JP3067410B2 - Method for producing polyurethane polyurea resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polyurethane polyurea resin, and more particularly to a method for producing a resin for printing ink. More specifically, it is particularly useful as a coating for various plastic films, plastic sheets, or synthetic resin molded products, and is particularly excellent in adhesion to substrates such as polypropylene, polyester, and nylon. The present invention relates to a method for producing a resin for printing ink having excellent retort resistance.

[0002]

2. Description of the Related Art As printing ink compositions used for plastics, especially for plastic films such as polypropylene, polyester and nylon, there are two-part printing ink compositions containing a linear polyurethane resin soluble in an organic solvent as a main binder. A two-pack type using a mixture of a linear polyurethane resin soluble in an organic solvent and a polyisocyanate compound as a main binder is used, and is used depending on the type and use of a printing medium. Of these, the one-pack type printing ink composition has good adhesion to plastics and suitability for lamination to plastic films, but is adequate for applications requiring high resistance such as boil sterilization and retort sterilization. There was a disadvantage that it could not be done.

[0003] In addition, although the two-pack type can sufficiently cope with applications requiring high resistance, a polyisocyanate compound is added to a component containing a linear polyurethane resin and mixed immediately before use from the viewpoint of storage stability. However, there are drawbacks in that the operation is complicated, that the remaining meat lacks stability, and that it is difficult to reuse the remaining meat. In order to improve these drawbacks, various one-part inks having boiling and retort suitability have been proposed in recent years. However, storage stability of the ink, print suitability, anti-blocking property, general-purpose use for various films have been proposed. Two-component type that combines a one-component type ink and a polyisocyanate-based curing agent depending on the application, because it does not have the performance required for industrial printing inks, such as properties such as properties, boiling, retort suitability, etc. At present, ink is used properly.

[0004]

The present inventors have made intensive studies to solve the above problems, and as a result, have found that printing using a polyurethane resin containing a specific amount of an alkoxysilyl group in a molecule as a main binder is performed. Ink shows excellent adhesion to plastic films such as polyester, nylon, and polypropylene, has boil and retort suitability, and has excellent storage stability.
The present invention has been completed.

[0005]

That is, a first aspect of the present invention provides a method for converting a hydroxyl group in a polyol having a molecular weight of 500 to 3,000 and an isocyanate group in a diisocyanate compound under the condition that an isocyanate group is excessive relative to the hydroxyl group. The reaction is carried out to obtain a urethane prepolymer having an isocyanate group at the terminal. Then, the urethane prepolymer and the amino group in the alkoxysilane compound having two amino groups are represented by the following general formula (1) per 1 g of solid content. A method for producing a polyurethane polyurea resin, characterized in that it is reacted so as to contain 1.0 × 10 ⁻⁵ to 5.0 × 10 ⁻⁴ mol of the alkoxysilyl group to be produced,

[0006]

Embedded image (In the formula, R ₁ and R ₂ each independently represent a methyl group or an ethyl group, and n represents 2 or 3.)

A second invention is the production method according to the first invention, wherein the polyurethane polyurea resin is a resin for printing ink.

The polyurethane polyurea resin produced by the production method of the present invention is prepared by reacting a high molecular weight polyol having a specific molecular weight with a diisocyanate compound under conditions capable of leaving an isocyanate group at a terminal to obtain a polyurethane prepolymer. A chain extender obtained by reacting an alkoxysilane compound having two amino groups with an alkoxysilyl group content of 1.0 g per 1 g of solid content of polyurethane polyurea resin.
It is important to make the reaction to be from ^10-5 to ^5.010-4 mol. When the content is less than 1.0 × 10 ^-5 mol, it is difficult to obtain physical properties such as boil resistance and retort resistance of the printed matter when used in a printing ink, and when the content is more than 5.0 × 10 ^-4 mol, polyurethane is used. The viscosity stability over time of the polyurea resin solution is reduced, and the printing ink using the polyurethane polyurea resin tends to increase in viscosity and gel.

The polymer polyol used in the present invention has a solubility of the obtained polyurethane polyurea resin,
The molecular weight is 500 ~ from the viewpoint of drying property, blocking resistance, etc.
It is important to be in the range of 3000, and even 700-25
It is preferably in the range of 00. If the molecular weight is less than 500, the printability tends to be inferior due to the decrease in solubility,
On the other hand, when it exceeds 3,000, drying properties and blocking resistance tend to decrease.

The polymer polyol used in the present invention includes, for example, ethylene oxide, propylene oxide,
Polyether polyols such as polymers or copolymers such as tetrahydrofuran; ethylene glycol, 1,2-
Propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, hexanediol, octanediol, 1,4-butynediol, diethylene glycol,
Saturated and unsaturated low molecular weight glycols such as triethylene glycol and dipropylene glycol;
Alkyl glycidyl ethers such as butyl glycidyl ether and 2-ethylhexyl glycidyl ether; glycidyl esters of monocarboxylic acid such as glycidyl versatate; and adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, and amber Polyester polyols obtained by dehydrating and condensing dibasic acids such as acids, oxalic acid, malonic acid, glutaric acid, pimelic acid, speric acid, azelaic acid, sebacic acid, and dimer acid; Polyester polyols obtained by ring-opening polymerization;
In addition, various known high molecular polyols generally used in the production of polyurethane, such as polycarbonate polyols, polybutadiene glycols, and glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A, may be mentioned. These polymer polyols may be used alone or in combination of two or more.

[0011] Among these high molecular polyols,
When a polymer polyol obtained from a glycol and a dibasic acid is used, up to 5 mol% of the glycol can be replaced with the following various polyols. That is, for example, glycerin, trimethylolpropane,
Trimethylolethane, 1,2,6-hexanetriol, 1,
It may be replaced by a polyol such as 2,4-butanetriol, sorbitol, pentaerythritol and the like.

As the diisocyanate compound used in the present invention, various known aromatic, aliphatic or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane
-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate Isocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane
Representative examples include -4,4'-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexanediisocyanate, m-tetramethylxylylene diisocyanate, and dimer isocyanate in which the carboxyl group of dimer acid is converted to an isocyanate group. No.

The polyurethane prepolymer is preferably prepared by reacting a high molecular polyol and a diisocyanate compound at a ratio at which isocyanate groups become excessive, for example, an equivalent ratio of hydroxyl group / isocyanate group is within a range of 1 / 1.2 to 1/3. Such a polyurethane prepolymer has isocyanate groups at both ends, and preferably has a free isocyanate value of 0.5 to 10%.

Next, the polyurethane prepolymer is reacted with an alkoxysilane compound having two amino groups as a chain extender in a suitable solvent to obtain a polyurethane polyurea resin having a specific amount of alkoxysilyl group.

The alkoxysilane compound having two amino groups used as a chain extender in the present invention includes, for example, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ −
Aminopropylmethyldimethoxysilane and the like.

As the chain extender, various known diamines can be used in combination with the alkoxysilane compound having two amino groups, if necessary. For example, ethylenediamine, propylenediamine, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, dicyclohexylmethane-4,4′-diamine and the like can be mentioned. In addition, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, etc. Representative examples thereof include diamines having a hydroxyl group and dimer diamine obtained by converting a carboxyl group of a dimer acid into an amino group.

In order to obtain the desired polyurethane polyurea resin, a monoamine component or a monoalcohol component can be further used as a reaction terminator. Examples of such a monoamine component include an alkoxysilyl group-containing monoamine generally known as a silane coupling agent, such as γ-aminopropyltriethoxysilane and N-phenyl-γ-aminopropyltrimethoxysilane,
dialkylamines such as n-butylamine;
Examples of the monoalcohol component include alcohols such as ethanol and isopropyl alcohol.

The reaction of the polyurethane prepolymer with the above-mentioned alkoxysilane compound having two amino groups and other optional diamine components is carried out when the free isocyanate groups at both ends of the prepolymer are 1 equivalent. , Amino groups and the like are preferably in the range of 0.5 to 1.30. When the total equivalent weight of amino groups and the like is less than 0.5, when the obtained polyurethane polyurea resin is used for a printing ink, the drying property, the blocking resistance, and the film strength are not sufficient. Amino groups and the like in the terminator remain unreacted, and odor tends to remain on printed matter.

The number average molecular weight of the polyurethane polyurea resin containing an alkoxysilyl group in the molecule is from 5,000 to
A range of 150,000 is preferred. When the number average molecular weight is less than 5,000, the printing ink using this as a binder is
It has poor drying properties and blocking resistance, and it is difficult to obtain physical properties such as film strength and boiling and retort resistance. Also, 150,00
If it exceeds 0, the viscosity of the polyurethane resin solution increases, which is not preferable in terms of storage stability and printability of the ink. Further, the polyurethane polyurea resin containing an alkoxysilyl group in the molecule may have various functional groups such as a hydroxyl group, an amino group and a carboxyl group in addition to the alkoxysilyl group.

Examples of the solvent used in the above-mentioned production method include aromatic solvents such as benzene, toluene and xylene, which are well known as solvents for printing inks.
Methanol, ethanol, isopropanol, alcohol solvents such as n-butanol, acetone, methyl ethyl ketone, ketone solvents such as methyl isobutyl ketone, ethyl acetate, ester solvents such as butyl acetate, and the like,
These are used alone or in a mixture of two or more.

In the case of producing a printing ink, various pigments and the above-mentioned solvent are added to the above-mentioned alkoxysilyl group-containing polyurethane polyurea resin, if necessary, additives such as an antiblocking agent and a plasticizer, ink fluidity and the like. Surfactant for improving dispersibility, or having compatibility with the polyurethane polyurea resin, and thickening over time, nitrified cotton, chlorinated polyethylene, chlorinated polypropylene, chlorine as long as gelation does not occur Ethylene chloride /
Chlorinated polyolefins such as propylene, chlorsulfonated polyolefins, ethylene / vinyl acetate copolymers, or chlorinated or chlorsulfonated products thereof, maleic acid resins, vinyl chloride / vinyl acetate copolymers, and resins such as polyurethanes, The kneading is carried out using an ordinary printing ink manufacturing apparatus such as a ball mill, an attritor, and a sand mill.

[0022]

[Example 1]

In a four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, 100 parts of polycaprolactone diol having a molecular weight of 2,000 and isophorone diisocyanate
22.2 parts were charged and reacted at 85 ° C. for 6 hours under a nitrogen stream. Then, 2.1 parts of N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, 6.1 parts of isophoronediamine, 1.3 parts of di-n-butylamine, and toluene 123
Parts, 123 parts of methyl ethyl ketone and 62 parts of isopropyl alcohol were added and reacted at 50 ° C. for 3 hours with stirring.
Solid content 30%, viscosity at 25 ° C 900cps, molecular weight 60,000
To obtain a polyurethane polyurea resin solution (A) containing an alkoxysilyl group.

[0023] The obtained polyurethane resin solution (A)
After placing in a 00 ml glass sample bottle and left at 40 ° C. for 1 week, the storage stability was evaluated. Table 1 shows the results. …: No increase in viscosity or gelation is observed as compared to immediately after production. Δ: No gelation, but an increase in viscosity is observed as compared to immediately after production. ×: Gelling as compared to immediately after production.

Next, 40 parts of a polyurethane resin solution (A),
A mixture of 30 parts of titanium oxide, 15 parts of toluene and 15 parts of methyl ethyl ketone was kneaded to prepare a white printing ink.
Further, the viscosity of the obtained printing ink was adjusted with a mixed solvent of toluene, methyl ethyl ketone and isopropyl alcohol (weight ratio 60:30:10), and a corona-treated polyester film (PET) was obtained using a gravure proofing machine equipped with a 35 μm deep gravure plate. ) And corona-treated nylon film (NY) and dried at 40 ° C. to 50 ° C. to obtain a printed material. The obtained printed matter was evaluated for adhesion, extrusion lamination strength, dry lamination strength, boil aptitude, and retort aptitude. Table 1 shows the results. In addition,
The evaluation was performed by the following test methods.

1) Adhesion After the printed matter was allowed to stand for one day, a cellophane tape was stuck on the printed surface, and the appearance of the printed film when the tape was rapidly peeled was visually judged. The criteria were as follows. A: The printed film did not come off at all. …: 80% or more of the printed film remained on the film. Δ: 50% to 80% of the print film remained on the film. X: 50% or less of the printed film remained on the film. 2) Extrusion (EL) lamination strength Using an isocyanate-based anchor coating agent on the printed matter, laminating molten polyethylene by an extrusion laminator, aging at 40 ° C for 2 days, and 3 days after lamination, the sample was 15 mm wide. And the T-peel strength was measured.

3) Dry (DL) Laminating Strength A CPP (unstretched polypropylene) film is laminated by a dry laminating machine using a urethane-based adhesive on the printed matter, and aged at 40 ° C. for 3 days. The peel strength was measured by the method described above. 4) Suitability for boil and retort After dry lamination of the above-mentioned NY printed matter, the laminate is made into a bag, a mixture of water / salad oil is put in as a content, and after sealing, boil suitability is 100 ° C., 30 minutes, retort suitability. After heating at 120 ° C. for 30 minutes, the presence or absence of laminar floating was visually judged by appearance. The criteria were as follows. …: There is no lami floating. Δ: Delamination was found in a very small portion, or blisters were generated, albeit slightly. X: Delamination occurred on the entire surface.

Example 2 100 parts of a polyester diol having a molecular weight of 2,000 obtained from adipic acid and 1,2-propylene glycol and 100 parts of isophorone diisocyanate 2 were placed in the same reactor as in Example 1.
4.4 parts were charged and reacted at 85 ° C. for 6 hours under a nitrogen stream. Next, 11.3 parts of N-β (aminoethyl) -γ-aminopropylmethyldiethoxysilane, 2.7 parts of γ-aminopropyltriethoxysilane, 129 parts of toluene, 129 parts of methyl ethyl ketone and 65 parts of isopropyl alcohol were added, and the mixture was stirred. Reaction at 50 ° C for 3 hours, solid content 30
%, An alkoxysilyl group-containing polyurethane polyurea resin solution (B) having a viscosity of 700 cps at 25 ° C. and a molecular weight of 56,000. In the same manner as in Example 1, the storage stability of the obtained polyurethane polyurea resin solution (B) was evaluated, and an ink was further prepared and printed, followed by evaluation. Table 1 shows the results.

Example 3 In a reactor similar to that in Example 1, adipic acid and 3-methyl-
100 parts of a polyester diol having a molecular weight of 2,000 obtained from 1,5-pentanediol and 100 parts of isophorone diisocyanate were charged and reacted at 85 ° C. for 6 hours under a nitrogen stream. Then, 8.2 parts of isophoronediamine, 0.44 part of γ-aminopropyltriethoxysilane, 0.39 part of di-n-butylamine, 122 parts of toluene, 122 parts of methyl ethyl ketone and 62 parts of isopropyl alcohol were added, and the mixture was stirred.
Reaction at 50 ℃ for 3 hours, solid content 30%, viscosity at 25 ℃
A polyurethane polyurea resin solution (C) containing 650 cps and a molecular weight of 52,000 and containing an alkoxysilyl group was obtained. In the same manner as in Example 1, the storage stability of the obtained polyurethane polyurea resin solution (C) was evaluated, an ink was further prepared, and printing was performed. Table 1 shows the results.

Comparative Example 1 A similar reaction apparatus as in Example 1 was prepared by adding adipic acid and 3-methyl-
100 parts of a polyesterdiol having a molecular weight of 2,000 obtained from 1,5-pentanediol and 100 parts of isophorone diisocyanate were charged and reacted at 85 ° C. for 6 hours under a nitrogen stream. Then, 8.2 parts of isophorone diamine, 1.3 parts of di-n-butylamine, 130 parts of toluene, 1 part of methyl ethyl ketone
30 parts and 62 parts of isopropyl alcohol were added thereto and reacted at 50 ° C. for 3 hours with stirring to obtain a polyurethane polyurea resin solution (D) having a solid content of 30%, a viscosity at 25 ° C. of 550 cps and a molecular weight of 51,000. In the same manner as in Example 1, the storage stability of the obtained polyurethane polyurea resin solution (D) was evaluated, and an ink was further prepared and printing was performed. Table 1 shows the results.

[Comparative Example 2] Adipic acid and 3-methyl-
100 parts of a polyester diol having a molecular weight of 2,000 obtained from 1,5-pentanediol and 100 parts of isophorone diisocyanate were charged and reacted at 85 ° C. for 6 hours under a nitrogen stream. Then, 3.7 parts of isophoronediamine, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane
0.17 parts, di-n-butylamine 0.65 parts, toluene 113 parts,
113 parts of methyl ethyl ketone and 57 parts of isopropyl alcohol are added, and the mixture is reacted at 50 ° C. for 3 hours with stirring. A polyurethane polyurea resin solution (E) containing an alkoxysilyl group having a solid content of 30%, a viscosity at 25 ° C. of 400 cps and a molecular weight of 48,000 (E) I got In the same manner as in Example 1, the storage stability of the obtained polyurethane polyurea resin solution (E) was evaluated. Further, an ink was prepared, printed, and evaluated. Table 1 shows the results.

Comparative Example 3 The same reactor as in Example 1 was charged with 100 parts of polycaprolactone diol having a molecular weight of 2,000 and 33.3 parts of isophorone diisocyanate, and reacted at 85 ° C. for 6 hours under a nitrogen stream. Next, 20.2 parts of N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, 4.4 parts of γ-aminopropyltriethoxysilane, 147 parts of toluene, 147 parts of methyl ethyl ketone and 74 parts of isopropyl alcohol were added, and 50 parts of the mixture were stirred. C. for 3 hours, solid content 30%, 25%
A polyurethane polyurea resin solution (F) containing an alkoxysilyl group having a viscosity at 1000 ° C. of 1000 cps and a molecular weight of 60,000 was obtained. When the storage stability of the obtained polyurethane polyurea resin solution (F) was evaluated in the same manner as in Example 1, the polyurethane polyurea resin solution (F) was gelled after being left at 40 ° C. for one week, and was not suitable as a binder for printing ink.

[0032]

[Table 1]

[0033]

According to the present invention, it has excellent one-part adhesiveness to various plastic films such as polyester, nylon, polyethylene, and polypropylene used as a printing material, storage stability, and lamination processing. It is possible to provide a resin for printing ink having excellent properties such as suitability, boilability, retort suitability, and the like.

Claims (2)

(57) [Claims] 1. In a polyol having a molecular weight of 500 to 3000
Hydroxyl group and the isocyanate in the diisocyanate compound
And an isocyanate group in excess of the hydroxyl group.
Under the following conditions, and has an isocyanate group at the terminal.
To obtain a urethane prepolymer,
Repolymer and alkoxysilane having two amino groups
And a compound represented by the following general formula (1) per 1 g of solid content.
1.0 × 10 ^-5 to 5.0 × 10 ^-4 mol
Characterized in that it is reacted to have
A method for producing a urethane polyurea resin. Embedded image (In the formula, R ₁ and R ₂ each independently represent a methyl group or an ethyl group, and n represents 2 or 3.) 2. The method according to claim 1, wherein the polyurethane polyurea resin is used for printing.
2. The method according to claim 1, wherein the resin is a resin for a key.
Law