JPH01229062A - Curable resin composition - Google Patents

Abstract

PURPOSE:To obtain a curable resin composition, improved in solvent resistance by three dimensional crosslinking while maintaining toughness and suitable as coatings, etc., by reacting a polyurethane resin with a specific monomer mixture and blending the resultant graft polymer with a crosslinking agent. CONSTITUTION:A curable resin composition obtained by blending (A) a graft polymer prepared by reacting a radically polymerizable monomer mixture containing a hydroxyl group-containing alpha,beta-ethylenically unsaturated monomer [e.g., hydroxyethyl (meth)acrylate] and a carboxyl group-containing alpha,beta- ethylenically unsaturated monomer (e.g., acrylic acid or methacrylic acid) with a polyurethane resin with (B) a crosslinking agent (e.g., polyisocyanate compound or melamine resin) in an amount of 2-30 pts.wt. based on 100 pts.wt. solid of the component (A).

Description

DETAILED DESCRIPTION OF THE INVENTION (Objective of the Invention) (Industrial Application Field) The present invention relates to a graft-type curable polyurethane resin composition useful in the fields of paints, printing inks, adhesives, and the like.

(Prior Art) Thermoplastic polyurethane resins have traditionally been used in various protective coatings, printing inks, etc., taking advantage of their excellent properties such as toughness and abrasion resistance.

However, as is well known, these polyurethane resin paints do not have a three-dimensional crosslinking agent structure and utilize lacquer-type drying, so they are easily attacked by early solvents, and their uses are severely restricted.

(Problems to be Solved by the Invention) As mentioned above, conventional polyurethane resins lack consideration for three-dimensional crosslinking, and there are no reactive residues such as hydroxyl groups in the polyurethane molecule that serve as crosslinking points. Either there is none, or even if it exists, the amount is so small that its content is unknown. Therefore, no attempt has been made to actively three-dimensionally crosslink polyurethane resins to solve the above-mentioned problems.

An object of the present invention is to make polyurethane resin capable of three-dimensional crosslinking and to expand the field of use of polyurethane resin.

(Structure of the Invention) (Means for Solving the Problems) To summarize the present invention, the present invention provides a hydroxyl group-containing α,β-ethylenically unsaturated septamer and a carboxyl group-containing α,β-ethylenically unsaturated septamer. Regarding a curable resin composition consisting of a graft polymer (A), which is obtained by reacting a radically polymerizable polymer mixture containing a saturated monomer with a polyurethane resin, and a crosslinking agent (B), the toughness of the polyurethane resin is particularly maintained. The present invention also relates to a novel graft-type curable polyurethane resin composition that can improve solvent resistance through three-dimensional crosslinking.

Hereinafter, the configuration of the present invention will be explained in detail.

In the production of the graft polymer (A) of the present invention,
An α,β-ethylenically unsaturated monomer containing hydroxyl group-containing α,β-ethylenically unsaturated monomerfoxyl is essential as the heptadmer to be grafted onto the polyurethane resin.

The hydroxyl group-containing α,β-ethylenically unsaturated monomers include hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate, or caprolactone-modified products of these hydroxyalkyl (meth)acrylates. (Plaxel FH series: manufactured by Daicel Chemical Industries, Ltd.), (meth)acrylic acid ester of polyether diol, ie, hydroxypolyalkylene ether glycol 7-(meth)acrylate, and the like.

Examples of the carboxyl group-containing α,β-ethylenically unsaturated septamer include acrylic acid, methacrylic acid, maleic acid, itaconic acid, and crotonic acid.

The hydroxyl group-containing α,β-ethylenically unsaturated hexamer increases the reactivity with the crosslinking agent (B) described below, and improves the crosslinked structure of the entire coating film prepared from the curable resin composition of the present invention. In order to make it uniform, it needs to be contained in the total monomer mixture in an amount of 5 mol % or more, preferably 10 mol % or more. However, in order to prevent clouding during grafting,
A content of mol % or less is preferable.

Similarly, the carboxyl group-containing α,β-ethylenically unsaturated monomer improves compatibility with the crosslinking agent (B),
From the viewpoint of forming a homogeneous rear film, it is necessary to contain it in an amount of 1 mol % or more, preferably 2 mol % or more in all monomers. However, if too much is used, the water resistance will deteriorate, so the limit is about 20 mol%.

In the present invention, in addition to the above-mentioned essential monomers, copolymerizable unsaturated monomers such as methyl (meth)acrylate, ethyl Alkyl (meth)acrylates such as (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate; Alkylamino (meth)acrylates such as dimethylaminoethyl (meth)acrylate; oxyalkyl (meth)acrylate phosphate , dicyclopentenyl (meth)acrylate, N-vinylpyrrolidone, acrylonitrile, styrene, acrylamides, vinyltoluene, vinyl acetate, etc., may be used in combination as needed.

As the polyurethane resin which is the filler polymer of the graft polymer (A) used in the present invention, polyurethane resins and/or polyurethane urea resins (hereinafter collectively referred to as (called polyurethane resin) can be used. The polyurethane resin has a molecular weight of 5,000
~50.000. Preferably a,ooo~30.000
In addition, in order to smoothly carry out the graft copolymerization reaction, 0.2 to 3, preferably 0.5
Those having ~2 α,β-ethylenically unsaturated bonds are preferred.

As a means for introducing α,β-ethylenically unsaturated bonds into the polyurethane resin, an appropriate amount of maleic acid, itaconic acid, etc. may be co-condensed with the polyester diol used in producing the polyurethane resin.

Examples of polyols used in the production of polyurethane resins include polyester diols having α,β-ethylenically unsaturated bonds, as well as α.

Bifunctional alcohol raw materials such as polyester diol, polycaprolactone diol, polyether diol, carbonate diol, ethylene glycol, propylene glycol, butane diol, hexane diol, cyclohexane dimetatool, neopentyl glycol, etc. that do not contain β-ethylenically unsaturated bonds may be used in combination. Furthermore, if a higher molecular weight polyurethane resin is desired, a small amount of tri- or higher functional alcohols such as trimethylolpropane, trimethylolethane, pentaerythritol, etc. can be used together, but the amount used depends on the gelation caused by three-dimensionalization. Needless to say, it is necessary to take these settings into account.

In addition, as isocyanate raw materials used in the production of polyurethane resin, there are known diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, and these may be used alone or in combination of two or more. be able to.

The polyurethaneurea resin used in the present invention is prepared by producing a prepolymer containing terminal isocyanate groups by a known method using one or more of the above polyol compounds and one or more polyisocyanates. It can be obtained by performing a chain elongation reaction using a diamino compound having two primary and/or secondary amino groups in the molecule using a known and publicly used method.

Examples of the diamino include ethylene diamino,
Examples include propylene diamino, hexamethylene diamino, piperazine, isophorone diamino, /1,4'-diaminodicyclohexylmethane, and the like.

In the production of the polyurethane resin or polyurethaneurea resin described above, in any case, monoalcohols such as methanol, ethanol, propatool, monoaminos such as diethylamino, dipropylamino, dibutylamino, monoethanolamino, jetanol amino, mono Alkanol aminos such as propaturamino and dibrobanol amino can be used as chain extension terminators.

When producing the graft polymer (8) using the above-mentioned graft monomer and polyurethane resin as the backbone polymer, the catalyst for the graft copolymerization reaction is azobisisobutyronitrile, benzoyl peroxide,
Known and commonly used radical polymerization catalysts such as di-tert-butyl peroxide and cumene hydroperoxide are used. Furthermore, it goes without saying that during the graft copolymerization reaction, the viscosity of the reaction system can be adjusted by using one or more types of organic solvents that are publicly known and in use.

In the present invention, the ratio of the 7-mer mixture reacted with the polyurethane resin is 4 parts or more, preferably 5 parts or more based on 100 parts of the polyurethane resin in terms of solid content, from the viewpoint of improving solvent resistance, which is the gist of the present invention. However, if the amount is too large, the toughness and abrasion resistance specific to the polyurethane resin will be greatly influenced by the copolymerization monomer composition, so it is necessary to appropriately control the ratio. For example, although solvent resistance is maintained and improved, other coating film properties are impaired, so it is preferable to react the seven-mer mixture at a solid content ratio of up to the same ratio.

In the present invention, as the crosslinking agent (B) used together with the graft polymer (A), there are polyisocyanate resins, amino resins, etc. that are well known and commonly used in the paint industry, printing ink industry, etc. For example, as the polyisocyanate resin, , Parnock D-750, Parnock DN-9
50, Parnock D-800, Parnock D-802,
Examples include Parnock DN-980 and Parnock DN-981 (manufactured by Dainippon Ink and Chemicals Co., Ltd.).

Also, as amino resins, urea, melamine, benzoguanamine, etc. are methylolated and methoxylated.

Known and commonly used resins treated with butoxylation and the like can also be used. For example, there are Beckamin, Super Beckamin series (manufactured by Dainippon Ink and Chemicals Co., Ltd.), Cymel series (manufactured by Mitsui Toatsu Chemical Co., Ltd.), and Nikaratsuku series (manufactured by Nippon Carbide Industries Co., Ltd.). .

The blending ratio of the graft polymer (A) and crosslinking agent CB) depends on the type and combination of each, but if the blending amount of the crosslinking agent is too small, sufficient three-dimensional network bonding will not be obtained, resulting in poor solvent resistance. does not improve. Furthermore, if there is too much crosslinking agent, the self-condensation of the crosslinking agents will proceed too much, resulting in an unnecessary increase in crosslinking density. The blending ratio is determined as appropriate, taking into consideration the following: the structural rigidity will become too high, resulting in a brittle coating film, and in severe cases, the crosslinking agent may remain unreacted, deteriorating solvent resistance. All you have to do is decide. A rough guideline for carrying out the present invention is to add the crosslinking agent (B) to 100 parts of the solid content of the graft polymer (A).
The amount of solid content is selected within the range of 2 to 30 parts.

In the curable resin composition of the present invention, in addition to the graft polymer (A) and the crosslinking agent (B), organic solvents, leveling agents, thixotropy imparting agents, and silane coupling agents that are commonly used in the paint field, printing ink field, etc. It goes without saying that , titanium coupling agents, dyes, pigments, matting agents, curing catalysts, etc. can be used as appropriate.

The curable resin composition of the present invention prepared as described above is useful for various uses such as paints, inks, and adhesives.

When a paint etc. is prepared from the curable resin composition of the present invention,
These are spray painting, curtain flow painting, roll coater painting, and doctor knife painting.

It can be coated by known and commonly used methods such as dip coating, spin coater coating, brush coating, and flow coating.

The curing conditions for the painted film are O to 300'C, preferably 10 to 200'C.

The composition of the present invention is useful for protecting plastics that have poor solvent resistance as materials, but is not limited to these materials, such as metals, glass, and wood agents.

Of course, various base materials such as paper and ceramics can also be coated.

Furthermore, even for pre-processed materials, it can be used in any combination with a film forming layer formed by a known and commonly used method such as a coating agent other than the present invention, ink, vapor deposition, ion blasting, sputtering, etc. You can also.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Synthesis Examples and Examples, but the present invention is not limited to these Examples. All parts are in parts by weight unless otherwise noted.

Synthesis example 1. (Synthesis of polyester diol for polyurethane resin) Polyester diol was synthesized by a conventional method using the composition shown in Table 1. The properties of the obtained polyester diol are also shown in the same table.

(Hereinafter in the margin) Table 1 (Synthesis examples of polyester diol) (Hereinafter in the margin) Synthesis example 2. (Synthesis of polyurethane resin) (2-1: Polyurethane resin) A predetermined amount of the polyester diol prepared in Synthesis Example 1 and an organic solvent were charged into a reaction tank equipped with a reflux condenser and a stirrer, and the temperature was raised to 60 to 70"C. Then, a predetermined amount of diisocyanate was gradually added to carry out the urethanization reaction.A reaction catalyst was added as necessary before or during the reaction, and diluted with an organic solvent to cope with the increase in viscosity as the reaction proceeded. did.

The progress of the reaction was monitored by observing the Gardner viscosity at 25°C in a predetermined nonvolatile content, and when the target viscosity was reached, the addition of diisocyanate was stopped, and then the temperature was kept at 70°C for about 3 hours.
The reaction was completed by holding at Table 2 shows the composition and properties of the polyurethane resin prepared.

(Left below) (2-2: Polyurethane urea resin) Add a predetermined amount of the diisocyanate raw material and organic solvent to the above 2-
The mixture was placed in a reaction tank similar to 1, and the temperature was raised to 60°C. Next, a predetermined amount of polyester diol raw material was charged in its entirety, taking care not to generate heat, and maintained at 70°C to obtain a prepolymer containing terminal incyanate groups.

The obtained prepolymer was diluted with a solvent and heated at 30-40°C.
After cooling to , diamino in an amount equivalent to the remaining isocyanate group was gradually added to carry out a urea reaction.

The reaction was followed by Gardner viscosity at 25°C, and the addition of diamino was discontinued when the target was reached.

Next, the same mole of monoamino or monoalcohol as the number of equivalents of the remaining diamino, such as dialkylaminos such as diethylamino and dibutylamino, monoalkanolaminos such as monoethanolamino, monoalcohols such as methanol, ethanol, butanol, etc. Add, 70'
C for 3 hours to block the remaining isocyanate groups and complete the reaction.

Table 3 shows the composition and properties of the prepared polyurethaneurea resin.

Synthesis example 3. (Synthesis of graft polymer) Synthesis Example 2-
The polyurethane resins given in 1 and 2-2 were placed in the same reaction tank as in 2-1, and the temperature was raised to 100'C. If the boiling point of the solvent was 100°C or lower, the temperature was raised to its reflux temperature.

Next, a pre-mix of a heptamine mixture and a radical polymerization catalyst in a predetermined amount is charged over a period of 30 minutes to 1 hour, and while adding an appropriate amount of a radical polymerization catalyst, the reaction is continued until the monomer reaction rate reaches 95% or more. Continued.

The progress of the reaction was followed by measurements of viscosity and non-volatile content.

Table 4 shows the composition and properties of the prepared graft polymer.

(The following is a blank space) By the way, from Table 4, as polyurethane resin components, u-5 and u-
In Sample No. 10, the graft copolymerization reaction did not occur, and the reaction system became cloudy (experiment numbers G-51 and G-101).

Examples/Comparative Examples Next to the various polymers prepared in Synthesis Example 2 and Synthesis Example 3, paints were formulated to confirm the effects of the present invention, and the gel fractions of each were measured after coating, drying, and curing. .

The paint formulations, including the comparative examples, were made according to the above Tables 5-1 and 5-2, and the paints were applied onto release paper using an applicator, and about 501 m of dry film was removed. This dry film was immersed in azetone at room temperature for 24 hours, and its gel fraction was measured. The results are shown in Tables 5-1 and 5-2 together with formulation examples.

Examples No. 1 to B all showed high gel fractions, indicating that they were in a good three-dimensional crosslinked state.

On the other hand, in the comparative example, when a polyurethane resin without grafting reaction was used (comparative example No. 11
-14) have extremely low gel fractions and lack practicality. In addition, even if the graft reaction is carried out, a monomer mixture containing a hydroxyl group is not used in combination (No.
, 15.16> does not improve the gel fraction and does not use a carboxyl group-containing monomer (No, 17.1
No. 8> has poor compatibility with the crosslinking agent, leaves applicator marks, becomes cloudy, and lacks practicality.

Roughly, the ratio of polyurethane resin and monomer mixture is 1
When using a 00:3 graft polymer <No, 1
9.20) shows an improvement in gel fraction, but is insufficient for practical use.

(Left below) (Effects of the invention) By using the curable resin composition of the present invention, it is possible to obtain solvent resistance that cannot be obtained with conventional urethane elastomers, and it is also possible to obtain solvent resistance that cannot be obtained with conventional urethane elastomers. It provides coating film properties with excellent toughness and elasticity that cannot be obtained with paints, acrylic paints, etc. Therefore, by mutually complementing these excellent properties, it is possible to protect various base materials and work with solvent-based adhesives, etc.
It is also possible to greatly improve processing characteristics.

That is, the curable resin composition of the present invention is extremely useful in the field of painting and processing, etc., where it is desired to take advantage of the physical properties of urethane resins in coatings, but which cannot be used due to poor solvent resistance.

Claims (3)

[Claims] (1) Graft polymer (A) obtained by reacting a radically polymerizable monomer mixture containing a hydroxyl group-containing α,β-ethylenically unsaturated monomer and a carboxyl group-containing α,β-ethylenically unsaturated monomer with a polyurethane resin
, and a crosslinking agent (B). (2) The curable resin composition according to claim 1, wherein the crosslinking agent (B) is a polyisocyanate compound. (3) The curable resin composition according to claim 1, wherein the crosslinking agent (B) is an amino resin such as a melamine resin or a benzoguanamine resin.