JP7115809B2 - Aqueous adhesive resin composition for olefin substrates - Google Patents

Description

TECHNICAL FIELD The present invention relates to a self-emulsifying emulsion that exhibits good adhesion performance to olefinic resin substrates such as polyethylene and polypropylene.

Techniques for adhering substrates with low surface energy such as polyethylene and polypropylene have been studied for a long time, and it is known that it is not easy to design adhesives with high adhesion performance to these materials. As a technique for exhibiting good adhesion to these low surface energy substrates, a technology has been proposed in which the surface of the adherend is pretreated by corona discharge, plasma treatment, etc. to increase the surface energy before bonding. It is While these techniques are effective techniques, they require expensive equipment and increase power consumption.

On the other hand, products using olefin-based materials such as polyethylene and polypropylene have been increasing in recent years for various purposes ranging from everyday household goods to various industrial uses. Especially for in-vehicle applications, mounting of molding materials made of polypropylene is being actively pursued due to the trend toward weight reduction of automobiles. Under these circumstances, in recent years, more effective adhesives than ever before have been developed. This is also described in P139 of Non-Patent Document 1, "2.1 Current State of Adhesive Technology". Specific examples include Patent Document 1 and Patent Document 2. In addition, recently, due to work environment problems, the conventional organic solvent-based adhesives are being changed to more environment-friendly water-based adhesives. Examples can be seen in Patent Documents 3 to 5, for example.

Japanese Patent Application Laid-Open No. 2012-197388 Japanese Patent Application Laid-Open No. 2013-95873 Japanese Patent Application Laid-Open No. 2005-220153 Japanese Patent Application Laid-Open No. 2001-152119 Japanese Patent Application Laid-Open No. 2002-146315

J.Jpn.Soc.Colour MaJ.Jpn.Soc.ColourMater., 87 [4], 139-144 (2014)

In general, for emulsions in which polymers are dispersed in water, there are forced emulsification-type emulsions that use surfactants (emulsifiers) in combination, and self-emulsification, in which hydrophilic polar groups are introduced into the polymer chains to impart emulsifying functions to the polymers themselves. There is a type emulsion. Emulsifiers are extremely useful for stably dispersing polymers that do not have a self-emulsifying function in water. It remains and adversely affects adhesion. This fact is also described in the prior art of Patent Document 5. In Patent Document 3, it is described in paragraph 0116 and Examples that the polyolefin resin composition, which is the main component, is made water-based with a surfactant (emulsifier). Further, in Patent Document 4 as well, it is described in an embodiment of the invention that an acrylic resin, which is the main component of an adhesive, is subjected to emulsion polymerization in the presence of an emulsifier. In Patent Document 5, the polyurethane resin to be blended is an anionic self-emulsifying urethane resin, while the tackifier blended together is dispersed in water by an emulsifier. and paragraph 0019. It is preferable that the acrylic resin, which is the main component, is emulsion polymerized in the presence of a surfactant. What may be done is described in paragraphs 0024 to 0029 in the same inventive embodiment.

Affinity between the adherend and the adhesive resin is a major factor that affects the adhesive performance of the adhesive resin. Typical examples of materials showing affinity for substrates with low surface energy such as polyethylene and polypropylene include silane-based and fluorine-based compounds such as silicone resins and Teflon. Other examples include compounds having a long-chain hydrocarbon group and compounds having an olefin skeleton itself. In fact, in Patent Document 1, a curable resin having a crosslinkable silicon group in the molecule or an alkylalkoxy or arylalkoxylsilane compound is used as a reactive diluent, and in Patent Document 2, a (meth)acrylic resin in which the alkyl group has 10 or more carbon atoms. Patent Document 3 clearly states that acid alkyl ester monomers and chlorinated polyolefins are contained as active ingredients, and modified polyolefin resins are contained as active ingredients. However, these materials, which have a high affinity for olefin base materials, are highly hydrophobic and are not compatible with water. Therefore, when making them water-based, they are forced to emulsify by blending an emulsifier, or they are self-emulsified by introducing hydrophilic polar groups through a modification reaction. There is a need. As mentioned above, the addition of emulsifiers adversely affects the adhesion performance of the adhesive. On the other hand, the introduction of hydrophilic polar groups into the self-emulsification formulation, although localized, introduces a hydrophilic site with a high affinity for water into the molecule, which increases the polarity of the molecule as a whole, resulting in olefinic adhesion. Affinity with the body is reduced, and as a result, the original good adhesiveness is lost.

In view of such problems, the present invention uses an adhesive component that has a high affinity with the olefinic material of the adherend without using any emulsifier and without introducing a hydrophilic polar group by a modification reaction. It is an object of the present invention to provide a self-emulsifying emulsion stably dispersed in water and having excellent storage stability, adhesiveness, adhesiveness and water resistance.

In order to achieve the above object, the present inventors have made intensive studies and have proposed the following invention.

That is, the present invention contains a modified polyurethane resin (component A) having an anionic functional group, a polypropylene resin (component B) having no hydrophilic polar group, and a tackifier (component C), and the following (1) and a self-emulsifying emulsion that satisfies (2).
(1) A modified polyurethane resin (component A) having an anionic functional group is dispersed in water without the presence of an emulsifier. (2) Dispersion particles composed of a modified polyurethane resin (component A) having an anionic functional group. Contains a polypropylene resin (component B) that does not have a hydrophilic polar group and a tackifier (component C)

The polypropylene resin (component B) having no hydrophilic polar group is in the range of 20 parts by weight or more and less than 70 parts by weight with respect to 100 parts by weight of the modified polyurethane resin (component A) having an anionic functional group. is preferred.

The tackifier (component C) is preferably in the range of 5 parts by weight or more and less than 30 parts by weight with respect to 100 parts by weight of the polypropylene resin (component B) having no hydrophilic polar group.

The Z-average particle diameter of the dispersion particles composed of the polypropylene resin (component B) having no hydrophilic polar group and the modified polyurethane resin (component A) having an anionic functional group containing the tackifier (component C) is preferably 500 nm or less.

An adhesive composition containing the self-emulsifying emulsion according to any one of the above and an adhesive for polyolefin resins.

A modified polyurethane resin having an anionic functional group (Component A), a polypropylene resin having no hydrophilic polar group (Component B) and a tackifier (Component C) are dissolved in a solvent and water, and a basic compound is added. and then distilling off the solvent.

In the self-emulsifying emulsion of the present invention, a modified polyurethane resin (component A) having an anionic functional group encapsulates a polypropylene resin (component B) having no hydrophilic polar group and a tackifier (component C). Since it is uniformly and stably dispersed in water in the form of fine particles, it has good storage stability. In addition, since the B component does not have a hydrophilic polar group, it has a high affinity with polyolefin base materials such as polypropylene and polyethylene. In addition, the A component not only functions to emulsify the B component and the C component, but also imparts adhesion to the surface of an adherend such as an olefin base material, thereby stabilizing the adhesive strength of the B component and the C component. Furthermore, since an emulsifier is not substantially used, a coating film prepared using the emulsion does not have unevenness and is excellent in adhesion to polyolefin resins such as polypropylene and polyethylene and in water resistance.

Embodiments of the present invention will be described below.

<Modified Polyurethane Resin Having Anionic Functional Group (Component A)>
The modified polyurethane resin (component A) having an anionic functional group (hereinafter also simply referred to as "modified polyurethane resin" or "component A") used in the present invention is particularly limited as long as it is a polyurethane resin having an anionic functional group. not. The anionic functional group is not particularly limited as long as it is a functional group exhibiting anionicity, and examples thereof include a carboxylic acid group, a sulfonic acid group, a phosphonic acid group, and a phosphinic acid group. Among them, a carboxylic acid group is preferable from the viewpoint of productivity and ease of control of acid value. Moreover, the modified polyurethane resin is preferably a so-called modified polyester urethane resin having an ester bond in addition to the urethane bond in its structure. Being a modified polyester urethane resin makes it easier to control the molecular weight and acid value, making it easier to include a polypropylene resin (component B) or a tackifier (component C) that does not have a hydrophilic polar group. .

The modified polyurethane resin is not particularly limited, but a modified polyester resin (hydroxyl-terminated prepolymer) is synthesized with a polyol compound and a polycarboxylic acid polyanhydride, and further molecularly extended (chain extended) with a polyisocyanate compound. It is preferable to be Since the modified polyester resin is a reaction product of a polyol compound and a polycarboxylic acid polyanhydride, it can have a carboxyl group at the side chain site of the modified polyester resin, and the concentration and acid value of the anionic functional group, It is advantageous for controlling the molecular weight.

The polyol compound is not particularly limited, but a diol compound is preferred in order to avoid the progress of the gelling reaction. Among them, a diol compound having a rubber skeleton is preferable, and a diol having a butadiene rubber skeleton or a diol having an isoprene rubber skeleton is preferable. Any type of 1,2-butadiene type or 1,3-butadiene type can be used as the butadiene rubber skeleton. Specific examples include poly-1,2-butadiene polyol, poly-1,3-butadiene polyol, polyisoprene polyol, and hydrogenated polyols thereof. Although the number average molecular weight of the polyol compound is not particularly limited, it is preferably 1,000 or more, more preferably 1,200 or more, and even more preferably 1,500 or more. Moreover, less than 5000 is preferable, 4500 or less is more preferable, and 4000 or less is further preferable. If it is less than 1000, the carboxyl group concentration in the modified polyester resin and the modified polyurethane resin to be generated becomes too high, and the compatibility with the polypropylene resin to be encapsulated decreases and the inclusion becomes impossible, or the olefin group of the adherend. Adhesion may decrease due to decreased affinity with the material. On the other hand, if it is 5000 or more, the carboxyl group concentration in the produced resin becomes insufficient, and the self-emulsification function may be lost. Moreover, it is not preferable because it loses versatility as a polyol compound raw material.

The polycarboxylic acid polyanhydride is not particularly limited, but is preferably a tetracarboxylic dianhydride from the viewpoint of availability and reactivity. Specific examples thereof include pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, and ethylene glycol bis trimellitic anhydride. Ethylene glycol bis trimellitic anhydride is preferred because of its affinity with the olefin base material that is the adherend.

The reaction between these polyol compounds and tetracarboxylic dianhydrides is preferably carried out in a toluene or xylene solution at 100° C. or higher under normal pressure, and using an amine as a catalyst, because the reaction proceeds relatively efficiently. Amines are not particularly limited, and triethylamine and trimethylamine can be used. In the present invention, it is effective to add a polyisocyanate compound after synthesizing the modified polyester (hydroxyl-terminated prepolymer) thus obtained to extend the molecule and increase the molecular weight.

The polyisocyanate compound that can be used in the present invention is not particularly limited, and various compounds commonly used for polymerization of polyurethane resins can be used. Among them, diisocyanate compounds are preferable, and aromatic diisocyanate compounds or aliphatic diisocyanate compounds are more preferable. Specifically, although not particularly limited, 4,4'-diphenylmethane diisocyanate or 1,6-hexane diisocyanate is preferable in terms of versatility and reactivity.

Synthesis of the modified polyurethane resin is usually carried out at 40 to 60° C. under normal pressure. As a catalyst, a small amount of a tin compound such as dibutyltin dilaurate may be added as needed. Further, when amines, which are catalysts during the synthesis of the modified polyester resin, are present in the reaction system, the amines also act as catalysts for the reaction between isocyanate groups and hydroxyl groups, so a new catalyst must not necessarily be added. No need.

The acid value of the modified polyurethane resin is preferably 100 eq/ton or more, more preferably 150 eq/ton or more, and even more preferably 200 eq/ton or more. Also, it is preferably 500 eq/ton or less, more preferably 400 eq/ton or less. If it is too small, the emulsifying function may be insufficient and an emulsion may not be formed. If it is too large, the polarity of the resin will be excessively high, and the affinity with the polypropylene resin (component B) that does not have a hydrophilic polar group will deteriorate. , it may not be possible to enclose.

The urethane bond group concentration of the modified polyurethane resin is preferably 500 eq/ton or less, more preferably 400 eq/ton or less, still more preferably 300 eq/ton or less. Since the urethane bond group is formed by the reaction between the hydroxyl group and the isocyanate group of the modified polyester resin, it has a high polarity. Performance may be degraded.

The number average molecular weight of the modified polyurethane resin is preferably 10,000 or more, more preferably 15,000 or more, and even more preferably 20,000 or more. Also, it is preferably 50,000 or less, more preferably 45,000 or less, and even more preferably 40,000 or less. If it is less than 10,000, the adhesion performance may be insufficient and the emulsion forming ability may be lowered. On the other hand, when it exceeds 50,000, the emulsion forming ability may be lowered.

<Polypropylene-based resin having no hydrophilic polar group (component B)>
The polypropylene-based resin (component B) having no hydrophilic polar group (hereinafter also simply referred to as "polypropylene-based resin" or "component B") used in the present invention includes polypropylene and propylene-α-olefin copolymer. It is preferably at least one resin selected from the group consisting of coalescence, and the resin is one in which a hydrophilic polar group for self-emulsification has not been introduced by modification reaction. Here, the propylene-α-olefin copolymer is obtained by copolymerizing propylene as a main component with α-olefin. As the α-olefin, for example, one or several of ethylene, 1-butene, 1-heptene, 1-octene, 4-methyl-1-pentene and the like can be used. Among these, 1-butene is preferred. The ratio of the propylene component to the α-olefin component in the propylene-α-olefin copolymer is not particularly limited, but the propylene component is preferably 50 mol % or more.

The method for producing the propylene-α-olefin copolymer is not particularly limited. It also has excellent properties, which is preferable.

The hydrophilic polar group refers to a functional group necessary for the polypropylene resin to self-emulsify. and ammonium salts and metal bases formed by. Further, having no hydrophilic polar group means that the acid value of the polypropylene resin is preferably 20 eq/ton or less, more preferably 10 eq/ton or less, and 5 eq/ton or less. It is more preferably 1 eq/ton or less, and most preferably 0 eq/ton.

The number average molecular weight of the polypropylene-based resin (component B) having no hydrophilic polar group used in the present invention is preferably from 5,000 to 60,000, more preferably from 7,000 to 55,000. It is more preferably 10,000 to 50,000. If it is less than 5,000, the cohesive force may be weak and the adhesion may be poor. On the other hand, if it exceeds 60,000, the dissolution state deteriorates, and the A component may not be incorporated into the emulsion particles when the emulsion is formed.

The blending amount of the polypropylene-based resin is preferably 20 parts by weight or more, more preferably 25 parts by weight or more, and even more preferably 30 parts by weight or more with respect to 100 parts by weight of the modified polyurethane resin. Also, it is preferably less than 70 parts by weight, more preferably 65 parts by weight or less, and even more preferably 60 parts by weight or less. If the amount is too small, the cohesive force of the entire resin composition may be lowered, and the adhesive strength may be lowered. It may not be formed, or the adhesion of the entire resin composition to the adherend may be excessively reduced, resulting in deterioration of adhesion performance.

<Tackifier (C component)>
The tackifier (component C) used in the present invention is not particularly limited as long as it is a compound capable of imparting tackiness. High compatibility is preferred. If the compatibility is poor, the adhesion performance of the adherend to the olefinic base material may not be exhibited sufficiently. The SP value of a tackifier serves as a rough standard for judging compatibility with polypropylene resins. The SP value of a tackifier that exhibits good compatibility with a polypropylene resin that does not have a hydrophilic polar group is a value according to Hoy's formula, and is 8.3 to 9.0 (J/cm ³ ) ^{1/ 2} is preferred. It is known that the SP value (δ) of a polymer compound such as a tackifier according to Hoy's formula can be obtained as follows.
δ (polymer compound) = ρΣE/M
Here, ρ is the density of the polymer compound, M is the molecular weight of the repeating structural unit of the polymer compound, and E is the molar cohesive energy constant of individual structural units constituting the polymer compound. For the numerical value of E, numerical values published in various documents can be used. References in which numerical values are described include, for example, J. Phys. Paint Technology vol. 42 76-118 (1970).
In addition, as a method to actually check the compatibility, the higher the transparency of the dry coating film prepared by mixing the polypropylene resin (component B) that does not have a hydrophilic polar group and the tackifier (component C), the better. It is judged that compatibility is high. Transparency can be visually confirmed, but can be judged more accurately by using a HAZE meter (preferably 1.0 or less, more preferably 0.5 or less) or the like. Alternatively, the dynamic viscoelastic properties of the dry film prepared above are measured, and if the main dispersion peak of the loss elastic modulus (E″) is not broader than before the tackifier is added, the compatibility is judged to be good. .

The softening point of the tackifier is preferably 60°C or higher, more preferably 70°C or higher, still more preferably 80°C or higher, preferably 160°C or lower, more preferably 150°C or lower, and even more preferably 140°C or lower. The number average molecular weight is preferably 500 or more, more preferably 700 or more, still more preferably 800 or more, preferably 1800 or less, more preferably 1600 or less, and even more preferably 1500 or less. If it is less than 500, the physical properties of the modified polyurethane resin coating film may deteriorate and bleeding may occur on the surface of the coating film, and if it exceeds 1800, the compatibility with the modified polyurethane resin may deteriorate.

The tackifier (component C) used in the present invention is not particularly limited, but is preferably selected from terpene-based resins, rosin-based resins, and petroleum-based resins, and more preferably terpene-based resins. Specific examples of commercially available products include Clearon (registered trademark) series (SP value: 8.36 to 8.55 (J/cm ³ ) ^1/2 ) manufactured by Yasuhara Chemical Co., Ltd., YS resin series (SP value: 8 .73 (J/cm ³ ) ^1/2 ), YS polyester series polyester U, T and S (SP value: 8.69 to 8.98 (J/cm ³ ) ^1/2 )).

The amount of the tackifier (component C) is preferably 5 parts by weight or more and less than 30 parts by weight, more preferably less than 30 parts by weight with respect to 100 parts by weight of the polypropylene resin (component B) having no hydrophilic polar group. It is 10 parts by weight or more and less than 25 parts by weight. If it is less than 5 parts by weight, the effect of the tackifier may not be obtained. A stable emulsion may not be formed, or the cohesive force of the entire emulsion (resin composition) may be excessively reduced, resulting in deterioration of adhesion performance.

<Self-emulsifying emulsion>
The self-emulsifying emulsion of the present invention comprises (1) a modified polyurethane resin having an anionic functional group (component A) dispersed in water in the absence of an emulsifier, and (2) a modified polyurethane resin having an anionic functional group. Dispersion particles composed of (A component) enclose a polypropylene resin (B component) and a tackifier (C component). That is, if the modified polyurethane resin (component A), the polypropylene resin (component B), and the tackifier (component C) are uniformly and stably dispersed in water without containing any emulsifier, they are encapsulated. It can be judged that

Dispersion particles made of modified polyurethane resin (component A) enclose polypropylene resin (component B) and tackifier (component C), and are dispersed uniformly and stably in water in the form of fine particles, resulting in storage stability. Furthermore, it has excellent adhesiveness, adhesiveness, and water resistance to polyolefin resin substrates such as polypropylene and polyethylene.

In the self-emulsifying emulsion of the present invention, the state of inclusion of the modified polyurethane resin (component A), the polypropylene resin (component B) and the tackifier (component C) includes butadiene rubber of the modified polyurethane resin (component A) or Rubber skeleton sites (hydrophobic sites) such as isoprene rubber chains are inside, and sites (hydrophilic sites) having anionic functional groups (such as carboxyl groups) are outside dispersion particles (micellar particles). A polypropylene resin (component B) and a tackifier (component C) are included in the polyurethane resin (component A). Furthermore, it is believed that the hydrophilic site of the modified polyurethane resin (component A) is neutralized with a basic substance. This can also be estimated from the fact that the average particle size of the emulsion particles (dispersion particles) increases according to the blending amounts of the polypropylene resin (component B) and the tackifier (component C).

In the self-emulsifying emulsion of the present invention, since the polypropylene resin (component B) and the tackifier (component C) are encapsulated in dispersion particles made of the modified polyurethane resin (component A), the polypropylene resin (component B Component) and tackifier (C component) do not require special equipment such as an extruder or emulsifier for emulsifying and dispersing, and emulsification can be performed without the presence of an emulsifier. The presence of no emulsifier in the present invention means that the emulsifier is preferably 0.1 parts by weight or less, more preferably 0.01 parts by weight or less, relative to 100 parts by weight of the modified polyurethane resin (component A). Preferably, it is 0 parts by weight. Since there is no emulsifier, the coating film produced using the emulsion is free from unevenness and has excellent adhesion and water resistance to polyolefin resin substrates such as polypropylene and polyethylene.

Although the Z-average particle size of the self-emulsifying emulsion is not particularly limited, it is preferably 500 nm or less. It is more preferably 450 nm or less, still more preferably 400 nm or less. If it exceeds 500 nm, a stable emulsion may not be formed. Although the lower limit is not particularly limited, it is usually 50 nm or more.

An example of the method for preparing the self-emulsifying emulsion of the present invention is shown below, but the content is not limited to the following. That is, first, a modified polyurethane resin (component A) is polymerized in an aromatic solvent, and then a polypropylene resin (component B) and a tackifier (component C) are added in a predetermined ratio in an ether solvent and an alcohol solvent. and neutralize by adding a basic substance, emulsify by gradually adding deionized water, and after cooling, remove the ether solvent, alcohol solvent and aromatic solvent. can be obtained with

This will be explained step by step.

1) Polymerization of Modified Polyurethane Resin (Component A) Having an Anionic Functional Group A diol compound such as polybutadiene diol or polyisoprene diol, tetracarboxylic acid dianhydride of 1/2 molar amount thereof, and an aromatic solvent are charged, Heat to dissolve evenly. Examples of aromatic solvents include, but are not limited to, benzene, toluene, xylene, ethylbenzene, isopropylbenzene, solvent naphtha, and the like, and these can be used singly or in combination of two or more. Among them, toluene is preferred. The amount of the solvent is preferably such that the total amount of the mixture of the diol component and the tetracarboxylic dianhydride is 50 to 70% by weight.
The reaction temperature is maintained at 100-110° C. and amines are added as a reaction catalyst. The amount to be added is preferably about 0.01 to 0.05% by weight based on the solid weight of the produced resin (modified polyester resin). As amines, various tertiary amines such as triethylamine and trimethylamine can be used, but triethylamine is preferred. The reaction is completed in about 3 hours after the addition of the catalytic amines.

Then, it is preferable to cool the reaction temperature to 40 to 50° C. and add an ether solvent to dilute the solid content of the resin to 50% by weight. At the same temperature, an equimolar amount of diisocyanate compound is added to the previously added tetracarboxylic dianhydride, and reacted at the same temperature for about 2 hours. Examples of the ether-based solvent include, but are not limited to, tetrahydrofuran, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and the like, and these may be used alone or in combination of two or more. can. Among them, tetrahydrofuran is preferred.

2) Preparation of emulsion containing polypropylene resin (component B) and tackifier (component C) After completion of the urethane reaction, add an ether solvent to dilute the solid resin content to 30% by weight. do. While stirring at 60 to 70° C., a predetermined amount of polypropylene resin (component B) pellets is added and uniformly dissolved, and then a predetermined amount of tackifier (component C) is added and uniformly dissolved.

A predetermined amount of alcoholic solvent is added at the same temperature, and the mixture is stirred to be uniform. The alcohol-based solvent is not particularly limited, but includes aliphatic alcohols having 1 to 7 carbon atoms, aromatic alcohols, alicyclic alcohols, and the like, and these may be used alone or in combination of two or more. can. Among them, aliphatic alcohols having 3 to 5 carbon atoms are preferred, and isopropyl alcohol is more preferred from the viewpoint of versatility and compatibility with organic solvents. Next, a basic substance is added while maintaining the same temperature. Examples of basic substances include, but are not limited to, morpholine; ammonia; amines such as methylamine, ethylamine, dimethylamine, triethylamine, ethanolamine, and dimethylethanolamine. They can be used in combination. A preferred basic substance is dimethylethanolamine. The amount of the basic substance used is preferably 1 to 5 chemical equivalents, more preferably 1.5 to 3.5 chemical equivalents, relative to the carboxyl group (anionic functional group) of the modified polyurethane resin (component A). is more preferred. The stability of the self-emulsifying emulsion of the present invention can be further maintained by keeping it neutral to alkaline. As a method for adding the basic substance, it may be added as it is, or it may be added after being diluted with water for more uniform mixing. The temperature and dispersion time at which the basic substance is added are not particularly limited, but are preferably 60° C. to 75° C., the same as the dissolution temperature, and the time required for dispersion is 15 minutes to 30 minutes.

Next, a predetermined amount of deionized water is added little by little while stirring at the same temperature, and the entire amount is added over about 1 hour while maintaining a constant rate.

The ratio of the ether solvent, alcohol solvent and aromatic solvent to be used is not particularly limited, but the weight ratio is ether solvent:alcohol solvent:aromatic solvent=100:3 to 50:3 to 50. is preferably 100:5 to 35:5 to 35. If the ratio of the alcohol-based solvent to 100 parts by weight of the ether-based solvent exceeds 50 parts by weight, the modified polyurethane resin (component A) may become less soluble at high temperatures during the manufacturing process, and uniform dispersion may not be possible. . On the other hand, if the proportion of the aromatic solvent exceeds 50 parts by weight, the particles aggregate to form a large amount of agglomerates, and uniform dispersion may not be possible. If the proportion of the alcohol solvent or the aromatic solvent is less than 3 parts by weight, the effect may not be exhibited and uniform dispersion may not be achieved.

The ratio of the total amount of modified polyurethane resin (component A), polypropylene resin (component B), and tackifier (component C), water, and the total organic solvent of ether solvent, alcohol solvent, and aromatic solvent is Although it can be arbitrarily selected, the weight ratio of the total amount of A component, B component and C component: water: total organic solvent = 100: 50 to 800: 11 to 900, preferably 100: 200 ~400:43~233 is more preferred. When the amount of water or total organic solvent is large, component A is more easily dispersed in water, but it is economically disadvantageous and impractical because it takes a long time to concentrate and the volumetric efficiency decreases. If there is little water, it may not be dispersed. If the total amount of the organic solvent is small, the viscosity may increase significantly during heating and dissolution, and uniform dissolution may not be possible, resulting in failure to achieve uniform dispersion.

Although the temperature for heating and dissolving is not particularly limited, 50° C. or higher is preferable. Moreover, if it is 75° C. or lower, it is not higher than the boiling point of the organic solvent to be used, and a pressure vessel is not required for heating and dissolving, which is preferable.

Next, the organic solvent is removed from the resulting dispersion to obtain a self-emulsifying emulsion. The organic solvent can be removed by distillation under reduced pressure. The degree of pressure reduction and the temperature during distillation are not particularly limited, but are preferably about 90 to 95 KPa (absolute pressure) and about 20 to 60°C. At this time, part of the water may also be distilled off. The composition (weight ratio) of the self-emulsifying emulsion after removing the organic solvent and part of the water by distillation under reduced pressure is the total amount of A component, B component and C component: basic substance: water=1:0. 06-0.33:1.5-4 is preferred. The residual amount of the organic solvent after distillation under reduced pressure is preferably 1 part by weight or less, more preferably 0.1 part by weight or less, with respect to 100 parts by weight of the total amount of components A, B and C. 0 parts by weight is particularly preferred. It should be noted that additional amounts of water can be added as needed.

The self-emulsifying emulsion of the present invention may optionally contain a curing agent. Examples include, but are not limited to, water-soluble polyfunctional epoxy resins, water-soluble polyfunctional carbodiimide resins, polyfunctional isocyanate compound aqueous dispersions, and water-soluble silane coupling agents having polyfunctional silyl groups. Among these, water-soluble polyfunctional epoxy resins are preferred. Specific examples of commercially available products manufactured by Nagase Chemtech Co., Ltd., "Denacol (registered trademark) EX-512", "Denacol EX-521", "Denacol EX-614B", "Denacol EX-821", "Denacol EX -920” and the like. These water-soluble epoxy resins can be added in any proportion to the self-emulsifying emulsion of the present invention. preferably.

In addition, the self-emulsifying emulsion of the present invention may contain various additives such as fillers, pigments, colorants, antioxidants, etc. within limits that do not impair the adhesion performance.

The self-emulsifying emulsion obtained by the present invention has excellent adhesion to polyolefin resin substrates, so it can be used as a primer for painting, printing, adhesion, and coating, as well as for paints, inks, coating agents, and adhesives. Useful.

The polyolefin-based resin substrate may be appropriately selected from conventionally known polyolefin resins. For example, although not particularly limited, polyethylene, polypropylene, ethylene-propylene copolymer, and the like can be used. Pigments and various additives may be added to the polyolefin resin base material, if necessary.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. "Parts" in the examples and comparative examples indicate parts by weight. Moreover, the measurement/evaluation method employed in the present invention is as follows.

(1) Measurement of number average molecular weight of modified polyester resin and modified polyurethane resin A measurement sample was obtained by filtering through a polytetrafluoroethylene membrane filter. Using a gel permeation chromatograph (GPC) 150C manufactured by Waters, tetrahydrofuran was used as a carrier solvent, and an RI detector was used at a flow rate of 1 ml/min. As columns, three Shodex KF-802, KF-804 and KF-806 manufactured by Showa Denko KK were connected and the column temperature was set at 30°C. A polystyrene standard substance was used as a molecular weight standard sample.

(2) Acid Value of Modified Polyurethane Resin After dissolving 0.2 g of a sample (80% toluene solution of modified polyurethane resin) in 20 ml of tetrahydrofuran, the acid value was measured with a 0.1N-NaOH ethanol solution using phenolphthalein as an indicator. The measured value was shown in terms of the number of equivalents (eq/ton) in 10 ⁶ g of resin solid content.

(3) Polymer Composition A sample was dissolved in a mixed solvent of chloroform-d/DMSO-d ₆ =1/1, and ¹ H-NMR was obtained using a nuclear magnetic resonance spectrometer (NMR) “Gemini-400-MR” manufactured by Varian. The resin composition ratio was determined by analysis.

(4) Measurement of Emulsion Solid Content Concentration About 1 g of sample emulsion is placed in a 50 ml glass weighing bottle and accurately weighed. Next, the weighing bottle containing the sample is dried in a hot air dryer at 120° C. for 2 hours, placed in a desiccator, left at room temperature for 30 minutes, and cooled. The weighing bottle is taken out from the desiccator, the weight is accurately weighed, and the weight % of the emulsion solid content concentration is calculated from the weight change (the following formula) before and after the hot air drying.
Emulsion solid content concentration (% by weight) = [(Sample weight before hot air drying) - (Sample weight after hot air drying)] / (Sample weight before hot air drying) x 100

(5) Determination of content of modified polyurethane resin, polypropylene resin, and tackifier content The dry sample (resin) obtained by the measurement of the solid content concentration above was dissolved in deuterated chloroform and analyzed with a nuclear magnetic resonance spectrometer (NMR) manufactured by Varian. ) Using “Gemini-400-MR”, the ratio of modified polyurethane resin (component A), polypropylene resin (component B) and tackifier (component C) was determined by ¹ H-NMR analysis.

(6) Measurement of emulsion viscosity Using "Viscometer TV-22" (E-type viscometer) manufactured by Toki Sangyo Co., Ltd., a 0.6 g sample is measured by rotor No. Measured under the conditions of 0.8° (=48′)×R24, range H, number of revolutions 5 rpm, and 25°C.

(7) Measurement of emulsion pH The value at 25°C was measured using "pH meter F-52" manufactured by Horiba. The calibration of the measuring instrument was made by Wako Pure Chemical Industries, Ltd., phthalate pH standard solution (pH: 4.01), neutral phosphate pH standard solution (pH: 6.86), borate pH standard A liquid (pH 9.18) was used, and three-point measurement was performed.

(8) Measurement of Z-average particle size of emulsion Using Malvern's "Zetasizer Nano Nano-ZS Model ZEN3600", a sample prepared to a concentration of 0.05 g / L was measured three times at 25 ° C., and the average value and

(9) Evaluation of Storage Stability of Emulsion The emulsions prepared in Examples and Comparative Examples were stored in a static state in an incubator at 40° C., and changes in appearance of the emulsion over time were observed. The longer the appearance (3 months or longer), the better.

(10) Evaluation of Adhesion and Adhesion to Olefin Base Material <Polyethylene Plate//Polypropylene Film Peeling Test (Adhesion)>
Dynol (registered trademark) 604 (manufactured by Air Products Co., Ltd.) was added as a leveling agent to the emulsions obtained in Examples and Comparative Examples in an amount of 0.5% by weight based on the emulsion. The formulation is applied to a 2 mm thick, 25 mm x 100 mm high-density polyethylene test piece manufactured by Paltec Co., Ltd. using a #16 wire bar, leaving about 1 cm of one end of the test piece as a gripping margin for a chuck of a tensile tester. and dried in a hot air dryer at 100°C for 10 minutes. A 25 mm x 200 mm size 60 µm thick OPP film was pasted on the coated surface immediately after it was removed from the dryer so that the chuck gripping margins were in the same direction, and a load of 120 kg/m ² was applied and the oven was heated to 100°C. and aged for 10 minutes to obtain adherent samples. After leaving the adhesive sample taken out of the oven overnight at room temperature, a peel test was performed using a tensile tester (“RTM-100” manufactured by Orientec). A 180° peel test was performed by holding the end of the polyethylene test piece with one chuck and the end of the OPP film with the other, and pulling it vertically at a pulling speed of 50 mm/min using a 5 kgf load cell. The same test was carried out four times, and the average value of the measured strength was taken as the peel strength. At the same time, the peeled surface was observed to confirm the peeled state.
(criterion)
◎: 3.0 N/cm or more (in a state of complete cohesion and peeling, adhesive resin remains on the entire peeled surface of both the peeled polyethylene and OPP, and the strongest adhesive strength is obtained.)
○: 2.0 N / cm or more and less than 3.0 N / cm (Both the part peeled at the polyethylene interface and the part peeled at the OPP interface are mixed, and a relatively strong adhesive strength can be obtained.)
Δ: 1.0 N/cm or more and less than 2.0 N/cm (Polyethylene interfacial peeling and weak adhesion are obtained.)
x: Less than 1.0 N/cm (Polyethylene interfacial peeling, almost no adhesiveness is obtained.)

<Polyethylene plate cross-cut peeling test (adhesion)>
Dynol (registered trademark) 604 (manufactured by Air Products Co., Ltd.) was added as a leveling agent to the emulsions obtained in Examples and Comparative Examples in an amount of 0.5% by weight based on the emulsion. The formulation was applied to a 2 mm thick, 25 mm×100 mm high-density polyethylene test piece manufactured by Paltec Co., Ltd. using a #8 wire bar, and dried in a hot air dryer at 100° C. for 10 minutes. Using a cross-cut guide with a width of 2 mm, 10×10 squares were cut on the surface of the obtained coating film with a sharp cutter knife, and a cellophane tape manufactured by Nichiban Co., Ltd. was pasted. After confirming that the entire bonded surface was firmly in contact with the adherend surface, the tape was peeled off at once. The number of squares of the coating film remaining on the surface of the adherend (polyethylene test piece) was counted and used as the evaluation result. Thus "100" means the best value and "0" means the worst result. The same sample was evaluated three times, and the average value was adopted.

(11) Evaluation of Water Resistance of Coating Film Dynol (registered trademark) 604 (manufactured by Air Products Co., Ltd.) as a leveling agent was added to the emulsions obtained in Examples and Comparative Examples in an amount of 0.5% by weight based on the emulsion. The coating solution of the formulation was applied to a 25 μm thick OPP film using a #40E wire bar and dried at 120° C. for 30 minutes with a hot air dryer. The resulting coating film was cut into strips of 2.5 cm x 30 cm, stored in a desiccator containing silica gel for 24 hours, and dried to obtain strip-shaped coating films (water resistance test samples). Then, each strip-shaped coating film was taken out, placed in a hermetically sealed metal can, and the coating film weight was precisely weighed. The strip-shaped coating film was taken out from the metal can, immersed in hot water at 40°C for 5 minutes, then taken out, the water adhering to the surface was carefully wiped off with gauze, and it was placed in the hermetic metal can again and accurately weighed. The weight increase rate of the coating film due to water absorption before and after immersion in warm water was calculated and used as an index of water resistance. The evaluation criteria were as follows, depending on the weight increase rate of the coating film.
○: Weight increase rate after immersion in warm water <2.5%
△: Weight increase rate after immersion in warm water 2.5 to 3.5%
×: Weight increase rate after immersion in warm water >3.5%

[Synthesis Example 1]
Modified polyester urethane resin containing an anionic functional group (Component A): Synthesis example of A-1 Hydrogenated poly-1,2 manufactured by Nippon Soda Co., Ltd. was placed in a 1 L four-necked flask equipped with a stirring rod, a thermometer, and a condenser. 240 parts of butanedienediol (GI-3000) and 80 parts of toluene were charged and uniformly dissolved at 100°C. Next, 12.5 parts of TMEG-200 manufactured by Shin Nippon Rika Co., Ltd. was added, and the mixture was stirred until uniform, and 0.03 part of triethylamine was added as a reaction catalyst. After stirring at the same temperature for 3 hours, the reaction solution was cooled to 60°C and diluted with 173 parts of tetrahydrofuran. Further, while stirring at the same temperature, 7.2 parts of 4,4'-diphenylmethane diisocyanate was added, and after 3 hours, the reaction was completed. Dilute with 354 parts of tetrahydrofuran to obtain a 30% by weight solution of modified polyester urethane resin (A-1). The acid value and number average molecular weight of the modified polyester urethane resin (A-1) were as follows.
Acid value: 230eq/ton
Number average molecular weight: 32,000

[Synthesis Example 2]
Modified polyester urethane resin having an anionic polar group (Component A): Synthesis example of A-2 Poly-1,2-butanediene manufactured by Nippon Soda Co., Ltd. was placed in a 1 L four-necked flask equipped with a stirring rod, a thermometer, and a condenser. 100 parts of diol (G-3000), 100 parts of Mitsubishi Chemical poly-1,3-butadiene-polyacrylic block copolymer oligomer diol (Polytail (registered trademark) H) and 100 parts of toluene were charged and dissolved uniformly. , the temperature was kept at 100°C. Next, 13.3 parts of TMEG-200 manufactured by Shin Nippon Rika Co., Ltd. was added, and the mixture was stirred to be uniform, and 0.03 part of triethylamine was added as a reaction catalyst. After stirring at the same temperature for 3 hours, the reaction solution was cooled to 50°C and diluted with 120 parts of tetrahydrofuran. Further, while stirring at the same temperature, 6.6 parts of 4,4'-diphenylmethane diisocyanate was added, and after stirring at the same temperature for 3 hours, the reaction was completed. Dilute with 293 parts of tetrahydrofuran to obtain a 30% by weight solution of modified polyester urethane resin (A-2). The acid value and number average molecular weight of the modified polyester urethane resin (A-2) were as follows.
Acid value: 290eq/ton
Number average molecular weight: 33,000

[Preparation Example 1]
Self-emulsifying emulsion: preparation example of E-1 100 parts of a 30% by weight solution of the modified polyester urethane resin (A-1) was charged into a 1 L four-necked flask equipped with a stirring rod, a thermometer and a condenser, and heated to 60°C. After heating, 15 parts of Elmodu (registered trademark) S-400 (polypropylene) manufactured by Idemitsu Kosan Co., Ltd. as the B component and terpene phenolic resin manufactured by Yasuhara Chemical Co., Ltd. (YS Polyster T130 (SP value: 8.81 (J / cm) ³ ) ^1/2 )) was charged and dissolved in 2.3 parts. After adding 10 parts of isopropyl alcohol, 1.5 parts of dimethylaminoethanol was mixed with 2 mL of deionized water and added dropwise at the same temperature using a dropping funnel. After stirring at the same temperature for about 10 minutes, 150 parts of deionized water was added dropwise over about 1 hour to obtain a dispersion. After completion of the dropwise addition, the organic solvent component and part of the water were distilled off from the dispersion under reduced pressure using a rotary evaporator to obtain emulsion (E-1). The resulting emulsion (E-1) had a solid content concentration of 29.0% by weight, a viscosity at 25° C. of 3.8 mPa·s, a pH of 9.4, and a Z-average particle size of 245 nm. Further, when the emulsion (E-1) was stored in an incubator at 40° C. and its storage stability was evaluated, no change in appearance was observed after 3 months. These results are summarized in Table-1.

[Preparation Example 2]
Self-emulsifying emulsion: preparation example of E-2 In the same manner as the above emulsion (E-1), Elmodu (registered trademark) S-400 manufactured by Idemitsu Kosan Co., Ltd. as the B component and Yasuhara Chemical as the C component Emulsion (E-2) was obtained in the same manner except that the amount of terpene phenol resin (YS Polystar T130) charged was changed to 8 parts and 1 part, respectively. The resulting emulsion (E-2) had a solid content concentration of 31.2% by weight, a viscosity at 25° C. of 5.6 mPa·s, a pH of 9.5, and a Z-average particle size of 194 nm. In Preparation Example 2, the amounts of the polypropylene resin and the tackifier were reduced from those in Preparation Example 1, so it can be seen that the average particle size is smaller than in Example 1. Emulsion E-2 was stored in an incubator at 40° C., and storage stability was evaluated. No change in appearance was observed after 3 months. These results are summarized in Table-1.

[Preparation Example 3]
Self-emulsifying emulsion: preparation example of E-3 100 parts of a 30% by weight solution of the modified polyester urethane resin (A-2) was placed in a 1 L four-necked flask equipped with a stirring rod, a thermometer, and a condenser, and the mixture was heated to 60°C. After warming, 13 parts of Elmodu S-400 manufactured by Idemitsu Kosan Co., Ltd. as the B component and 1.9 parts of the terpene phenol resin YS Polyster T130 manufactured by Yasuhara Chemical Co., Ltd. as the C component were charged and dissolved. After adding 10 parts of isopropyl alcohol, 1.5 parts of dimethylaminoethanol was mixed with 2 mL of deionized water and added dropwise at the same temperature using a dropping funnel. After stirring at the same temperature for about 10 minutes, 150 parts of deionized water was added dropwise over about 1 hour to obtain a dispersion. After completion of the dropwise addition, the organic solvent component and part of the water were distilled off from the dispersion under reduced pressure using a rotary evaporator to obtain emulsion (E-3). The resulting emulsion (E-3) had a solid content concentration of 30.9% by weight, a viscosity at 25° C. of 7.2 mPa·s, a pH of 9.3, and a Z-average particle size of 220 nm. Further, the emulsion (E-3) was stored in an incubator at 40° C. and evaluated for storage stability, and no change in appearance was observed after 3 months. These results are summarized in Table-1.

[Adjustment example 4]
Self-emulsifying emulsion: Preparation example of E-4 In the same manner as the emulsion (E-3), Elmodu (registered trademark) S-400 manufactured by Idemitsu Kosan Co., Ltd. as the B component and Yasuhara Chemical Co., Ltd. as the C component Emulsion (E-4) was obtained in the same manner except that the amount of terpene phenol resin (YS Polystar T130) charged was changed to 13 parts and 2.6 parts, respectively. The resulting emulsion (E-4) had a solid content concentration of 29.9% by weight, a viscosity at 25° C. of 7.0 mPa·s, a pH of 9.4, and a Z-average particle size of 252 nm. Further, the emulsion (E-4) was stored in an incubator at 40° C. and evaluated for storage stability, and no change in appearance was observed after 3 months. These results are summarized in Table-1.

[Preparation Example 5]
Self-emulsifying emulsion: E-5 preparation example 100 parts of a 30% by weight solution of the modified polyester urethane resin (A-2) was charged in a 1 L four-necked flask equipped with a stirring rod, a thermometer, and a condenser, and heated to 60°C. After that, 13 parts of Lycosene PP1602 (polypropylene) manufactured by Clariant Co., Ltd. as B component and hydrogenated terpene resin Clearon (registered trademark) P125 manufactured by Yasuhara Chemical Co., Ltd. as C component (SP value: 8.36 (J / cm ³ )) ^1/2 ) was dissolved. After adding 10 parts of isopropyl alcohol, 1.5 parts of dimethylaminoethanol was mixed with 2 mL of deionized water and added dropwise at the same temperature using a dropping funnel. After stirring at the same temperature for about 10 minutes, 150 parts of deionized water was added dropwise over about 1 hour to obtain a dispersion. After completion of the dropwise addition, the organic solvent component and part of the water were distilled off from the dispersion under reduced pressure using a rotary evaporator to obtain emulsion (E-5). The obtained emulsion (E-5) had a solid content concentration of 30.2% by weight, a viscosity at 25° C. of 6.6 mPa·s, a pH of 8.9, and a Z-average particle size of 229 nm. Further, the emulsion (E-5) was stored in an incubator at 40° C. and evaluated for storage stability, and no change in appearance was observed after 3 months. These results are summarized in Table-1.

Self-emulsifying emulsion: preparation example of E-6 In the same manner as the above emulsion (E-5), Lycosene PP1602 manufactured by Clariant Co., Ltd. as component B and hydrogenated terpene resin Clearon manufactured by Yasuhara Chemical Co., Ltd. as component C ( Emulsion (E-6) was obtained in the same manner except that the charged amount of P125 was changed to 13 parts and 0.7 parts, respectively. The resulting emulsion (E-6) had a solid content concentration of 30.1% by weight, a viscosity at 25° C. of 6.8 mPa·s, a pH of 9.6, and a Z-average particle size of 212 nm. Further, the emulsion (E-6) was stored in an incubator at 40° C. and evaluated for storage stability, and no change in appearance was observed after 3 months. These results are summarized in Table-1.

[Comparative Preparation Example 1]
Self-Emulsifying Emulsion: Comparative Preparation Example of E-7 Emulsion (E-7) was obtained in the same manner as for emulsion (E-1) except that component C was not used. The resulting emulsion (E-7) had a solid content concentration of 30.8% by weight, a viscosity at 25° C. of 4.7 mPa·s, a pH of 9.4, and a Z-average particle size of 216 nm. Further, the emulsion (E-7) was stored in an incubator at 40° C. and evaluated for storage stability, and no change in appearance was observed after 3 months. These results are summarized in Table-1.

[Comparative Preparation Example 2]
Self-Emulsifying Emulsion: Comparative Preparation Example of E-8 Emulsion (E-8) was obtained in the same manner as emulsion (E-1) except that component B was not used. The resulting emulsion (E-8) had a solid content concentration of 28.8% by weight, a viscosity at 25° C. of 3.1 mPa·s, a pH of 9.3, and a Z-average particle size of 173 nm. Further, the emulsion (E-8) was stored in an incubator at 40° C. and evaluated for storage stability, and no change in appearance was observed after 3 months. These results are summarized in Table-1.

[Comparative Preparation Example 3]
Self-emulsifying emulsion: Comparative preparation example of E-9 Emulsion (E-9) was obtained in the same manner as the above emulsion (E-1) except that B and C components were not used. rice field. The resulting emulsion (E-9) had a solid concentration of 29.8% by weight, a viscosity at 25° C. of 4.1 mPa·s, a pH of 9.1, and a Z-average particle size of 169 nm. Further, when the emulsion (E-9) was stored in an incubator at 40° C. and its storage stability was evaluated, no change in appearance was observed after 3 months. These results are summarized in Table-1.

Below, after adding a carboxyl group to the B component by a modification reaction to obtain a polypropylene resin having a hydrophilic polar group, without using the A component, the B component itself forms a self-emulsifying emulsion. A comparative example is shown.

[Comparative Synthesis Example 1]
Comparative Synthesis Example of Acid Addition-Modified Polypropylene Resin (B-1) 300 parts of Elmodu S-901 (polypropylene) manufactured by Idemitsu Kosan Co., Ltd. were placed in a pressurizable 1 L metal reactor equipped with a stirring rod and a thermometer. 25 parts of maleic anhydride and 450 parts of toluene were charged, and after purging with nitrogen, the temperature was raised to 130° C. over 2 hours in a pressurized system. Then, 12 parts of Perbutyl D was added as a reaction catalyst, heated to 140° C., and reacted at the same temperature for 3 hours. After 3 hours, the inside of the reaction system was returned to normal pressure and normal temperature, and the reaction product was taken out and reprecipitated in 1 L of methyl ethyl ketone to remove unreacted maleic acid component. After washing with an additional 1 L of methyl ethyl ketone, the product was cooled and ground into a slurry. The resulting slurry was deliquored using a centrifuge and then dried overnight at 50° C. using a vacuum dryer to obtain an acid addition modified polypropylene resin (B-1) in the form of flakes. The molecular weight and acid value of B-1 thus obtained were as follows.
Number average molecular weight: 35,000
Acid value: 220eq/ton

[Comparative Synthesis Example 2]
Comparative Synthesis Example of Acid Addition-Modified Polypropylene Resin (B-2) In the same manner as in B-1 above, instead of Idemitsu Kosan Co. Polypropylene) was used and maleic anhydride was added in the same process to obtain an acid addition-modified polypropylene resin (B-2). The molecular weight and acid value of B-2 thus obtained were as follows.
Number average molecular weight: 33,000
Acid value: 240eq/ton

[Comparative Preparation Example 4]
Self-emulsifying emulsion: Comparative preparation example of E-10 140 g of deionized water, 50 parts of the above acid addition-modified polypropylene resin (B-1), 38 parts of tetrahydrofuran, 8 parts of isopropyl alcohol and 8 parts of toluene are mixed with a stirring rod and a thermometer. , charged into a 1 L four-necked flask equipped with a condenser, heated to 70° C., and then heated and dissolved at the same temperature for 2 hours. Next, 2.0 parts of dimethylethanolamine was added, and after stirring for 1 hour while maintaining the same temperature, the mixture was gradually cooled to 40°C. Then, the organic solvent component and part of the water were distilled off from the resulting dispersion using a rotary evaporator under reduced pressure to obtain an emulsion (E-10). The resulting emulsion (E-10) had a solid content concentration of 25.5% by weight, a viscosity at 25° C. of 7.2 mPa·s, a pH of 8.6, and a Z-average particle size of 262 nm. Further, the emulsion (E-10) was stored in an incubator at 40° C., and storage stability was evaluated. After 1 week, formation of aggregates was confirmed on the inner wall and bottom of the container. These results are summarized in Table-2.

[Comparative Preparation Example 5]
Emulsifier-combined type emulsion: Comparative preparation example of E-11 In the same manner as the above emulsion (E-10), together with the acid addition modified polypropylene resin (B-1), "Neopelex (registered trademark) G-" manufactured by Kao Corporation An emulsion (E-11) was prepared by blending 5 parts of 65″ and following the same procedure. The resulting emulsion (E-11) had a solid content concentration of 28.5% by weight, a viscosity at 25° C. of 6.3 mPa·s, a pH of 8.5, and a Z-average particle size of 362 nm. Emulsion (E-11) was stored in an incubator at 40° C. and storage stability was evaluated. After 2 months, precipitation of aggregates was observed on the bottom of the container. These results are summarized in Table-2.

[Comparative Preparation Example 6]
Self-emulsifying emulsion: Comparative preparation example of E-12 Using the acid addition modified polypropylene resin (B-2) instead of the acid addition modified polypropylene resin (B-1) in the same manner as the above emulsion (E-10), A slightly turbid yellow homogeneous emulsion (E-12) was obtained in the same manner. The resulting emulsion (E-12) had a solid content concentration of 30.2% by weight, a viscosity at 25° C. of 10.2 mPa·s, a pH of 9.1, and a Z-average particle size of 168 nm. Further, when the emulsion (E-12) was stored in an incubator at 40° C. and its storage stability was evaluated, no change in appearance was observed after 3 months. These results are summarized in Table-2.

Examples 1-6
The above adhesion test and water resistance test were carried out using the emulsions E-1 to E-6 obtained in the above synthesis examples and preparation examples, and the results are summarized in Table-3.

Comparative Examples 1-6
Using the emulsions E-7 to E-12 obtained in the above comparative synthesis examples and comparative preparation examples, the above adhesion test and water resistance test were carried out, and the results are summarized in Table-3.

As is clear from Table 3, when a polypropylene resin is subjected to acid addition modification to form a self-emulsifying emulsion, good adhesion to polyethylene substrates cannot be obtained. On the other hand, by incorporating a tackifier (component C) into an emulsion of polyester urethane (component A), which has a high affinity for olefin base materials, without subjecting the polypropylene resin to acid addition modification, it is effective against polyethylene base materials. Good adhesiveness is exhibited. In addition, the addition of an emulsifier significantly lowers the adhesion to the adherend and the water resistance of the coating film.

Since the self-emulsifying emulsion of the present invention has excellent adhesion to polyolefin resin substrates, it is useful as a primer for painting, printing, adhesion, and coating, as well as for paints, inks, coating agents, and adhesives. be.

Claims (7)

It contains a modified polyurethane resin (component A) having an anionic functional group, a polypropylene resin (component B) having no hydrophilic polar group, and a tackifier (component C), and contains (1) and (2) below. Satisfactory self-emulsifying emulsion.
(1) A modified polyurethane resin (component A) having an anionic functional group is dispersed in water without the presence of an emulsifier. (2) Dispersion particles composed of a modified polyurethane resin (component A) having an anionic functional group. Contains a polypropylene resin (component B) and a tackifier (component C) that do not have hydrophilic polar groups The polypropylene resin (component B) having no hydrophilic polar group is contained in the range of 20 parts by weight or more and less than 70 parts by weight based on 100 parts by weight of the modified polyurethane resin (component A) having an anionic functional group. The self-emulsifying emulsion according to claim 1. Claim 1 or 2, wherein the tackifier (component C) is contained in a range of 5 parts by weight or more and less than 30 parts by weight with respect to 100 parts by weight of a polypropylene resin (component B) having no hydrophilic polar group. The described self-emulsifying emulsion. The Z-average particle diameter of the dispersion particles composed of the polypropylene resin (component B) having no hydrophilic polar group and the modified polyurethane resin (component A) having an anionic functional group containing the tackifier (component C) is 500 nm or less, the self-emulsifying emulsion according to any one of claims 1 to 3. An adhesive composition containing the self-emulsifying emulsion according to any one of claims 1 to 4. An adhesive for polyolefin resins containing the adhesive composition according to claim 5 . A modified polyurethane resin having an anionic functional group (Component A), a polypropylene resin having no hydrophilic polar group (Component B) and a tackifier (Component C) are dissolved in a solvent and water, and a basic compound is added. and then distilling off the solvent.