: 7-/L/,
) +) Ethylene glycol, propylene glycol,
Dipropylene glycol, ■・3-butanediol, 1
・4-butanediol, neopentyl glycol, 2.
2,4-trimethylpentanediolu 1,3,■,6
-hexanediol, ■・4-cyclohexane dimetatool, hydrogenated bisphenol A1, bisphenol A and ethylene oxide adduct, bisphenol A and propylene oxide adduct, dibromneopentyl glycol, trimethylolfuropane, trimethylolethane, Glycerin, pentaerythritol, and sorbitol can be mentioned.

Among the raw material components constituting polyester, the proportion of polyhydric alcohol is the same as in the previous example, but examples of acid components are as follows.

Phthalic anhydride, isophthalic acid, terephthalic acid and its methyl ester, succinic acid, adipic acid, sebacic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride,
Methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, Hett's acid, trimellidic anhydride.

Typical examples of polyether are polyethylene glycol and polypropylene glycol.

The proportion of unsaturated cycloacetal and polyvalent hydroxyl compound to be used varies depending on the type of polyvalent hydroxyl compound, required molecular weight, viscosity, and physical properties, but 1 part of polyvalent hydroxyl compound is used per 100 parts of unsaturated cycloacetal.
Available in a range of 0 to 1000 copies.

Furthermore, as an example of isocyanate, a type having two or more incyanate groups in one molecule is suitable.

Examples of these are tolylene diisocyanate, diphenylmethane diinocyanate, hexamethylene diisocyanate, inphorone diisocyanate, xylylene diisocyanate and adducts of these incyanates with polyhydric alcohols.

Examples of the alcohol having an unsaturated group for reacting with incyanate to introduce a radically curing unsaturated bond include those having an acryloyl group or a methacryloyl group.

Examples include 2-hydroxyethyl acrylate, 2-
Examples include hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, trimethylolpropane diacrylate, and pentaerythritol triacrylate.

It is necessary that the polymer has two or more unsaturated bonds in one molecule at the end of the molecule or in the side chain.

In some cases, one molecule per molecule may be included, but if all of them are of such kind, it does not meet the purpose of the present invention.

One purpose of the resin according to the present invention is to use it for photocuring in combination with a photocuring agent, but it can also be used for FRP, paints, and adhesives using a general radical curing catalyst. It is.

In addition, it goes without saying that inorganic or organic fillers, reinforcing materials, dyes and pigments, mold release agents, various polymers or prepolymers, etc. can be used when utilizing these materials.

Next, examples will be shown below to help understand the present invention.

Example 1 1 equipped with a stirrer, a reflux condenser, and a thermometer was placed in a three-meter flask, and diarylidene pentaerythritol 2121
, ethylene glycol 136P.

Prepare 1.2y of para-toluenesulfonic acid, 90-95
After reacting at ℃ for 3 hours, a reaction rate of 98%, a viscosity of about 200 poise, and a light reddish-brown resin with ethylene glycol added to the unsaturated bonds at both ends of diarylidene pentaerythritol (
a) is obtained.

Add 1 g of triethylamine to stop the reaction, then heat at 60°C for 5 minutes.
Remove volatiles by reducing the pressure to mmHg K for 30 minutes.

The hydroxyl value is approximately 330 (theoretical value 390).

Separately, put xylylene diincyanate 188'i? was charged, and 100f of 2-hydroxyethyl acrylate was added dropwise while raising the temperature to 60°C.

After completion of the dropwise addition, stirring is continued for 2 hours at 60 to 70°C to synthesize unsaturated isocyanate (b).

It is a pale yellow, low viscosity liquid.

tree J] ma > 350 y, unsaturated incyaner)
(b) 570t, dibutyltin dilaurate 2z, hydroquinone 0.4f1) Rimethylolpropane triacrylate 280? Place 2 into a Mitsuro flask equipped with a stirrer, a reflux condenser, and a thermometer, and heat at 80 to 88°C.
After time reaction, almost all free hydroxyl groups disappear according to infrared analysis.

After the reaction is complete, an adduct of diarylidene pentaerythritol and 2-hydroxyethyl acrylate (
c) 300f was added to dissolve penzoin isoglobyl ether 301 to produce photocurable resin CI).

When photocurable resin [D] was applied to a steel plate for painting to a thickness of 0.2 mm and irradiated with 15 CIIL under a high-pressure mercury lamp of 80 W/cfrL, it gelled in 3 seconds and cured in 8 to 10 seconds, resulting in extremely fast curing. .

Pencil hardness of cured coating film: 3H, rough edges) 25/25
Both adhesion and hardness were good.

Example 2 Into a four-eye flask equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, neopentyl glycol 1 was added.
35P, ethylene glycol 43r1 para-toluenesulfonic acid 2f, hydroquinone 0.22, 95~
Diarylidenepentaerythritol) 311' is added little by little while heating to 100°C.

After the addition, the reaction was carried out at 90° C. for 6 hours, and analysis of hydroxyl groups and unsaturated bonds showed that the reaction had progressed to 98%.

An additional polyhydric alcohol (d) having a viscosity of about 4,500 poise, a hydroxyl value of 160, and a reddish brown color was obtained.

Furthermore, diethylamine 11 and dibutyltin dilaurate 21 were added to (d), the temperature was lowered to 80°C, and a solution of an adduct of tolylene diin cyanate 280P and 2-hydroxyethyl methacrylate 171P dissolved in styrene 150y' was added dropwise.

After continuing the reaction at the same temperature for 3 hours after the dropwise addition, styrene 3
50'? is added to obtain a styrene solution of unsaturated polyurethane having a light brown color and a viscosity of about 11 poise.

This is called resin. To resin (e) 100P, 1.5 parts of methyl ethyl ketone peroxide and 0.8 parts of cobalt nanthenate (6% Co) were added, and laminated at room temperature using a #450 glass mantle to form a laminate with a glass content of 31%. Manufactured.

During curing, the surface exposed to air was dry to the touch without being affected by the curing inhibiting effect of air.

Acid value 31.9 produced from 10.5 moles of neopentyl glycol, 5 moles of isophthalic acid, and 5 moles of fumaric acid.
A laminate using an unsaturated polyester resin (1) obtained by dissolving unsaturated polyester 100OP in 500S' styrene and curing under the same conditions remained sticky in the air.

Table 1 shows the physical properties of the laminate using the above resin.

Example 3 In a four-eye flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser, a hydroxyl value of 140 and a pale yellow, white-grain-like substance prepared from 12 moles of ethylene glycol, 6 moles of fumaric acid, and 4 moles of isophthalic acid were added. 8001 g of hydroxyl unsaturated polyester, 141 g of diarylidene pentaerythritol, and 3 t of paratoluenesulfonic acid were prepared.
After reacting at 00 to 105°C for 5 hours, the hydroxyl value reached 46, indicating that the reaction was almost complete.

If the contents become viscous at the end of the reaction, styrene 1601,
Add 0.5P of hydroquinone.

The following is a 1:1 adduct of 1 mole of xylylene diinicyanate and 1 mole of 2-hydroxypropyl methacrylate 2
05P is added dropwise at a temperature of 80-85°C.

Benzyldimethylamine 3i and dibutyltin dilaurate 3P were added prior to the dropwise addition, and when the reaction was continued at the same temperature for 3 hours after the dropwise addition, it was observed as a result of infrared analysis that the free hydroxyl value almost disappeared.

Styrene 350? is added, and unsaturated urethane Jugetsu-chouben is obtained in a light reddish-brown liquid form.

Unsaturated urethane resin (2) 100f, cumene hydroperoxide 21, cobalt nanthenate 1? and apply it to a thickness of 0.2 mm on a 10 mm thick plywood that has been sealed.

It gels in 23 minutes and is dry to the touch after 1 hour.

The pencil hardness of the coating film after 24 hours was H, meaning it could be polished.

When unsaturated urethane resin (5) with the same composition except for diarylidene pentaerythritol was used, the coating remained somewhat sticky even after 24 hours, and could not be polished.

Example 4 Add polyethylene glycol 40 to a four-eye flask equipped with a stirrer, thermometer, dropping funnel, and reflux condenser.
0 to 4001, diarylidene pentaerythrit 106
1. Prepare para-toluenesulfonic acid 1.5Z, 85~
When reacting at 90°C for 3 hours, 95 (%) of unsaturated bonds disappear.

Furthermore, 1 M' of dimethylaminoethanol and 2 P of dibutyltin dilaurate were added, and 1,501 l of a 1:1 adduct of hexamethylene diisocyanate and 2-hydroxypropyl acrylate were added, and the reaction was continued at 80 to 85°C for 3 hours to liberate As a result of infrared analysis, it was observed that the hydroxyl groups in the sample had almost disappeared.

Add to this 150 trimethylolpropane triacrylate
'f! ', benzophenone 10'f? , and 5 g of benzoin isopropyl ether were added to obtain a light-yellow-brown photocurable resin (i) with a viscosity of 63 poise.

Apply this to a thickness of 0.2 mrn on a glass plate, and
It was irradiated with 10 CrfL under a mercury lamp of /cm.

It gels after 2-3 seconds, hardens in 8 seconds, and the surface pencil hardness is F.
Met.

A photocurable resin stamp with the same formulation except for diarylidene pentaerythritol gelled in air, but the surface was not sufficiently cured, making it difficult to measure hardness.

Claims (1)

[Claims] 11A:l Unsaturated cycloacetal obtained by condensation of α-β unsaturated aldehyde and polyhydric alcohol ((
), (1) polyhydric alcohol, (11) polyester,
(m) A prepolymer or polymer having two or more hydroxyl groups obtained by reacting both with at least one compound selected from polyethers (2) having two or more hydroxyl groups in one molecule. ] Polyvalent incyanato (1
) and an unsaturated urethane compound obtained by reacting with a hydroxy unsaturated compound (2) that shares a radically curable unsaturated bond and a hydroxyl group in the same molecule. Production method.