JP5754068B2 - Polyurethane resin aqueous dispersion - Google Patents

Description

  The present invention relates to an aqueous polyurethane resin dispersion particularly suitable for use as an adhesive, and an adhesive using the same. More specifically, the polyurethane has a long tack-free time (open time), can be bonded to a substrate at a lower reactivation temperature than before, and has excellent adhesive strength and heat resistance. The present invention relates to an aqueous resin dispersion and an adhesive using the same.

  In general, when using polyurethane-based aqueous solutions and dispersions to adhere to various base materials such as rubber, leather, metal, polyvinyl chloride (PVC), plastics, foams, fibers, etc. The tack free time (open time) of the agent is very important.

  In order to bond the base material coated with the aqueous dispersion adhesive, after applying the adhesive to the base material, in order to remove moisture and develop adhesive performance, for example, under conditions of about 50 to 60 ° C. A so-called “reactivation process” is required to dry. If the time from the reactivation step to the pasting of the base material coated with the adhesive is too long, there is a problem that the adhesiveness on the surface of the adhesive disappears during the pasting and the adhesive performance cannot be obtained. Adhesive tack-free time (open time) is strongly influenced by the environmental temperature and the surface temperature of the base material during application and bonding, and therefore tack-free when the environment and base material surface temperature are low. Time (open time) tends to be short, and conversely, when these temperatures are high, it tends to be long.

  For this reason, conventionally, various adhesives such as shoes and rubber are less affected by the environmental temperature and the surface temperature of the base material, and the time from reactivation to bonding is sufficient, and tack-free. There has been a strong demand to provide an adhesive having a long time (open time) and excellent adhesive strength and durability.

  A method for producing an aqueous polyurethane resin dispersion is described in U.S. Pat. No. 3,036,998, U.S. Pat. No. 3,756,992, and the like, and is known. Japanese Patent Publication No. 59-30186 describes a polyurethane resin obtained from an amorphous polyester polyol containing a sulfonic acid metal base and a polyisocyanate compound. This publication describes improvements in adhesion, water resistance and the like of a polyurethane resin obtained by the production method coated on a polyethylene terephthalate film. However, the adhesive of the aqueous polyurethane resin dispersion is mainly composed of an aromatic polyester polyol, has a reactivation temperature of 100 ° C. or higher, and requires heat bonding at a high temperature. When used for general adhesion and bonding of rubber, etc., the tack free time (open time) of the adhesive was short, and the substrate could be damaged by heat, so that the sufficient performance was not satisfied.

  Further, Japanese Patent No. 2894494 describes a method for producing an aqueous solution or dispersion of a polyisocyanate polyadduct containing a carboxylate group and / or a sulfonate group as a hydrophilic group. The patent describes that when the adhesive applied to the substrate is reactivated, it can be treated at a low temperature, but the tack-free time (open time), which is important for adhesive application workability, is short, There was a problem that the adhesive performance such as adhesive strength was not fully satisfied.

Problems to be solved by the invention

  Therefore, the object of the present invention is that the tack free time (open time) is longer than that of the conventional type adhesive, for example, the reactivation at a low temperature of about 50 to 60 ° C. is possible, and the adhesive strength, An object of the present invention is to provide an aqueous polyurethane resin dispersion excellent in heat resistance and an adhesive using the aqueous dispersion.

Means for solving the problem

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used the following specific polyurethane resin aqueous dispersion as an adhesive, whereby the adhesive has a long tack-free time, for example, 50 It has been found that it can be reactivated at a low temperature of about ˜60 ° C. and is excellent in adhesive strength and heat resistance, and has completed the present invention.

That is, the present invention comprises (A) an organic polyisocyanate, (B) a polyester polyol containing an aromatic sulfonic acid metal base, (C) an aliphatic polyol having a hydroxyl value of 10 to 350 mgKOH / g, and (D- 1) Polyamine having a molecular weight of 300 or less, and (D-2) ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, which are polyols having a molecular weight of 300 or less, 5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, 3-methyl-1,5-pentanediol, 2-butyl 2-ethyl 1,3 Polyurethane resin aqueous dispersion obtained by reacting propanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, glycerin, trimethylolpropane or pentaerythritol (however, the polyurethane resin (B-1) dicarboxylic acid or ester derivative thereof containing (B-1) an aromatic sulfonic acid metal base , and ( B-2) molecular weight. Polyester polyol obtained by using 300 or less polyol and (B-3) cyclic ester , 55 wt% or more of (C) aliphatic polyol is used in the polyurethane resin solid content, and sulfonic acid metal base is polyurethane 50 to resin solids 700 mmol / kg and contained, the proportion of (A) an organic polyisocyanate with respect to the polyurethane resin solid content is polyurethane resin aqueous dispersion, which is a 8 to 25% by weight,

The present invention also relates to an aqueous adhesive comprising an aqueous polyurethane resin dispersion.

  Next, specific matters necessary for carrying out the present invention will be described below.

The aqueous polyurethane resin dispersion of the present invention comprises (A) an organic polyisocyanate, (B) a polyester polyol containing an aromatic sulfonic acid metal base, (C) an aliphatic polyol having a hydroxyl value of 10 to 350 mgKOH / g, (D-1) a polyamine having a molecular weight of 300 or less and (D-2) ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butane which are polyols having a molecular weight of 300 or less Diol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, 3-methyl-1,5-pentanediol , 2- Polyurethane resin aqueous dispersion obtained by reacting til 2-ethyl 1,3-propanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, glycerin, trimethylolpropane or pentaerythritol (However, n-butylamine is not included as a constituent of the polyurethane resin.) The polyester polyol of (B) is a dicarboxylic acid or ester thereof containing (B-1) an aromatic sulfonic acid metal base. ( B-2) Polyester polyol obtained by using ( B-2) polyol having a molecular weight of 300 or less , and (B-3) cyclic ester, and using the aliphatic polyol of (C) in an amount of 55% by weight or more in the polyurethane resin solid content Sulfonic acid metal base polyurethane Containing 50~700mmol / kg against fat solids, polyurethane resin aqueous dispersion, wherein the proportion of the polyurethane resin solids for (A) an organic polyisocyanate is 8 to 25 wt%.

The organic polyisocyanate (A) used in preparing the aqueous polyurethane resin dispersion of the present invention is a compound represented by the following general formula [1].
R (NCO) n General formula [1]
(However, R in the general formula [1] is an arbitrary organic group, n ≧ 2.)

  As the organic polyisocyanate (A) used in the present invention, any known organic polyisocyanate (A) can be used. Particularly typical examples thereof include, for example, 1,4-tetramethylene diisocyanate, 1,6- Hexamethylene diisocyanate, 1,12-dodecamethylene diisocyanate, cyclohexane-1,3- or 1,4-diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (also known as isophorone diisocyanate; IPDI) Bis- (4-isocyanatocyclohexyl) methane (also known as hydrogenated MDI), 2- or 4-isocyanatocyclohexyl-2'-isocyanatocyclohexylmethane, 1,3- or 1,4-bis- (isocyanatomethyl) ) -Cyclohexane, bis- (4 Isocyanato-3-methylcyclohexyl) methane,

1,3- or 1,4-α, α, α'α'-tetramethylxylylene diisocyanate, 2,4- or 2,6-diisocyanatotoluene, 2,2'-, 2,4'- or Examples include 4,4′-diisocyanatodiphenylmethane (MDI), 1,5-naphthalene diisocyanate, p- or m-phenylene diisocyanate, xylylene diisocyanate or diphenyl-4,4′-diisocyanate.

  Among these, the use of an aromatic diisocyanate compound is particularly desirable from the viewpoint of mechanical strength, and the use of an aliphatic or alicyclic diisocyanate compound is particularly desirable from the viewpoint of durability and light resistance. .

  Moreover, you may use together the polyisocyanate compound exceeding bifunctional in the range which does not inhibit adhesiveness.

  In the present invention, the isocyanate content relative to the solid content of the polyurethane resin is preferably in the range of 8 to 25% by weight. Within such a range, the cohesive strength of the urethane molecules is in a suitable range, the reactivation at a low temperature is favorably performed, and the development of the initial strength is not delayed.

  In the polyester polyol (B) containing an aromatic sulfonic acid metal base used in the present invention, the dicarboxylic acid containing an aromatic sulfonic acid metal base or its ester derivative (B-1) includes Na, K, Li, Examples thereof include metal salts of dicarboxylic acids such as 5-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfophthalic acid, and 5 [4-sulfophenoxy] isophthalic acid containing metal ions such as Ca or ester derivatives thereof.

The molecular weight of 300 or less of the polyol used in the present invention (D -2) is d Ji glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5 -Pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, 3-methyl-1,5-pentanediol, 2-butyl aliphatic diols such as 2-ethyl-1,3-propanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol a, glycerol, trimethylolpropane or pentaerythritol der The

  Furthermore, the polycarboxylic acid not containing a sulfonic acid group or an ester derivative thereof and / or a cyclic ester (B-3) used in the present invention is a polycarboxylic acid not containing a sulfonic acid group or an ester derivative thereof. The following compounds containing no sulfonic acid group, such as terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid Acids, aromatic dicarboxylic acids such as 1,2-bis (phenoxy) ethane-p, p′-dicarboxylic acid and their anhydrides or ester-forming derivatives, aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and Those ester-forming derivatives are exemplified.

  In addition, examples of the aliphatic (alicyclic) dicarboxylic acid include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, maleic anhydride and fumaric acid, and alicyclic such as 1,4-cyclohexanedicarboxylic acid. And dicarboxylic acids and anhydrides or ester-forming derivatives thereof. Examples of the polyfunctional component include polycarboxylic acids such as trimellitic acid, pyromellitic acid, and cyclohexanetricarboxylic acid, and anhydrides or ester-forming derivatives thereof.

  Furthermore, ε-caprolactone, γ-valerolactone, and the like are exemplified as the cyclic ester in (B-3) used in the present invention. Among these cyclic esters, ε-caprolactone is preferable.

  In general, when applied to various substrates, the tack-free time (open time) is considered to be 3 minutes or more from the viewpoint of work, the adhesive strength immediately after bonding is high, and the heat resistance is also excellent. It is requested. Usually, an aqueous polyurethane resin dispersion designed to increase the tack-free time (open time) has low cohesiveness, crystallinity, and initial heat resistance, and often causes a decrease in adhesive strength.

  On the other hand, the polyester polyol (B) containing an aromatic sulfonic acid metal base has an aromatic ring in the main chain, so that it imparts rigidity to the polyurethane molecule and at the same time a cohesive force between the urethane molecular chains from the three-dimensional structure. There is a property to suppress a part. For this reason, by introducing the polyester polyol containing the aromatic sulfonic acid metal base into the polyurethane molecule, not only the tack free time (open time) as an adhesive is lengthened, but also the cohesive force and rigidity are simultaneously improved. It can be realized.

  Furthermore, the polyurethane resin has a property that a soft segment made of a polyol having a high molecular weight is localized at the interface. Therefore, when a polar (hydrophilic = sulfonic acid metal salt) group is present in the polyol, which is a soft segment as an essential component in the present invention, the affinity for a polar base material such as vinyl chloride (PVC) or metal is increased and adhesion is improved. Improvement can be expected.

  Moreover, since the polyester polyol (B) containing an aromatic sulfonic acid metal base used in the present invention is an ester of an aromatic acid, it has excellent hydrolysis resistance and has been a problem in aqueous urethane resins. It is also effective in improving storage stability and durability. In addition, a low molecular polyol is arbitrarily selected, and a lactone monomer having good water resistance is further introduced into the polyester polyol (B) containing the aromatic sulfonic acid metal base, whereby the aqueous polyurethane resin dispersion is obtained. It is possible to arbitrarily adjust water resistance, heat resistance, cohesive force and the like.

  The content of the polyester polyol (B) containing the aromatic sulfonic acid metal base used in the present invention is also related to the content of the sulfonic acid metal base that is a hydrophilic group, and is 5 to 5% of the polyurethane resin solid content. A range of 30% by weight is preferable, and the content of the sulfonic acid metal base is preferably 70 to 250 mmol / kg based on the solid content of the polyurethane resin. If the content of the sulfonic acid metal base is within such a range, the hydrophilic group amount is suitable, the particles are stabilized and the particles are not aggregated, the concentration is easily increased, and the water resistance is also good. .

  In preparing the aqueous polyurethane resin dispersion of the present invention, as the aliphatic polyol (C) to be used, polyester polyol is mainly used, but polyether polyol, polycarbonate polyol, etc., or a single or a mixture thereof. Copolymers may also be used.

  The aliphatic polyester polyol is prepared by reacting various known and conventional polyol compounds with various known and conventional polycarboxylic acids or various reactive derivatives thereof by various known and conventional methods. .

  Here, as typical polyol compounds, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl Aliphatic diols such as 1,3-propanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, alicyclic diols such as hydrogenated bisphenol A, and glycerin and trimethylol as polyfunctional components Propane, and a polyol such as pentaerythritol.

  On the other hand, examples of typical digalbonic acids include, for example, succinic acid, succinic anhydride, adipic acid, suberic acid, azelaic acid, sebacic acid, dimer acid, 1,4-cyclohexanedicarboxylic acid. Examples thereof include aliphatic dicarboxylic acids such as acids. Further, it may be a polyester polyol to which a cyclic lactone such as ε-caprolactone or γ-valerolactone is added.

  In addition, specific examples of the polyether polyol that can be used in the present invention include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, in the presence of a compound having an active hydrogen atom (reactive hydrogen atom). Examples thereof include polymers obtained by ring-opening polymerization of various three-membered or four-membered ether compounds such as tetrahydrofuran or epichlorohydrin, or a mixture of two or more thereof. Specific examples of the polyether diol include polyethylene polyol, polypropylene polyol, and polytetramethylene polyol. Further, a polyether monool partially blocked with a monoalcohol such as methanol or butanol may be used within a range that does not hinder the increase in the molecular weight.

  In addition, specific examples of polycarbonate polyols that can be used in the present invention include, for example, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol, or Examples thereof include a reaction product of a diol such as polytetramethylene glycol and a cyclic carbonate such as dimethyl carbonate represented by dimethyl carbonate or ethylene carbonate.

The hydroxyl value of the aliphatic polyol (C) used in the present invention is preferably in the range of 10 to 350 mgKOH / g. The “hydroxyl value” referred to here is the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group when 1 g of a sample is acetylated.

  In the present invention, the content of the aliphatic polyol (C) in the polyurethane resin solid content is preferably 55% by weight or more, and more preferably 55 to 85% by weight. Sex etc. can be given. In addition, if the content of the aliphatic polyol (C) in the solid content of the polyurethane resin is within this range, for example, a soft segment (aliphatic polyol in the polyurethane resin component that is thermally melted at a temperature of about 50 to 60 ° C. ) Since the number of sites increases, reactivation of the bonding surface becomes active, and high bonding performance can be expressed immediately after bonding.

  Next, the polyamine and / or polyol (D) having a molecular weight of 300 or less used in the present invention is a polyamine having a total number of amine groups and hydroxyl groups in the molecule of 2 or more and having a molecular weight of 300 or less and / or Or a polyol.

  Examples of particularly typical polyamines having 2 or more functional groups and a molecular weight of 300 or less used in the present invention include, for example, 1,2-diaminoethane, 1,2- or 1,3-diaminopropane. 1,2- or 1,3- or 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, piperazine, N, N′-bis- (2-aminoethyl) piperazine, 1 -Amino-3-aminomethyl-3,5,5-trimethyl-cyclohexane (isophoronediamine), bis- (4-aminocyclohexyl) methane, bis- (4-amino-3-butylcyclohexyl) methane, 1,2- 1,3- or 1,4-diaminocyclohexane or diamines such as 1,3-diaminopropane, diethylenetriamine, triethylenetetra Polyamines such as lamin, hydrazine derivatives such as hydrazine or adipic acid dihydrazide, sulfonic acid diamines described in Japanese Patent Publication No. 49-36693 and Canadian Patent No. 928,323, or N- (2-aminoethyl) Sodium 2-aminopropionate can also be used.

In addition, as the polyol having 2 or more functional groups and a molecular weight of 300 or less used in the present invention, in the polyester polyol (B) containing an aromatic sulfonic acid metal base, the above-described polyol having a molecular weight of 300 or less ( D -2) and was similar polyol to that described can be used.

  Furthermore, an amino alcohol having an amino group and an alcoholic hydroxyl group in the molecule and having a total number of functional groups of 2 or more and a molecular weight of 300 or less used in the present invention can be used as such a compound. Examples include ethanolamine, N-methyldiethanolamine, propanolamine, N-methyldiisopropanolamine, N-ethyldiethyleneamine, N-ethyldiisopropanolamine, aminoethylethanolamine, and diethanolamine.

  By using a polyamine and / or polyol having a functional group number of 2 or more and a molecular weight of 300 or less, the cohesive strength of the polyurethane resin can be increased, and the initial heat resistance can be improved by increasing the molecular weight.

  Examples of particularly typical organic solvents used in preparing the aqueous polyurethane resin dispersion of the present invention include benzene, toluene, ethyl acetate, acetone, methyl ethyl ketone, diethyl ether, tetrahydrofuran, methyl acetate, acetonitrile, Examples include chloroform, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane, tetrachloroethylene, or N-methylpyrrolidone, and these can be used alone or as a mixed solvent. Among these, it is particularly preferable to use acetone or methyl ethyl ketone as a solvent having high solubility for the polyurethane resin.

  An emulsifier may be used in combination when preparing the aqueous polyurethane resin dispersion of the present invention. Typical emulsifiers usable in the present invention include, for example, polyoxyethylene polyoxypropylene glycol ether type, polyoxyethylene nonylphenyl ether type, polyoxyethylene octylphenyl ether type, polyoxyethylene lauryl ether type, polyoxyethylene Nonionic emulsifiers such as ethylene laurate type, polyoxyethylene alkyl ether type, sorbitan derivative type, polyoxyethylene polycyclic phenyl ether type, anionic emulsifiers such as alkylbenzene sulfonate type and dialkyl succinate sulfonate type, cation System emulsifiers, and zwitterionic emulsifiers.

  Among these emulsifiers, nonionic emulsifiers and / or anionic emulsifiers are suitable, and the addition amount thereof is preferably 10% by weight or less based on the solid content relative to the polyurethane resin. When these emulsifiers are used, it is desirable to emulsify and disperse them after adding them to the polyurethane resin solution before the emulsifying and dispersing step or the prepolymer in which the isocyanate groups remain, but they may be added after the end of the emulsifying and dispersing step.

  If necessary, a urethanization catalyst can be used in preparing the aqueous polyurethane resin dispersion of the present invention. Examples of the urethanization catalyst that can be used in the present invention include various nitrogen-containing compounds such as triethylamine, triethylenediamine, or N-methylmorpholine, various metal salts such as potassium acetate, zinc stearate, or tin octylate, and dibutyl. And various organometallic compounds such as tin dilaurate.

  As the aqueous adhesive containing the polyurethane resin aqueous dispersion of the present invention, the polyurethane resin alone may be used, or an aqueous dispersion other than the urethane resin represented by SBR latex resin and acrylic emulsion may be used in combination. In this case, the ratio (polyurethane resin solid content / total solid content) is preferably 1% by weight or more, more preferably 10% by weight or more.

  Furthermore, auxiliary materials and additives used for ordinary adhesives within the range not inhibiting the cohesiveness of the adhesive of the present invention, such as plasticizers, tackifiers (rosin resins, rosin ester resins, terpene resins, terpene phenols) Resins, petroleum resins, coumarone resins, etc.), fillers, pigments, thickeners, antioxidants, ultraviolet absorbers, surfactants, flame retardants, and the like.

  The aqueous polyurethane resin dispersion of the present invention can be used alone, but a bifunctional or higher functional compound such as a polyisocyanate compound can also be used as a crosslinking agent. Examples of the bifunctional or higher functional crosslinking agent that can be used in the present invention include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 4,4′-diisocyanatodiphenylmethane (MDI), xylylene diisocyanate, and isophorone. Polyisocyanate compounds composed of trimers such as diisocyanates, or low molecular active hydrogen such as the polyisocyanate compounds and ethylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, polyoxyethylene glycol, long chain higher alcohols, etc. An isocyanate group-terminated compound comprising a compound or the like can be mentioned.

As described above, the embodiment of the present invention includes (A) an organic polyisocyanate, (B) a polyester polyol containing an aromatic sulfonic acid metal base, and (C) a fat having a hydroxyl value of 10 to 350 mgKOH / g. Group polyol, (D-1) a polyamine having a molecular weight of 300 or less, and (D-2) ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, which is a polyol having a molecular weight of 300 or less, 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, 3-methyl-1,5 -Pentanediol, 2-bu Polyurethane resin aqueous dispersion obtained by reacting ru-2-ethyl 1,3-propanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, glycerin, trimethylolpropane or pentaerythritol (However, n-butylamine is not included as a constituent of the polyurethane resin.) The polyester polyol of (B) is a dicarboxylic acid or ester thereof containing (B-1) an aromatic sulfonic acid metal base. ( B-2) Polyester polyol obtained by using ( B-2) polyol having a molecular weight of 300 or less , and (B-3) cyclic ester, and using the aliphatic polyol of (C) in an amount of 55% by weight or more in the polyurethane resin solid content Sulfonic acid metal base The polyurethane resin aqueous dispersion is characterized by containing 50 to 700 mmol / kg based on the solid content, and the proportion of the (A) organic polyisocyanate used based on the solid content of the polyurethane resin is 8 to 25% by weight. is there.

  Another embodiment of the present invention is obtained by using a polyamine and / or polyol having a total number of functional groups of amine groups and hydroxyl groups in the molecule of (D) of 2 or more and a molecular weight of 300 or less. This relates to the aqueous polyurethane resin dispersion.

  As another aspect of the present invention, (B) the polyester polyol is (B-1) a dicarboxylic acid containing an aromatic sulfonic acid metal base or an ester derivative thereof, (B-2) having a molecular weight of 300 or less. The present invention relates to each of the above polyurethane resin aqueous dispersions, which is a polyester polyol obtained by using a polyol and (B-3) a polycarboxylic acid not containing a sulfonic acid group or an ester derivative thereof and / or a cyclic ester.

  Another aspect of the present invention relates to the aqueous polyurethane resin dispersion in which the cyclic ester is ε-caprolactone.

    As another aspect of the present invention, the polyurethane resin aqueous dispersion containing 50 to 700 mmol / kg of a sulfonic acid metal base relative to the solid content of the polyurethane resin is applied.

  Another aspect of the present invention relates to an aqueous adhesive comprising the above polyurethane resin aqueous dispersion.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to these Examples. In the following, all parts and% are based on weight unless otherwise specified. In addition, about the performance evaluation method regarding the adhesive agent of the polyurethane resin aqueous dispersion of this invention, it is as follows.

[Tack Free Time (Open Time) Evaluation Method]
The adhesive of the polyurethane resin aqueous dispersion, using a brush 1 mm (thickness) × 20 mm (width) × 300 mm (length) 100 g / m ² was applied to the PVC sheet, hot-air circulation drying for 6 minutes at 50 ° C. Reactivate it in the machine. The adhesive tack on the surface of the base material taken out from the dryer disappeared, and the time when the adhesive surfaces did not adhere even if they were pressed together with a rubber roller was measured, and the tack free time (open time) was determined.

[Evaluation method of contactability]
After bonding together the PVC sheets coated with the polyurethane resin aqueous dispersion adhesive, peel the adhesive surface by hand after 1 minute, observe the degree of cohesive failure of the adhesive, and contact from the state of biting between the adhesive The quality of the was evaluated. In addition, the evaluation criteria of Table 2 and Table 3 were performed according to the following.
◯: A state where the resistance to peeling is strong and the adhesive on both sides of the substrate stretches when peeled.
Δ: Peeling resistance is weak, and the adhesive on both sides of the substrate peels without stretching.
X: The state which does not have a peeling resistance feeling and peels easily.

[Evaluation method of initial adhesive strength]
Each adhesive was applied to 100 g / m ^{2 on two} PVC sheets in the same manner as in the case of tack free time (open time). Reactivate in a hot air circulating dryer at 50 ° C for 6 minutes. The adhesive surfaces of the PVC base material taken out from the dryer were pressed together with a rubber roller and bonded together, and the peel strength after 2 minutes from the bonding was measured with a digital gauge.

[Method of evaluating peel strength over time]
About the bonding test piece produced like the evaluation method of initial stage adhesive strength, the peeling strength for 2 hours and 1 day after bonding was measured with the tensile tester. The 180 degree peel strength was determined at a pulling speed of 100 mm / min.

[Evaluation method for heat-resistant creep]
A bonded test piece produced in the same manner as the initial adhesive strength evaluation method was cured at room temperature for 3 days. A 1 kg weight was hung on the test piece, placed in a hot air circulating dryer at 70 ° C. for 30 minutes, and a 180 ° creep test was performed. The distance (mm) at which the 100 mm marked line was separated or the time when the weight dropped was measured.

<< Reference Example> Preparation Method of Polyester Polyol (B) Containing Aromatic Sulfonate Metal Base While introducing nitrogen gas into a reaction vessel equipped with a thermometer, nitrogen gas introduction tube, and stirrer, 5-sulfosodium isophthalate 1480 parts of dimethyl acid (DMS), 1240 parts of 1,6-hexanediol, and 0.5 part of dibutyltin oxide are added, and the temperature in the reaction vessel is 180 to 190 ° C. so that the top temperature is 60 to 70 ° C. The transesterification was performed until the acid value became 1 mgKOH / g or less, and then the reaction was carried out at 210 ° C. for 2 hours to obtain a polyester polyol (1) having a hydroxyl value of 240 mgKOH / g and an acid value of 0.3 mgKOH / g. Furthermore, 2280 parts of ε-caprolactone was added to the polyester polyol (1) and subjected to a ring-opening polymerization reaction at 180 ° C. for 3 hours to obtain a polyester polyol (2) having a hydroxyl value of 120 mgKOH / g and an acid value of 0.3 mgKOH / g. . The results are shown in Table 1 as a reference example.

Reference Example 1 Polyester polyol (1) 50 parts of N-methyl-2-pyrrolidone (abbreviation NMP) 100 parts are added and sufficiently stirred and dissolved, 71 parts of isophorone diisocyanate (abbreviation IPDI) is added and reacted at 80 ° C. for 2 hours. I let you. Next, 204 parts of methyl ethyl ketone (abbreviated as MEK) was added and cooled to 60 ° C., and then 5 parts of hexamethylene diisocyanate (abbreviated as HDI), butylene adipate which is a polyester composed of 1,4-butylene glycol and adipic acid (hydroxyl value = 56 mgKOH / 330 parts of g) were added and the reaction was carried out at 80 ° C. After that, when the isocyanate value became 0.85% or less, it was cooled to 40 ° C., 460 parts of water was added and sufficiently stirred and mixed, and then 63 parts of 10% piperazine aqueous solution (95 equivalent% as amine group with respect to residual isocyanate group) Was added and emulsified and dispersed. The obtained emulsion was desolvated to obtain an aqueous dispersion having a nonvolatile content of 40%.

After adding 1 part of SN-Thickener A-812 (manufactured by San Nopco Co., Ltd.) to 100 parts of the obtained aqueous dispersion to increase the viscosity, an isocyanate crosslinking agent CR-60N (Dainippon Ink Co., Ltd.) that can be dispersed in water. The adhesive was adjusted by adding 5 parts of Chemical Industry Co., Ltd. Next, 100 g / m ^{2 of} the adjusted adhesive was applied to two PVC sheets with a brush, and then the adhesive surfaces were bonded together to evaluate each adhesive performance. The evaluation results are shown in Table 2. The adhesive of the present invention has a long tack-free time and is excellent in adhesive strength.

Example 2
30 parts of polyester polyol (2) was added with 60 parts of methyl ethyl ketone and dissolved with sufficient stirring. 34 parts of isophorone diisocyanate and 4 parts of hexamethylene diisocyanate were added and reacted at 80 ° C. for 3 hours. Next, 95 parts of methyl ethyl ketone was added, and after cooling to 60 ° C., 5 parts of 1,4-butylene glycol and 160 parts of butylene adipate (hydroxyl value = 37 mgKOH / g) which is a polyester composed of 1,4-butylene glycol and adipic acid The reaction was carried out at 80 ° C. Thereafter, when the isocyanate value became 0.79% or less, the mixture was cooled to 40 ° C., 280 parts of water was added and sufficiently stirred and mixed, and then 29.7 parts of 10% aqueous piperazine solution (95 equivalents as amine groups with respect to the remaining isocyanate groups). %) Was added and emulsified and dispersed. The obtained emulsion was desolvated to obtain an aqueous dispersion having a nonvolatile content of 50%.

After adjusting the adhesive agent in the same manner as in Reference Example 1 for the obtained aqueous dispersion, the adhesive surfaces were bonded to each other and each adhesive performance was evaluated. The evaluation results are shown in Table 2. The adhesive of the present invention has a long tack-free time and excellent initial adhesive strength.

Example 3
160 parts of butylene adipate (hydroxyl value = 37 mg KOH / g), which is a polyester composed of 1,4-butylene glycol and adipic acid, and 5 parts of 1,4-butylene glycol are added with 60 parts of methyl ethyl ketone and sufficiently stirred to dissolve, 13 parts of isophorone diisocyanate. And 23.5 parts of hexamethylene diisocyanate was added and reacted at 80 ° C. for 3 hours. Next, 100 parts of methyl ethyl ketone was added and cooled to 60 ° C., and then 40 parts of polyester polyol (2) was added and reacted at 80 ° C. Thereafter, when the isocyanate value became 0.98% or less, the mixture was cooled to 40 ° C., 280 parts of water was added and mixed by stirring, and then 38.5 parts of 10% aqueous piperazine solution (95 equivalent% as amine groups with respect to the remaining isocyanate groups). ) To make it aqueous. The obtained emulsion was desolvated to obtain an aqueous dispersion having a nonvolatile content of 50%.

After adjusting the adhesive agent in the same manner as in Reference Example 1 for the obtained aqueous dispersion, the adhesive surfaces were bonded to each other and each adhesive performance was evaluated. The evaluation results are shown in Table 2. The adhesive of the present invention has a long tack-free time, and is excellent in adhesive strength, heat-resistant creep and the like.

<< Comparative Example 1 >>
10% piperazine aqueous solution of Example 3 was mixed with 10% piperazine and n-butylamine aqueous solution (piperazine / n-butylamine = 9/1 amine equivalent ratio) 39.9 parts (95 equivalents as amine groups with respect to the remaining isocyanate groups). %) Was used to carry out the same synthesis as in Example 3 except that the chain was elongated to obtain an aqueous dispersion having a nonvolatile content of 50%.

After adjusting the adhesive agent in the same manner as in Reference Example 1 for the obtained aqueous dispersion, the adhesive surfaces were bonded to each other and each adhesive performance was evaluated. The evaluation results are shown in Table 2, but were inferior in contact property, adhesive strength, heat-resistant creep and the like.

<< Comparative Example 2 >>
100 parts of polyester polyol (2) and 20 parts of butylene adipate (hydroxyl value = 37 mgKOH / g), which is a polyester composed of 1,4-butylene glycol and adipic acid, are added with 100 parts of methyl ethyl ketone and sufficiently stirred to dissolve, 30 parts of isophorone diisocyanate. And reacted at 80 ° C. for 3 hours. Thereafter, when the isocyanate value became 0.71% or less, the mixture was cooled to 40 ° C., 450 parts of water was added and stirred and mixed, and then 17.3 parts of a 10% piperazine aqueous solution (95 equivalent% as an amine group with respect to the remaining isocyanate group). ) To make it aqueous. The obtained emulsion was desolvated to obtain a translucent aqueous dispersion having a nonvolatile content of 30%.

After adjusting the adhesive agent in the same manner as in Reference Example 1 for the obtained aqueous dispersion, the adhesive surfaces were bonded to each other and each adhesive performance was evaluated. Although the evaluation results are shown in Table 2, the tack-free time is long, but there is no contact property, the adhesive strength does not increase over time, the heat resistant creep is inferior, and a practical level cannot be obtained. It was.

<< Comparative Example 3 >>
160 parts of butylene adipate (hydroxyl value = 37 mgKOH / g), which is a polyester composed of 1,4-butylene glycol and adipic acid, and 5 parts of 1,4-butylene glycol are added with 52 parts of methyl ethyl ketone and sufficiently stirred to dissolve, 13 parts of isophorone diisocyanate. And 23.5 parts of hexamethylene diisocyanate was added and reacted at 80 ° C. for 3 hours. Next, 87 parts of methyl ethyl ketone was added, and after cooling to 60 ° C., 7 parts of polyester polyol (2) was added and reacted at 80 ° C. Thereafter, when the isocyanate value became 1.99% or less, the mixture was cooled to 40 ° C., 245 parts of water was added and mixed by stirring, and then 67.5 parts of 10% piperazine aqueous solution (95 equivalent% as amine groups with respect to the remaining isocyanate groups) ) Was added and emulsified and dispersed, but stable particles were not obtained and gelled after solvent removal, which was not practical.

<< Comparative Example 4 >>
160 parts of butylene adipate (hydroxyl value = 37 mgKOH / g), which is a polyester composed of 1,4-butylene glycol and adipic acid, and 6 parts of 1,4-butylene glycol are added with 70 parts of methyl ethyl ketone and sufficiently stirred to dissolve, and 75 parts of isophorone diisocyanate. And reacted at 80 ° C. for 3 hours. Next, 119 parts of methyl ethyl ketone was added and cooled to 60 ° C., and then 40 parts of polyester polyol (2) was added and reacted at 80 ° C. Thereafter, when the isocyanate value became 3.13% or less, the mixture was cooled to 40 ° C., 330 parts of water was added and stirred and mixed, and then 143.3 parts of a 10% aqueous solution of piperazine (95 equivalent% as an amine group with respect to the remaining isocyanate group). ) To make it aqueous. The obtained emulsion was desolvated to obtain an aqueous dispersion having a nonvolatile content of 50%.

After adjusting the adhesive agent in the same manner as in Reference Example 1 for the obtained aqueous dispersion, the adhesive surfaces were bonded to each other and each adhesive performance was evaluated. As shown in Table 3, this product was inferior in contact property, adhesive strength and heat-resistant creep.

<< Comparative Example 5 >>
160 parts of butylene adipate (hydroxyl value = 22 mgKOH / g), which is a polyester composed of 1,4-butylene glycol and adipic acid, is added with 138 parts of methyl ethyl ketone and sufficiently stirred and dissolved, and then 12 parts of hexamethylene diisocyanate is added for 3 hours at 80 ° C. Reacted. Next, 60 parts of methyl ethyl ketone was added, and after cooling to 60 ° C., 30 parts of polyester polyol (2) was added and reacted at 80 ° C. Thereafter, when the isocyanate value became 0.16% or less, the mixture was cooled to 40 ° C., 280 parts of water was added and mixed with stirring, and then 6.4 parts of a 10% piperazine aqueous solution (95 equivalent% as an amine group with respect to the remaining isocyanate group). ) To make it aqueous. The obtained emulsion was desolvated to obtain an aqueous dispersion having a nonvolatile content of 50%.

After adjusting the adhesive agent in the same manner as in Reference Example 1 for the obtained aqueous dispersion, the adhesive surfaces were bonded to each other and each adhesive performance was evaluated. As shown in Table 3, this product had no contact properties and was inferior in adhesive strength and heat-resistant creep.

<< Comparative Example 6 >>
360 parts of butylene adipate (hydroxyl value = 56 mg KOH / g) which is a polyester composed of 1,4-butylene glycol and adipic acid and 2 parts of 1,4-butylene glycol were uniformly melted at 80 ° C., and 15 parts of isophorone diisocyanate and hexa 30 parts of methylene diisocyanate was added and stirring was continued at 80 ° C. for 4 hours. Next, when the isocyanate value became 0.91% or less, the temperature was cooled to 50 ° C., and then 800 parts of acetone was slowly added, and N- (2-aminoethyl) -2-aminoethanesulfonic acid aqueous solution (concentration) 50%) 22.9 parts (90 equivalent% as amine groups to the remaining isocyanate groups) is added. Thereafter, 500 parts of water was slowly added to carry out emulsification and dispersion, and the solvent was removed to obtain a moisture-respecting body having a nonvolatile content of 40%.

After adjusting the adhesive agent in the same manner as in Reference Example 1 for the obtained aqueous dispersion, the adhesive surfaces were bonded to each other and each adhesive performance was evaluated. As shown in Table 3, this product had a short tack-free time and was inferior in heat-resistant creep.

"Comparative Example 7" butylene adipate polyester consisting of 1,4-butylene glycol and adipic acid of Reference Example 1 (hydroxyl value = 56mgKOH / g), butylene consisting of 1,4-butylene glycol and isophthalic acid isophthalate ( Synthesis was performed in the same manner as in Reference Example 1 except that the hydroxyl value was changed to 56 mgKOH / g) to obtain an aqueous dispersion having a nonvolatile content of 50%.

After adjusting the adhesive agent in the same manner as in Reference Example 1 for the obtained aqueous dispersion, the adhesive surfaces were bonded to each other and each adhesive performance was evaluated. As shown in Table 3, this product had a high thermal activation temperature and poor adhesive strength after bonding.

Effect of the invention

  When the polyurethane resin aqueous dispersion of the present invention is prepared to increase the tack-free time (open time) in the prior art, the initial adhesive strength and the temporal adhesive strength are low, and the durability such as heat resistance is not sufficient. It is possible to provide an adhesive that can increase the tack-free time (open time) in manual work and factory lines, and can provide an adhesive having excellent adhesive strength and durability. Suitable for base materials such as film, metal, foam, rubber, fiber, various plastics.

Claims (2)

(A) an organic polyisocyanate, (B) a polyester polyol containing an aromatic sulfonic acid metal base, (C) an aliphatic polyol having a hydroxyl value of 10 to 350 mgKOH / g, and (D-1) having a molecular weight of 300 or less. Polyamine and (D-2) ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, which are polyols having a molecular weight of 300 or less, , 6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, 3-methyl-1,5-pentanediol, 2-butyl 2-ethyl 1,3 -Propaneio 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, glycerin, trimethylolpropane or pentaerythritol obtained by reacting with an aqueous polyurethane resin dispersion (provided that the polyurethane resin is constituted) (B-1) a dicarboxylic acid or an ester derivative thereof containing an aromatic sulfonic acid metal base , and ( B-2) a molecular weight of 300 or less. And (B-3) a polyester polyol obtained by using a cyclic ester , the aliphatic polyol of (C) is used in an amount of 55% by weight or more in the polyurethane resin solid content, and the sulfonic acid metal base is used as a polyurethane resin solid. 50-700 mmol per minute kg containing polyurethane resin aqueous dispersion, wherein the proportion of (A) an organic polyisocyanate with respect to the polyurethane resin solid content is 8 to 25 wt%.
After reacting (A) an organic polyisocyanate, (B) a polyester polyol containing an aromatic sulfonic acid metal base, and (C) an aliphatic polyol having a hydroxyl value of 10 to 350 mgKOH / g, (D-2 ) Ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neoles, which are polyols having a molecular weight of 300 or less Pentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, 3-methyl-1,5-pentanediol, 2-butyl 2-ethyl 1,3-propanediol, 1,4 -Cyclohexanedi , 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, glycerin, trimethylolpropane or pentaerythritol, and (D-1) a polyurethane resin obtained by adding and reacting a polyamine having a molecular weight of 300 or less. An aqueous dispersion (however, it does not contain n-butylamine as a constituent of the polyurethane resin), and the polyester polyol of (B) is (B-1) a dicarboxylic acid containing an aromatic sulfonic acid metal base or The ester derivative , ( B-2) a polyol having a molecular weight of 300 or less , and (B-3) a polyester polyol obtained by using a cyclic ester , and 55% by weight of the aliphatic polyol of (C) in the polyurethane resin solid content Containing sulfonic acid metal base Production of an aqueous polyurethane resin dispersion comprising 50 to 700 mmol / kg of the solid content of the resin and the use ratio of (A) the organic polyisocyanate based on the solid content of the polyurethane resin is 8 to 25% by weight. Method.