JPH05155972A - Polyurethane having rosin backbone - Google Patents

Abstract

PURPOSE:To prepare the subject polyurethane which is excellent in pigment dispersion, oil resistance, boiling resistance, and adhesion to a molded article of a plastic such as polyester, nylon, polyethylene, or polypropylene. CONSTITUTION:The objective polyurethane is prepd. by reacting a diisocyanate compd., a chain extender, and a high-molecular diol component which contains a reactional product of 1mol of a diepoxy compd. with 2mol of a rosin in such an amt. of the product that the amt. of the rosin is 3-50wt.% of the polyurethane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyurethane, and more specifically, having a rosin skeleton in the side chain in the molecule, it has excellent adhesion to various plastic moldings. And, it is intended to provide a polyurethane having high resistance.

[0002]

2. Description of the Related Art In recent years, various plastic moldings have been developed as a packaging material with the diversification of packaging objects and the sophistication of packaging technology, and those suitable for the packaging objects are appropriately selected and used. Is becoming. By the way, when a plastic molded product is used as a packaging material, it is printed or painted to decorate or protect the surface of the plastic molded product, but such a coating agent has good adhesion to these various plastic molded products. It is becoming more and more demanding to have high performance.

Polyurethane has been widely used as a binder conventionally used for such coating agents. However, for example, polyurethane may be used as a binder.
The printing ink has a good adhesion to polyester film and nylon film.
Adhesion to polyethylene or polypropylene films, which are general-purpose films, is insufficient, so when printing on polyethylene or polypropylene films, in addition to polyurethane as a binder to supplement the adhesion, rosin ester resins and ketone resins are used. , Styrene oligomers and other tackifiers are used. However, these tackifiers have a low molecular weight, and their addition has a serious drawback of deteriorating the physical properties as a coating agent such as oil resistance and boil resistance. Polyurethane generally has insufficient pigment dispersibility, has a problem in various printability or coating suitability, and has a problem that the printed matter or coating film has poor gloss. Since the addition of the above-mentioned tackifier has no effect on the improvement of the pigment dispersibility, a surfactant is used to make up for this defect, but in this case also, the physical properties such as oil resistance and boil resistance are still present. Come down.

As a tackifier or a surface treatment agent for pigments, it is possible to add rosin ester, which has been widely used in the past, to polyurethane to solve the above problems. The results were still unsatisfactory.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above problems and when used as a coating agent,
Excellent adhesion to various plastic molded products such as polyester, nylon, polyethylene and polypropylene,
It is an object of the present invention to provide a novel polyurethane having oil resistance, boil resistance, etc. and excellent in pigment dispersibility.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventor has conducted earnest studies to introduce rosins into a molecule of polyurethane rather than simply mixing them. As a result, when using a specific polyurethane in which a rosin skeleton is regularly introduced into the molecule, which is constituted by using a specific polymer polyol, it is possible to surprisingly solve the above problems. Heading out, the present invention has been completed.

The present invention provides a polyurethane obtained by reacting a high molecular diol, a diisocyanate compound and a chain extender with a reaction product of 1 molecule of a diepoxy compound and 2 molecules of rosins as a polymer diol component. Then
Further, the present invention relates to a polyurethane having a rosin skeleton, characterized in that the content of the reaction product is 3 to 50% by weight in terms of the content of rosins based on the solid content of the produced polyurethane.

The polymeric polyol characterizing the present invention is
It is a reaction product composed of one molecule of the following diepoxy compound and two molecules of rosins.

As the diepoxy compound, various known diepoxy compounds can be used without particular limitation. Specifically, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene Glycol diglycidyl ether, neopentyl glycol diglycidyl ether,
Acyclic aliphatic diglycidyl ethers such as 1,6-hexanediol diglycidyl ether; 2,2-bis (4-hydroxyphenyl) propane diglycidyl ether, bis (4-hydroxyphenyl) methane diglycidyl ether, 1, 1-bis (4-hydroxyphenyl) ethane diglycidyl ether, 2,2-bis (4-
Hydroxycyclohexyl) propane diglycidyl ether, 3,3 ', 5,5'-tetramethyl-4,4'-
Dihydroxybiphenyl diglycidyl ether, 2,
Aromatic or cycloaliphatic diglycidyl ethers such as 2′-bis (4- (β-hydroxypropoxy) phenyl) propane diglycidyl ether; 3,4-epoxycyclohexylmethyl, 3,4-epoxycyclohexanecarboxylate, vinyl Examples thereof include cycloaliphatic cyclic oxiranes such as cyclohexene dioxide.

Examples of the rosins include gum rosin, tall oil rosin, wood rosin and hydrogenated rosin. Further, it is more preferable to use a purified rosin obtained by distilling these rosins to remove unsaponifiable matters and impurities.

The reaction between the diepoxy compound and the rosins is not particularly limited and can be easily carried out by employing known reaction conditions. For example, the ring-opening addition reaction may be continued at 120 to 200 ° C. in the presence of a catalyst with 1 mol of a diepoxy compound and 2 mols of rosins until the acid value becomes 5 or less, preferably 3 or less. Examples of the catalyst include amine catalysts such as trimethylamine, triethylamine, tributylamine, benzyldimethylamine, pyridine, and 2-methylimidazole, quaternary ammonium salts such as benzyltrimethylammonium chloride, Lewis acids, borate esters, and organometallic compounds. , Organic metal salts and the like can be used. The reaction product obtained by the method has two rosin skeletons and two rosin skeletons.
It is a diol compound having a narrow molecular weight distribution having individual hydroxyl groups in the molecule (hereinafter referred to as rosin-modified polymer polyol). Further, a polymer obtained by ring-opening polymerization of ethylene oxide, propylene oxide, or ε-caprolactone using the present compound as an initiator (hereinafter, referred to as rosin-modified polymer polyol) is also the same as the rosin-modified polymer polyol. Can be used.

Next, other constituent components in the present invention will be described. In the present invention, various known polymer diols can be used in combination with the rosin-modified polymer polyol or. The combination ratio may be appropriately determined so as to be in the range of 3 to 50% by weight in terms of the content of rosins based on the solid content of the rosin-modified polymer polyol or polyurethane produced. When the content of rosin contained in the polyurethane molecule is less than 3% by weight, the adhesion to the plastic molded product and the pigment dispersibility are insufficient, and when it exceeds 50% by weight, the polyurethane skeleton becomes too hard and the flexibility is high. It becomes poor and is not preferable.

Examples of various known polymer diols that can be used in combination in the above are, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1 , 4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-
Various known saturated and unsaturated glycols such as pentanediol, 1,6-hexanediol, octanediol, 1,4-butynediol, dipropylene glycol, n-butylglycidyl ether, and 2-ethylhexylglycidyl ether. -Alkyl glycidyl ethers such as ter, monocarboxylic glycidyl esters such as versatic glycidyl ester, and adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid Acids, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, and other dibasic acids, or their corresponding acid anhydrides and dimers.
Polyester diols obtained by condensation reaction with acid, polyether diols such as polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, etc., polyester diols obtained by ring-opening polymerization of cyclic ester compounds, Other examples include polycarbonate polyols, polybutadiene glycols, glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A, and the like.

The number average molecular weight of the rosin-modified high molecular weight polyol and the number average molecular weight of the high molecular weight diol that can be used in combination with the rosin modified high molecular weight polyol are appropriately determined in consideration of the solubility, drying property and blocking resistance of the resulting polyurethane. Usually from 700 to 10000, preferably from 1000 to 6000
It is better to be within the range. If the number average molecular weight is less than 700, the printability tends to deteriorate with the decrease in solubility, while if it exceeds 10,000, the drying property and blocking resistance tend to decrease.

As the diisocyanate compound used for producing the polyurethane, 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, 2,2
4-trimethylhexamethylene diisocyanate, 2,
2,4-trimethylhexamethylene diisocyanate,
Cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,
4-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate and dimer diisocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group. Is a typical example.

As the chain extender used in the present invention, various known chain extenders can be used. 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 and other diamines having a hydroxyl group in the molecule, and the low molecular weight glycols and dimer acid carboxyl groups described in the section of the polyester diol described above as amino groups. Representative examples thereof include converted dimer-diamine and the like.

Further, a chain length terminator may be used if necessary. Examples of such chain length terminators include dialkylamines such as di-n-butylamine and ethanol.
And alcohols such as isopropyl alcohol and isopropyl alcohol.

The method for producing the polyurethane used in the present invention is not particularly limited. For example, a polymer diol component and a diisocyanate compound are reacted under an excess of isocyanate groups to form an isocyanate group at both ends of the polymer diol. A two-step process and a polymeric diol in which a prepolymer having the above (preferably an isocyanate content of 0.5 to 10%) is prepared, and then this is reacted with a chain extender and, if necessary, a chain length terminating agent in a suitable solvent. The component, diisocyanate compound, chain extender and optionally chain length terminating agent can be used in any one-step method in which they are reacted at once in a suitable solvent, but a uniform polymer solution is easily obtained. It is preferable to adopt the two-step method. During the production of these polyurethanes, various known catalysts such as tin-based catalysts such as stannous octylate may be added.

When the polyurethane used in the present invention is produced by the two-step method, the conditions for reacting the polymer diol component and the diisocyanate compound are not particularly limited, except that the isocyanate groups are excessive. Equivalent ratio of hydroxyl group / isocyanate group is 1 / 1.2 to 1/3
It is preferable that the reaction is performed within the range. The conditions for reacting the obtained prepolymer with a chain extender and optionally a chain length terminating agent are not particularly limited, but 1 equivalent of a free isocyanate group at both ends of the prepolymer is used. When the total amount of active hydrogen capable of reacting with the isocyanate group in the chain extender is 0.5 to
It is preferably in the range of 2.0 equivalents (particularly in the range of 0.5 to 1.3 equivalents when the active hydrogen-containing group is an amino group). When the amount of active hydrogen is less than 0.5 equivalent, the drying property, blocking resistance and film strength are insufficient, and when the amount of active hydrogen is more than 2.0 equivalents, the chain extender is unreacted. It remains as it is, and the odor tends to remain on the printed matter. In these production methods, the solvent used is usually an aromatic solvent such as benzene, toluene, xylene, which is well known as a solvent for printing inks; methanol, ethanol, isopropanol, n-
Examples thereof include alcohol solvents such as butanol; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate, and these are used alone or in a mixture of two or more kinds.

The number average molecular weight of the polyurethane of the present invention thus obtained is preferably in the range of 5,000 to 100,000. When the number average molecular weight is less than 5,000, the drying property, blocking resistance, film strength, oil resistance, etc. of the coating agent using this as a vehicle are apt to decrease, while when it exceeds 100,000, the polyurethane resin The viscosity of the solution (binder) tends to increase, and the gloss and coatability of the coating agent tend to deteriorate. The concentration of the resin solid content of the polyurethane resin solution is not particularly limited, but may be appropriately determined in consideration of workability and the like, and is usually 15 to 60% by weight and the viscosity is 50%.
It is practically preferable to adjust the temperature in the range of -100,000 cP / 25 ° C.

The polyurethane having a rosin skeleton obtained in the present invention is used for coating agents, paints, printing inks, adhesives and the like, and is particularly suitable for plastic molded articles. In that case, if necessary, in addition to the polyurethane of the present invention, the following resins may be used in combination as an auxiliary component. Examples thereof include polyurethanes, polyamides, nitrocellulose, polyacrylic acid esters, polyvinyl chlorides, copolymers of vinyl chloride and vinyl acetate, chlorinated polypropylenes and the like other than the present invention.

[0022]

EFFECTS OF THE INVENTION According to the present invention, by using the rosin-modified polymer polyol as a polymer diol component, excellent adhesion and oil resistance to various plastic molded products such as polyester, nylon, polyethylene and polypropylene can be obtained. It is possible to obtain a novel polyurethane having a rosin skeleton, which has excellent properties and boil resistance, and has excellent pigment dispersibility.

Although the reason why the polyurethane of the present invention exhibits the above effects is not clear, the polyurethane comprising the above-mentioned specific polymer polyol uniformly contains a rosin skeleton having a high tackifying effect in its side chain and having a strong hydrophobicity. Therefore, the adhesion, oil resistance and boil resistance are improved, and the affinity between the rosin moiety in the polyurethane molecule and the pigment is large (most of the pigments are surface-treated with rosins).
It is considered that the pigment dispersibility is improved.

[0024]

EXAMPLES The present invention will be described in detail below with reference to production examples, examples and comparative examples, but the present invention is not limited to these examples. Hereinafter, parts and% are based on weight unless otherwise specified.

Production Example 1 A round-bottomed flask equipped with a stirrer, a thermometer, a cooling tube and a nitrogen gas introducing tube was charged with Chinese gum rosin (WG grade, acid value 16).
6.1) 200 parts were charged, heated under a nitrogen stream to be completely melted, and then 108.9 parts of 2,2-bis (4-hydroxyphenyl) propane diglycidyl ether were added with stirring to 140 ° C. Then, by adding 0.058 part of 2-methylimidazole and reacting at 150 ° C. for 5 hours, a hydroxyl value is 113.0 and an acid value is 1.4 KOHm.
g / g, number average molecular weight 993 diol compound (A) 3
08.6 parts were obtained.

Production Example 2 A round bottom flask similar to that used in Production Example 1 was charged with 308.6 parts of a diol compound (A), 313 parts of ε-caprolactone and 0.06 part of dibutyltin laurate, and the mixture was heated to 170 ° C. under a nitrogen stream. A diol having a hydroxyl value of 56.8 KOHmg / g, an acid value of 0.9 KOHmg / g, and a number average molecular weight of 1975, which was obtained by further performing ring-opening polymerization of ε-caprolactone using the diol compound (A) as an initiator by reacting for 5 hours. A compound (B) was obtained.

Example 1 In the same round bottom flask as in Production Example 1, 500 parts of the diol compound (A) obtained in Production Example 1, 500 parts of polybutylene adipate diol having a molecular weight of 2000, and isophorone diisocyanate were used. 267.6 parts of toluene and 316.9 parts of toluene were charged and reacted at 100 ° C. for 6 hours under a nitrogen stream to prepare a prepolymer solution having a free isocyanate content of 2.39%. Then, 734.2 parts of toluene and 1051.1 parts of methyl ethyl ketone were added and diluted, and then 62.9 parts of isophoronediamine, 20.9 parts of di-n-butylamine,
A mixture of 1051.1 parts of isopropyl alcohol was added, and the mixture was reacted at 50 ° C. for 3 hours. The obtained polyurethane resin solution (hereinafter referred to as resin solution A) had a resin solid content concentration of 30% and a viscosity of 640 cP / 25 ° C. The number average molecular weight of the polyurethane resin is 1670.
The rosin content in the resin solid content is 24%.

Example 2 In the same round bottom flask as in Production Example 1, 1000 parts of the diol compound (B) obtained in Production Example 2, 202.3 parts of isophorone diisocyanate and 300.6 of toluene were added. Parts were charged and reacted under a nitrogen stream at 100 ° C. for 6 hours to prepare a prepolymer solution having a free isocyanate content of 2.26%. Then, 687.5 parts of toluene and 988.1 parts of methyl ethyl ketone are added and diluted, and then 49.6 parts of isophoronediamine and 2-hydroxyethylethylenediamine 7.
A mixture of 1 part, 11.5 parts di-n-butylamine and 988.1 parts isopropyl alcohol was added, 50
The reaction was carried out at ℃ for 3 hours. The obtained polyurethane resin solution (hereinafter referred to as resin solution B) has a resin solid content concentration of 30.
%, The viscosity was 2800 cP / 25 ° C. The number average molecular weight of the polyurethane resin is 28600, and the rosin content in the resin solid content is 25%.

Example 3 In the same round bottom flask as in Production Example 1, 500 parts of the diol compound (B) obtained in Production Example 2 and poly (3-methyl-1,5-pentane adipate) having a molecular weight of 2000 were prepared. 500 parts of diol, 202.3 parts of isophorone diisocyanate,
And 300.6 parts of toluene were charged, and 10 was added under a nitrogen stream.
The reaction was carried out at 0 ° C for 6 hours to obtain a free isocyanate content of 2.26.
% Prepolymer solution was prepared. Next, after diluting with 1678.1 parts of methyl ethyl ketone, a mixture of 64.4 parts of isophoronediamine, 5.3 parts of diethanolamine and 989.4 parts of isopropyl alcohol was added, and the mixture was reacted at 50 ° C. for 3 hours. The obtained polyurethane resin solution (hereinafter referred to as resin solution C) had a resin solid content concentration of 30% and a viscosity of 6200 cP / 25 ° C. The number average molecular weight of the polyurethane resin is 66700, and the content of rosins in the resin solid content is 13%.

Comparative Example 1 A round-bottomed flask similar to that used in Preparation Example 1 was charged with 1000 parts of polybutylene adipate diol having a molecular weight of 2000, 200 parts of isophorone diisocyanate, and 300 parts of toluene, and the mixture was heated to 100 ° C. under a nitrogen stream. The reaction was carried out for 6 hours to prepare a prepolymer solution having a free isocyanate content of 2.24%. Then, after diluting by adding 690.1 parts of toluene and 990.1 parts of methyl ethyl ketone, a mixture of 58.2 parts of isophoronediamine, 14.8 parts of di-n-butylamine and 990.1 parts of isopropyl alcohol was added, and 50 The reaction was carried out at ℃ for 3 hours. The obtained polyurethane resin solution (hereinafter referred to as resin solution D) had a resin solid content concentration of 30% and a viscosity of 1000 cP / 25 ° C. The number average molecular weight of the polyurethane resin was 22,000.

Comparative Example 2 To 1000 parts of the polyurethane resin solution D obtained in Comparative Example 1,
Arakawa Chemical Industry Co., Ltd. rosin-based tackifier "Ester gum 105" (softening point 105 ° C, acid value 18, number average molecular weight 1150) 30 parts and toluene 70 parts were added and uniformly dissolved to obtain a resin solution E. Obtained.

(Performance Evaluation) Examples 1 to 3 and Comparative Examples 1 to 1
Each of the polyurethane resin solutions A to E obtained in 2 was used as a binder for printing ink, and the resin performance of each was evaluated. Composition of white ink Titanium white (rutile type) 30 parts Resin solutions A to E obtained in Examples 1 to 3 and Comparative Examples 1 to 50 50 parts Toluene 10 parts Isopropyl alcohol 10 parts White printing ink was prepared by kneading with a squid. To 100 parts of each of these 5 white printing inks, 35 parts of toluene and 15 parts of isopropyl alcohol were added to adjust the viscosity,
Using a simple gravure printing machine equipped with a gravure plate with a plate depth of 30 μm, the discharge-treated surface (hereinafter abbreviated as OPP) of a corona discharge-treated stretched polypropylene film having a thickness of 20 μm, and a corona discharge-treated nylon film having a thickness of 15 μm (NY 40) by printing on the discharge treated surface of 1) and one side of polyethylene terephthalate (PET) having a thickness of 11 μm.
It dried at 50 degreeC and the printing film was obtained.

(Evaluation of Adhesiveness) When cellophane tape was attached to the printing surface of a printing film that had been left for one day and was rapidly peeled off, ◎ -------- the printing film did not come off at all ○ -------- 80% or more of the printed film remained △ -------- 50 to 80% of the printed film remained × ------- 50 It was evaluated that only a printed film of less than% remained. The results are shown in Table 1.

(Preparation of Laminated Film and Performance Evaluation Method) 3 g / m ^{2 of a} 25% solid content polyurethane adhesive was applied to the printing surface of NY and PET printing films.
After coating and drying with the coating amount of 60, it is 60 by a laminator.
A polyethylene film having a thickness of μm was dry laminated to obtain a laminated film. The laminate strength (adhesive strength) of the laminate film thus obtained and the suitability for boiling at 85 ° C. were evaluated as follows. Table 1 shows the evaluation results
Shown in.

Boil Suitability (1) Evaluation by Change of Appearance of Film Laminate film was observed for change in appearance after boiling at 85 ° C. for 30 minutes. 〇 -------- There is no abnormality in the film. △ -------- A small part of the film is delaminated or there is a slight blister, but it occurs. × -------- Part of the film is delaminated or blister is generated. (2) Evaluation by change in laminate strength (adhesive strength) After boiling the laminate film at 85 ° C. for 30 minutes,
T-type peel strength (unit: g / 15 mm) was measured with a peel tester at a speed of 300 mm / min and cut to a width of 15 mm, and compared with the strength before boiling.

(Evaluation of pigment dispersibility) Composition of indigo ink Phthalocyanine blue 10 parts Resin solutions A to E obtained in Examples 1 to 3 and Comparative Examples 1 to 50 50 parts Toluene 10 parts Isopropyl alcohol 10 parts Each mixture was kneaded with a paint shaker to prepare an indigo printing ink, and the fluidity thereof was used to evaluate the pigment dispersibility. 〇 -------- There is liquidity. × -------- No fluidity.

[0037]

[Table 1]

Claims (2)

[Claims] 1. A polyurethane obtained by reacting a high molecular diol, a diisocyanate compound and a chain extender contains a reaction product of 1 molecule of a diepoxy compound and 2 molecules of rosins as a polymer diol component, The content of the reaction product is 3 to 50% by weight in terms of the content of rosins based on the solid content of the produced polyurethane, and the polyurethane has a rosin skeleton. 2. The polyurethane according to claim 1, wherein the number average molecular weight of the reaction product of one molecule of diepoxy compound and two molecules of rosins is 700 to 10,000.