WO2019003737A1

WO2019003737A1 - Emulsion containing copolymerized polyolefin, and adhesive composition

Info

Publication number: WO2019003737A1
Application number: PCT/JP2018/020015
Authority: WO
Inventors: 基喜藤本; 木津本　博俊
Original assignee: 東洋紡株式会社
Priority date: 2017-06-28
Filing date: 2018-05-24
Publication date: 2019-01-03
Also published as: JP7107313B2; TW201905141A; JPWO2019003737A1; TWI758497B

Abstract

[Problem] To provide an emulsion having excellent storage stability and exceptional adhesiveness to a substrate. [Solution] An emulsion containing a copolymerized polyolefin and a tackifier, the emulsion satisfying (1)-(3) below. (1) The copolymerized polyolefin is an ethylene-(meth)acrylic acid ester-maleic anhydride ternary copolymer. (2) The copolymerized polyolefin is dispersed in water. (3) Dispersion particles comprising the copolymerized polyolefin encapsulate the tackifier.

Description

Emulsion and adhesive composition containing copolymerized polyolefin

The present invention relates to an emulsion that exhibits good adhesion performance to olefin resin substrates such as polyethylene and polypropylene.

It has long been studied about techniques for bonding low surface energy substrates such as polyethylene and polypropylene, and it is known that designing of an adhesive having high bonding performance to these materials is not easy. As a method to develop good adhesion to these low surface energy base materials, a technique is proposed in which the surface of the adherend is pretreated beforehand by corona discharge, plasma treatment, etc. to increase the surface energy before bonding. It is done. While these techniques are effective techniques, they also require expensive equipment and increase power consumption.

On the other hand, products using olefin-based materials such as polyethylene and polypropylene tend to increase in recent years widely from household products around us to various industrial applications. In particular, for automotive applications, mounting of molding materials made of polypropylene has been actively promoted from the trend of weight reduction of automobiles. From such a background, in recent years, more effective adhesives than ever before have been developed. In addition, due to problems with working environment, adhesives are also changing from conventional organic solvents to more environmentally friendly water systems.

Tackifiers are used in the above-mentioned adhesives for the purpose of imparting tackiness, improving adhesion, etc. For example, Patent Document 1 describes a water dispersion containing a polyolefin resin and a tackifier. It is done.

Patent No. 4033732

In the case of using a tackifier as the adhesive as described above, it is important to select a tackifier according to the substrate (adherend). However, in the above Patent Document 1, since the method of mixing the tackifier dispersed in water with the emulsifier and the aqueous polyolefin resin dispersion is adopted by the emulsifier, the tackifier which is difficult to disperse in water can not be used, Even when a water-dispersible tackifier is used, the storage stability of the aqueous dispersion may be adversely affected depending on the interaction with the aqueous polyolefin resin dispersion. In particular, since olefin substrates such as polyethylene and polypropylene have low polarity and a very low SP value of around 8.0, in order to improve the adhesion to these substrates, adhesion with a relatively close SP value is desirable. Although it is necessary to use a imparting agent, such tackifiers are difficult to mix with the aqueous polyolefin resin dispersion because they have poor hydrophilicity. Therefore, the polyolefin resin aqueous dispersion which can utilize various tackifiers according to the to-be-adhered body was desired.

The present invention is an emulsion containing a polyolefin resin and a tackifier, which exhibits excellent storage stability regardless of the type of tackifier and exhibits good adhesion performance to an olefin-based resin substrate such as polyethylene and polypropylene. And an adhesive composition containing the emulsion.

In order to achieve the above-mentioned subject, the present inventors earnestly examined and came to propose the following invention.

That is, the present invention is an emulsion containing a copolymerized polyolefin and a tackifier and satisfying the following (1) to (3).
(1) Copolymerized polyolefin is ethylene- (meth) acrylic acid ester-maleic anhydride terpolymer (2) Copolymerized polyolefin is dispersed in water (3) Dispersion particles consisting of copolymerized polyolefin Contains a tackifier

The 50% number average particle diameter of the tackifier-containing copolymerized polyolefin dispersion particles is preferably more than 100 nm.

The tackifier is preferably in the range of 5 parts by mass to 80 parts by mass with respect to 100 parts by mass of the copolymerized polyolefin resin.

The emulsion described in any of the above can be used as an adhesive composition and an adhesive for a polyolefin resin.

The emulsion of the present invention is excellent in storage stability because the copolymerized polyolefin is dispersed uniformly and stably in water in the form of fine particles in a state in which the tackifier is contained. Furthermore, since the emulsion and adhesive composition can be produced regardless of the type of tackifier, the adhesion to a substrate is excellent.

Embodiments of the invention

Hereinafter, embodiments of the present invention will be described.

<Copolymerized polyolefin>
The copolymerized polyolefin used in the present invention is a ternary copolymer containing ethylene, (meth) acrylic acid ester, and maleic anhydride as constituent units. The copolymerized polyolefin may be any of ethylene, a (meth) acrylic ester, a random copolymer of maleic anhydride, a block copolymer and a graft copolymer, but is preferably a random copolymer.

The content of the ethylene component is preferably 50% by mass or more and 95% by mass or less, more preferably 50% by mass based on 100% by mass of the total of the ethylene component, the (meth) acrylic acid ester component and the maleic anhydride component. The content is not less than 95% by mass, more preferably not less than 60% by mass, and particularly preferably not less than 70% by mass and not more than 80% by mass. When the content of the ethylene component is less than 50% by mass, the hydrophobicity of the copolymerized polyolefin is too low, and the adhesion to the olefin substrate may be reduced. If the content of the ethylene component is more than 95% by mass, the crystallinity of the copolymerized polyolefin will be high, and thus there is a possibility that water dispersion will be difficult.

Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and the like It can be mentioned. In addition, "(meth) acrylic acid" refers to "acrylic acid or methacrylic acid." When the total of the ethylene component, the (meth) acrylic acid ester component and the maleic anhydride component is 100% by mass, the content of the (meth) acrylic acid ester component is preferably 5% by mass or more and 49% by mass or less More preferably, they are 10 mass% or more and 40 mass% or less, More preferably, they are 15 mass% or more and 30 mass% or less. The most preferable range is 18% by mass to 29% by mass. When the content of the (meth) acrylic acid ester component is less than 5% by mass, the copolymerized polyolefin has a high melting point and may not be suitable for use as an olefin substrate. When the content of the (meth) acrylic acid ester component is greater than 49% by mass, the crystallinity of the copolymerized polyolefin may be significantly reduced and the adhesion may be reduced.

When the total of the ethylene component, the (meth) acrylic acid ester component and the maleic anhydride component is 100% by mass, the content of the maleic anhydride component is preferably 0.01% by mass to 5% by mass. More preferably, it is 0.1 mass% or more and 4 mass% or less, and still more preferably 1 mass% or more and 3 mass% or less. The most preferable range is 1.5% by mass or more and 2.5% by mass or less. When the content of the maleic anhydride component is less than 0.01% by mass, it may be difficult to disperse the copolymerized polyolefin in water. When the content of the maleic anhydride component is more than 5% by mass, the polarity of the copolymerized polyolefin is increased, and the adhesion to a low polarity substrate such as an olefin may be reduced.

The melting point of the copolymerized polyolefin is preferably 50 ° C. to 150 ° C., more preferably 55 ° C. to 100 ° C., and still more preferably 60 ° C. to 90 ° C. If the melting point of the copolymerized polyolefin is less than 50 ° C., the heat resistance may be inferior when used as an adhesive. If the melting point of the copolymerized polyolefin is greater than 150 ° C., it may not be suitable for use on an olefin substrate.

The MFR (melt flow rate) at 190 ° C. and 2160 g load of the copolymerized polyolefin is preferably 0.1 g to 300 g / 10 min, more preferably 1 g to 100 g / 10 min, still more preferably 3 g to 30 g / 10 min It is. When the MFR is less than 0.1 g / 10 minutes, when used as an adhesive, resin sag or the like may occur. If the MFR is more than 300 g / 10 min, the wettability to the substrate may be poor and the adhesion may be reduced.

The acid value of the copolymerized polyolefin is preferably 0.1 mg KOH / g or more and 56 mg KOH / g or less, more preferably 1 mg KOH / g or more and 45 mg KOH or less, and still more preferably 11 mg KOH / g or more and 34 mg KOH / g or less. The most preferable range is 16 mg KOH / g or more and 28 mg KOH / g or less. If the acid value is less than 0.1 mg KOH / g, it may be difficult to disperse the copolymerized polyolefin in water. When the acid value is more than 56 mg KOH / g, the polarity of the copolymerized polyolefin is increased, and the adhesion to a low polar substrate such as an olefin may be reduced.

<Tackifier>
The tackifier used in the present invention is not particularly limited, and rosin resins, terpene resins, coumarone resins, petroleum resins and the like may be used depending on the substrate. The content of the tackifier is preferably 5 parts by mass to 80 parts by mass with respect to 100 parts by mass of the copolymerized polyolefin. More preferably, it is 10 parts by mass or more and 50 parts by mass or less, and still more preferably 20 parts by mass or more and 40 parts by mass or less. If the content of the tackifier is less than 5 parts by mass, the effect of blending the tackifier may not be obtained. When the content of the tackifier is greater than 80 parts by mass, the tackifier can not be contained in the dispersion particles of the copolymerized polyolefin, which may result in an unstable emulsion.

The softening point of the tackifier is also not particularly limited, but is preferably 60 ° C. or more and 160 ° C. or less, more preferably 70 ° C. or more and 150 ° C. or less, and still more preferably 80 ° C. or more and 145 ° C. or less from the viewpoint of adhesion and heat resistance. 86 degrees C or more and 140 degrees C or less are the most preferable. When the softening point of the tackifier is less than 60 ° C., the heat resistance when used as an adhesive may be insufficient. When the softening point of the tackifier exceeds 160 ° C., the wettability to the substrate is poor, and the adhesiveness may be lowered.

The SP value of the tackifier is also not particularly limited, and an appropriate tackifier may be selected according to the substrate. For example, for polyolefins such as polyethylene and polypropylene, the SP value of the tackifier is preferably 8.4 to 8.9 (J / cm ³ ) ^{1/2 according} to the formula of Hoy. More preferably, it is 8.5 to 8.8 (J / cm ³ ) ^1/2 . It is known that the SP value (δ) of a polymer compound such as a tackifier according to the Hoy formula can be determined as follows.
δ (polymer compound) = Σ E E / M
Here, ρ: density of polymer compound, M: molecular weight of repeating structural unit of polymer compound, E: molar cohesive energy constant of individual structural units constituting the polymer compound. The numerical value of E can use the numerical value published in various literature. Examples of documents in which numerical values are listed include J. Paint Technology vol. 42 76-118 (1970).

<Emulsion>
The emulsion of the present invention contains a copolymerized polyolefin and a tackifier, and (1) the copolymerized polyolefin is an ethylene- (meth) acrylate-maleic anhydride terpolymer, (2) a copolymerized polyolefin Is dispersed in water, and (3) dispersion particles comprising a copolymerized polyolefin contain a tackifier (hereinafter, also referred to as tackifier-containing copolymerized polyolefin dispersion particles).

The emulsion has good storage stability, since the dispersion particles comprising the copolymerized polyolefin contain a tackifier and disperse uniformly and stably in water in the form of fine particles. Furthermore, since the emulsion and adhesive composition can be produced regardless of the type of tackifier, the adhesion to a substrate is excellent.

As the encapsulated state of the copolymerized polyolefin and the tackifier in the emulsion of the present invention, the ethylene chain part (hydrophobic part) of the copolymerized polyolefin is inside, and the carboxyl group part (hydrophilic part) derived from maleic anhydride is outside In the form of dispersion particles (micellar particles), the tackifier is contained inside the copolymerized polyolefin. Furthermore, it is considered that the hydrophilic portion of the copolymerized polyolefin is neutralized by the basic substance. Since this alone can not stably disperse or dissolve in water alone, a tackifier which phase separates and precipitates in water is present in the emulsion of the present invention in a uniformly stable state without phase separation and precipitation. It can also be estimated from In addition, when the blending amount of the tackifier is increased, it can be estimated from the fact that the particle diameter of the dispersion particles is increased in proportion to a certain amount.

The 50% number average particle diameter of the tackifier-containing copolymerized polyolefin dispersion particles in the emulsion is preferably larger than 100 nm. If the particle size is 100 nm or less, the adhesion may be reduced. The cause of the decrease in adhesion is not clear, but when the particle diameter is 100 nm or less, the compatibility between the tackifier and the copolymerized polyolefin is extremely high, and when used as an adhesive, the tackifier gets wet at the substrate interface It is guessed that it does not spread. A more preferable particle diameter is 110 nm or more, and more preferably 120 nm or more. Further, the upper limit of the particle size is preferably 500 nm or less. More preferably, it is 400 nm or less, still more preferably 300 nm or less, and particularly preferably 200 nm or less. If the particle size is larger than 500 nm, the storage stability of the emulsion may be reduced.

It is preferable to use an emulsifying agent when preparing the emulsion of the present invention from the viewpoint of dispersion stability and storage stability. The emulsifier is not particularly limited, and examples thereof include anionic emulsifiers, cationic emulsifiers, nonionic emulsifiers (nonionic emulsifiers), amphoteric emulsifiers, reactive emulsifiers and the like. Among these, nonionic emulsifiers are particularly preferred. The HLB of the nonionic emulsifier is preferably 10 or more. HLB is an index representing the balance between hydrophilicity and lipophilicity of the emulsifier (Hydrophile-Lipothhphile Balance initial letter), and the hydrophilicity increases as the value of HLB becomes larger, which is a method proposed by Griffin. When the HLB of the nonionic emulsifier used is less than 10, when the lipophilicity of the emulsifier is too strong, the effect of dispersion stability of the emulsion may be small, and the dispersion stability may be worse than that of the emulsion containing no emulsifier. . The more preferable HLB of the nonionic emulsifier is 12 or more, and the further preferable HLB is 16 or more. The upper limit of HLB is not particularly limited, but is preferably 19 or less.

The type of non-ionic emulsifier is not particularly limited as long as HLB is 10 or more, but, for example, polyoxyalkylene alkyl ether type such as polyoxyethylene lauryl ether, polyoxy acid such as polyoxyethylene styrenated phenyl ether Alkylene styrenated phenyl ether type, polyoxyalkylene alkyl phenyl ether type such as polyoxyethylene nonyl phenyl ether, polyoxyalkylene alkyl amine type such as polyoxyethylene stearyl amine, polyoxyalkylene amine such as polyoxyethylene polyoxypropylene monoamine Type, polyoxyalkylene alkylamide type such as polyoxyethylene oleylamide, polyoxyalkylene fatty acid ester type such as polyoxyethylene monolaurate, poly Ethylene oxide propylene block polymerization type such as xylethylene polyoxypropylene glycol, polyoxyethylene polyoxypropylene tridecyl ether, ethylene oxide propylene random polymerization type, polyoxyethylene sorbitan fatty acid ester such as polyoxyethylene sorbitan monostearate etc Can be mentioned.

The emulsifier may be used alone or in combination of two or more kinds, and may be used in combination of different kinds such as anionic emulsifier and non-ionic emulsifier or the same kind of nonionic emulsifier. When using a combination of nonionic emulsifiers, it is preferable to use an emulsifier different in HLB.

The amount of the emulsifier added is preferably 1 to 25 parts by mass, more preferably 3 to 15 parts by mass, and still more preferably 5 to 10 parts by mass with respect to 100 parts by mass of the copolymerized polyolefin. It is. If the amount of the emulsifier added is smaller than 1 part by mass, the dispersion stability and storage stability of the emulsion may be lowered, and sedimentation of the copolymerized polyolefin may occur. If the amount of the emulsifier added is greater than 25 parts by mass, the adhesion to the substrate may be reduced due to bleed-out of the emulsifier.

Although an example of the preparation method of the emulsion of this invention is shown below, it is not limited to the following content. That is, first, the copolymerized polyolefin and the tackifier are heated and dissolved in an ether solvent, an alcohol solvent, an aromatic solvent and water at a predetermined ratio, an emulsifier is added thereto, and then a basic substance is added. After adding and cooling, it can be obtained by removing an ether solvent, an alcohol solvent and an aromatic solvent.

This will be described step by step.

First, the copolymerized polyolefin and the tackifier are heated and dissolved in an ether solvent, an alcohol solvent, an aromatic solvent and water at a predetermined ratio.

The ether solvent is not particularly limited, and examples thereof include tetrahydrofuran, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, etc. These may be used alone or in combination of two or more. it can. Among them, tetrahydrofuran is preferred.

The alcohol solvent is not particularly limited, and examples thereof include aliphatic alcohols having 1 to 7 carbon atoms, aromatic alcohols, alicyclic alcohols and the like, and one or more of these may be used alone or in combination. it can. Examples of aliphatic alcohols having 1 to 7 carbon atoms include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, pentanol, hexanol and the like. Examples of aromatic alcohols include benzyl alcohol and the like. Cyclohexane methanol etc. are mentioned as alicyclic alcohol. Among them, aliphatic alcohols having 1 to 7 carbon atoms are preferable, aliphatic alcohols having 3 to 5 carbon atoms are more preferable, and isopropyl alcohol is more preferable.

The aromatic solvent is not particularly limited, and benzene, toluene, xylene, ethylbenzene, isopropylbenzene, solvent naphtha and the like can be mentioned, and these can be used singly or in combination of two or more. Among these, toluene is preferred.

The proportions of the ether solvents, alcohol solvents and aromatic solvents to be used are not particularly limited, but the mass ratio is ether solvents: alcohol solvents: aromatic solvents = 100: 3 to 50: 3 to 50 Preferably from 100: 5 to 35: 5 to 35. When the ratio of the alcohol solvent to 100 parts by mass of the ether solvent exceeds 50 parts by mass, the solubility of the copolymerized polyolefin at a high temperature in the production process may be reduced, and uniform dispersion may not be performed. In addition, when the proportion of the aromatic solvent exceeds 50 parts by mass, the particles and the particles may be aggregated to generate a large number of aggregates, and uniform dispersion may not be performed. If the proportion of the alcohol solvent or the aromatic solvent is less than 3 parts by mass, the effect may not be exhibited, and uniform dispersion may not be possible.

Total amount of copolymerized polyolefin and tackifier, water, and ratio of total organic solvent of ether solvent, alcohol solvent and aromatic solvent in a mixed system before heating and dissolving the copolymerized polyolefin and the tackifier Although it can be selected arbitrarily, it is preferable that the total amount of copolymerized polyolefin resin and tackifier: water: total organic solvent = 100: 50 to 800: 10 to 900 by mass ratio, and 100: More preferably, it is 100 to 400: 50 to 450. When the amount of water or the total organic solvent is large, dispersion of the copolymerized polyolefin in water occurs more easily, but it takes time to concentrate and the volumetric efficiency decreases, which is economically disadvantageous and not practical. When water is scarce, it can not be dispersed in many cases. When the total amount of the organic solvent is small, the viscosity significantly increases at the time of heating and dissolution, uniform dissolution can not be performed, and eventually, uniform dispersion may not be possible.

Although the temperature in particular at the time of heat-melting is not restrict | limited, 50 degreeC or more and 150 degrees C or less are preferable. When the dissolution temperature is 50 ° C. or less, the copolymerized polyolefin resin may not be sufficiently dissolved. In the case of 150 degreeC or more, it may become more than the pressure-resistant lower limit of a container. The dissolution time is also not particularly limited, but usually can be completely dissolved in 1 to 2 hours.

The addition of the emulsifying agent may be either before or after the dissolution of the copolymerized polyolefin and the tackifier. As described above, the emulsifier is not particularly limited, and anionic emulsifiers, cationic emulsifiers, nonionic emulsifiers (nonionic emulsifiers), amphoteric emulsifiers, reactive emulsifiers and the like can be used.

The composition of the basic substance may be either before or after the dissolution of the copolymerized polyolefin. Examples of the basic substance include, but are not limited to, morpholine; ammonia; amines such as methylamine, ethylamine, dimethylamine, triethylamine, ethanolamine, dimethylethanolamine etc., and these may be used alone or in combination of two or more. It can be used in combination. The 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, with respect to the carboxyl group of the copolymerized polyolefin. If the amount is less than 1 equivalent, the carboxyl group of the copolymerized polyolefin may not be sufficiently neutralized. If it is more than 5 equivalents, the basicity is too strong, the balance of the acid-base of the dispersion may be broken, and the viscosity may be extremely high. As a method of adding the basic substance, it may be added as it is, but may be diluted with water for more uniform mixing. The time required for dispersion after addition of the basic substance is not particularly limited, but is preferably 1 to 2 hours.

The organic solvent is then removed from the resulting dispersion to obtain an emulsion. In order to remove the organic solvent, it may be distilled off under reduced pressure. The degree of pressure reduction and temperature at the time of distillation are not particularly limited, but about 90 to 95 KPa (absolute pressure), about 20 to 60 ° C. are preferable. At this time, part of the water is also distilled off. The composition (mass ratio) of the emulsion after distilling off the organic solvent and part of the water by distillation under reduced pressure is copolyolefin: basic substance: water = 1: 0.06 to 0.33: 1.5 to 4 Is preferred. The amount of residual organic solvent after distillation under reduced pressure is preferably 1 part by mass or less, more preferably 0.1 part by mass or less, and 0 part by mass with respect to 100 parts by mass of copolymerized polyolefin. Is particularly preferred. In addition, additional water can be added as needed.

The solid concentration in the emulsion is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more. Too little may not be practical. Moreover, it is preferable that it is 50 mass% or less, More preferably, it is 45 mass% or less, More preferably, it is 40 mass% or less. If it is too large, storage stability may be reduced. The solid content in the emulsion refers to the total amount of copolymerized polyolefin, tackifier, emulsifier and basic substance.

<Adhesive composition>
The adhesive composition of the present invention is obtained by blending a curing agent into the above-mentioned emulsion, if necessary. The curing agent is not particularly limited, and examples thereof include water-soluble polyfunctional epoxy resins, water-soluble polyfunctional carbodiimide resins, water dispersions of polyfunctional isocyanate compounds, water-soluble silane coupling agents having polyfunctional silyl groups, and the like. . The curing agent is preferably blended with a functional group weight (an epoxy group weight, a carbodiimide group weight, an isocyanate group weight or a silyl group weight) of 0.8 to 1.2 times equivalent to the acid value of the copolymerized polyolefin, More preferably, it is 0.9 to 1.1 times equivalent. Among these, water-soluble polyfunctional epoxy resins are preferred. As a specific example of a commercial item, Nagase Chemtech Co., Ltd. product "Denacol (registered trademark) EX-512", "Dena call EX-521", "Dena call EX-614 B", "Dena call EX-821", "Dena call EX" -920 "and the like. These water-soluble epoxy resins can be added at any ratio to the emulsion of the present invention, but it is preferable to be blended so as to have an equivalent epoxy group equivalent to the acid value of the copolymerized polyolefin in the emulsion.

In addition, various additives such as fillers, pigments, colorants and antioxidants may be added to the emulsion of the present invention as long as the effects of the present invention are not reduced. The content of the emulsion in the adhesive composition is preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more. Moreover, 99 mass% or less is preferable, More preferably, it is 95 mass% or less. Within the above range, the excellent effects of the present invention can be exhibited.

The emulsion of the present invention is excellent in adhesion to a polyolefin resin substrate, and thus is useful for application in coating, printing, adhesion, a primer for coating, a paint, an ink, a coating agent, and an adhesive.

The polyolefin resin substrate may be suitably selected from conventionally known polyolefin resins. For example, although not particularly limited, polyethylene, polypropylene, ethylene-propylene copolymer and the like can be used. A pigment and various additives may be blended into the polyolefin resin substrate as required.

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. The term "parts" simply in the examples and comparative examples indicates parts by mass. Moreover, the measurement and evaluation method adopted in the present invention are as follows.

1) Measurement of Acid Value of Copolymerized Polyolefin The acid value (mg KOH / g) in the present invention is the amount of KOH required to neutralize 1 g of copolymerized polyolefin, and the test of JIS K 0070 (1992) It measured according to the method. Specifically, after dissolving 1 g of polyolefin in 100 g of xylene whose temperature is adjusted to 100 ° C., 0.1 mol / L potassium hydroxide ethanol solution [trade name “0.1 mol] using phenolphthalein as an indicator at the same temperature / L ethanolic potassium hydroxide solution, manufactured by Wako Pure Chemical Industries, Ltd.]. At this time, the acid value (mg KOH / g) was calculated by converting the amount of potassium hydroxide required for titration into mg.

2) Measurement of emulsion solid content concentration About 1 g of the emulsion of the sample is taken in a 50 ml glass weighing bottle and precisely weighed. Next, the weighing bottle from which the sample was taken is dried in a hot air dryer at 120 ° C. for 2 hours, the weighing bottle taken out is put in a desiccator, and left standing for 30 minutes at room temperature and cooled. The weighing bottle is taken out from the desiccator, the mass is precisely weighed, and the mass% of the emulsion solid content concentration is calculated from the weight change before and after hot air drying (the following formula).
Emulsion solid content concentration (mass%) = [(sample mass before hot air drying) − (sample mass after hot air drying)] / (sample mass before hot air drying) × 100

3) Determination of tackifier content The dried sample (resin) obtained by the measurement of the solid content concentration described above is dissolved in heavy chloroform, and a nuclear magnetic resonance analyzer (NMR) "Gemini-400-MR" manufactured by Varian is used. The ratio of copolymerized polyolefin to tackifier was determined by ¹ H-NMR analysis.

4) Measurement of emulsion viscosity Using “Viscometer TV-22” (E-type viscometer) manufactured by Toki Sangyo Co., Ltd., 0.6 g of the sample was subjected to rotor no. It measured on the conditions of 0.8 degree (= 48 ') x R24, the range H, rotation speed 5rpm, and 25 degreeC.

5) Measurement of emulsion pH The value at 25 ° C. was measured using “pH meter F-52” manufactured by Horiba, Ltd. For calibration of the measuring instrument, phthalate pH standard solution (pH: 4.01), neutral phosphate pH standard solution (pH: 6.86), borate pH standard, manufactured by Wako Pure Chemical Industries, Ltd. The solution (pH 9.18) was used to carry out three-point measurement.

6) Measurement of 50% Number Average Particle Size of Emulsion (Tackifier-Incorporated Copolymerized Polyolefin Dispersion Particles) Sample prepared to a concentration of 0.05 g / L using "Zetasizer Nano Nano-ZS Model ZEN 3600" manufactured by Malvern Was measured at 25.degree. C. three times and taken as the average value.

7) Evaluation of storage stability of the emulsion The emulsions prepared in Examples and Comparative Examples were stored in a stationary state in incubators at 5 ° C., 25 ° C. and 40 ° C., and the time-lapse appearance change of the emulsion was observed. Observations were made one week later, one month later, three months later, six months later and 12 months later, and were scored as follows. 5 points: no change in appearance after 12 months; 4 points: no change in appearance after 6 months (from then on with resin condensation and sedimentation); 3 points: no appearance change after 3 months from then on (from resin condensation and precipitation) 2): no change in appearance after 1 month (from then on with resin condensation and sedimentation) 1 point: no change in appearance after 1 week (from then on resin condensation and precipitation) 0 points after 1 week There is aggregation and sedimentation of resin.

8) Evaluation of Adhesiveness to LDPE Substrate Into the emulsions obtained in Examples and Comparative Examples, 0.5% by mass of Dinol (registered trademark) 604 (manufactured by Air Products Co., Ltd.) was blended as a leveling agent with respect to the emulsion. Apply the formulation to a 0.1 mm thick low density polyethylene (LDPE) film (Mipolone film, manufactured by Mitsuwa Co., Ltd.) using a # 16E wire bar to a dry thickness of 6 μm, 80 It was made to dry for 3 minutes with a hot-air dryer at ° C. Take out from the drier, place the same LDPE film on the coating, and hold it for 30 seconds at 80 ° C and holding pressure of 0.3MPa with a heat seal tester (manufactured by Tester Sangyo Co., Ltd., TP-701-B heat seal tester) The sample for LDPE adhesive strength measurement was shape | molded. After leaving the sample for adhesive strength measurement overnight at room temperature, cut it so that the width becomes 25 mm, and use Tensilon (RTG-1310, A & D Co., Ltd.) to pull up and down at a pulling speed of 50 mm / min. The 180 ° peel adhesion strength was measured by pulling. The same test was carried out five times, and the average value of the measured strength was taken as LDPE adhesion strength.

9) Evaluation of HDPE base material adhesiveness 0.5% by mass of DYNOL (registered trademark) 604 (manufactured by Air Products Co., Ltd.) was blended as a leveling agent to the emulsions obtained in Examples and Comparative Examples. The composition was coated on a high density polyethylene (HDPE) test piece (2.0 × 25 × 100 mm, manufactured by Nippon Test Panel Co., Ltd.) using a # 16E wire bar to a dry thickness of 6 μm. It was made to dry for 3 minutes with a hot-air dryer at 80 ° C. Take out from the drier, bond the same HDPE test piece to the coated surface immediately after so that the bonded part is 25 mm × 15 mm, apply a load of 120 kg / m ² and age for 5 minutes in an oven at 80 ° C, HDPE bonding A sample for strength measurement was obtained. After leaving the sample for adhesive strength measurement at room temperature overnight, measure tensile shear adhesive strength by pulling up and down at a tension rate of 50 mm / min using Tensilon (RTG-1310, A & D Co., Ltd.) did. The same test was carried out five times, and the average value of the measured strength was taken as the HDPE adhesive strength.

The compositions of the copolymerized polyolefin and tackifier used in the following Examples and Comparative Examples are shown in Tables 1 and 2.

Example 1
188 g of deionized water, copolymerized polyolefin manufactured by Japan Polyethylene Corporation (“Lexpearl® ET 230X”; ethylene- (meth) acrylate-maleic anhydride terpolymer (mass ratio: 87.0-12) .0-1.0), MFR: 8.0 g / 10 min, melting point: 88 ° C., acid value: 11 mg KOH / g), 50 g, Yashara Chemical Co., Ltd. tackifier ("YS Polystar (registered trademark) T130"; terpene A phenol resin, a softening point: 130 g), 7.5 g of tetrahydrofuran, 70 g of tetrahydrofuran, 5 g of isopropyl alcohol and 5 g of toluene were placed in an autoclave, heated to 120 ° C., and dissolved by heating at the same temperature for 2 hours. Next, 5.0 g of an emulsifier (“DKS (registered trademark) NL-180”; polyoxyethylene lauryl ether, HLB: 16.1) manufactured by Dai-ichi Kogyo Co., Ltd. was added, and the mixture was further heated and dissolved for 1 hour. Thereafter, 2.5 g of dimethylethanolamine was added, dispersed for 1 hour, and cooled to 40 ° C. (pre-emulsion). Thereafter, the organic solvent / water was distilled off at a pressure reduction degree of 91 kPa (absolute pressure) to obtain a pure white homogeneous emulsion (1). The solid content concentration of this obtained emulsion (1) was 30.4% by mass, the viscosity at 25 ° C. was 12.3 mPa · s, the pH was 8.7, and the 50% number average particle diameter was 140 nm. Further, it was confirmed that the content of the tackifier by NMR was 15 phr (15 parts by mass of the tackifier with respect to 100 parts by mass of the copolymerized polyolefin) as the preparation composition ratio. The emulsion (1) was stored in an incubator at 5 ° C., 25 ° C. and 40 ° C., and storage stability was evaluated. As a result, no change in appearance was observed after 12 months. Moreover, when the LDPE base-material adhesiveness and HDPE base-material adhesiveness were evaluated using the emulsion (1) according to said procedure, they were 3.9 N / cm and 2.5 Mpa, respectively.

Examples 2 to 12
Emulsions (2) to (12) were obtained in the same manner as in Example 1 above, according to the combinations in Table 3. Physical properties and adhesion of the emulsion were measured by the above-mentioned method. The composition and physical properties are shown in Table 3.

Hereinafter, Comparative Example 1 is an example in which an attempt was made to prepare an emulsion using an ethylene- (meth) acrylic acid ester copolymer, and a uniform stable emulsion was not obtained. Comparative Example 2 is an example of producing an emulsion using an acid-modified polyolefin. Comparative Example 3 is an example in which the emulsion particles of the copolymerized polyolefin resin do not contain a tackifier. The comparative example 4 is an example of the emulsion which contains a tackifier by adding a tackifier emulsion with respect to the emulsion which does not contain the above-mentioned tackifier, and is not included in copolymerized polyolefin particle | grains. Comparative Example 5 is an example where an attempt was made to emulsify the tackifier alone with an emulsifier, and a homogeneous stable emulsion was not obtained.

Comparative Example 1
Instead of ethylene- (meth) acrylic acid ester-maleic anhydride terpolymer, copolymerized polyolefin resin ("Lexpearl A4250"; ethylene- (meth) acrylic acid ester copolymer (mass) manufactured by Nippon Polyethylene Co., Ltd. Ratio: 75.0-25.0), MFR: 5.0 g / 10 min, melting point: 92 ° C., acid value: 0 mg KOH / g) An emulsion was prepared in the same manner as in Example 1 except that 50 g was used. An attempt was made to produce (13), but a large amount of coarse particles were generated during cooling, and a uniform dispersion was not obtained.

In order to use instead of copolymerized polyolefin as a comparative example, acid-modified polyolefin (A) was produced with the following method. Propylene-ethylene copolymer (propylene: ethylene = 93: 7 molar ratio, melting point 75 ° C, melt viscosity at 180 ° C: 1500 mPa · s) produced using a metallocene catalyst in a 3 L SUS autoclave reaction vessel 90 g of maleic anhydride, 15 g of dicumyl peroxide, and 1100 g of toluene were added and sealed. After replacing the inside of the autoclave with nitrogen, it was heated and reacted for 5 hours at an in-can temperature of 140 ° C. The reaction solution was cooled to 110 ° C. and poured into a 10 L SUS container containing 3500 g of methyl ethyl ketone (MEK) to precipitate a resin, followed by solid-liquid separation to obtain a resin. The resin was further added to 1000 g of MEK, and the solid-liquid separation washing was repeated three times, and then the resin was dried to obtain an acid-modified polyolefin (A). The content of maleic anhydride in the acid-modified polyolefin (A) obtained was 2.3% by mass, and the weight average molecular weight was 34000.

Comparative example 2
An emulsion (14) was prepared in the same manner as in Example 1 except that 50 g of the acid-modified polyolefin (A) was used instead of the ethylene- (meth) acrylate-maleic anhydride terpolymer. Made. Physical properties and adhesion of the emulsion were measured by the above-mentioned method. The composition and physical properties are shown in Table 4.

Comparative example 3
An emulsion (15) was produced in the same manner as in Example 1 except that the emulsion was produced only from copolymerized polyolefin without using YS polystar T130. Physical properties and adhesion of the emulsion were measured by the above-mentioned method. The composition and physical properties are shown in Table 4.

Comparative example 4
Tackifier made by Harima Chemicals, Inc. ("Hariester SK-385 NS"; rosin type emulsion, solid content: 50 to 166 g (solid content: 50.1 g) of the emulsion (15) (solid content: 30.2 wt%) After adding 15 g (solid content: 7.5 g) of mass%, softening point: 85 ° C., add 11 g of deionized water to adjust the concentration of solid content, and stir the emulsion (16) at room temperature for 1 hour Obtained. Physical properties and adhesion of the emulsion were measured by the above-mentioned method. The composition and physical properties are shown in Table 4.

Comparative Example 5 (Emulsifier Dispersion of Tackifier)
188 g of deionized water, 50 g of tackifier (“YS Polystar T130”; terpene phenol resin, softening point: 130 ° C.) manufactured by Yasuhara Chemical Co., Ltd., 70 g of tetrahydrofuran, 5 g of isopropyl alcohol and 5 g of toluene are placed in an autoclave and heated to 120 ° C. After heating, it was dissolved by heating at the same temperature for 2 hours. Next, 5.0 g of an emulsifier (“DKS NL-180”; polyoxyethylene lauryl ether, HLB: 16.1) manufactured by Dai-ichi Kogyo Co., Ltd. was added, and the mixture was heated and dissolved for 1 hour and then cooled to 40 ° C. . Thereafter, the organic solvent / water was distilled off at a degree of pressure reduction of 91 kPa (absolute pressure), but a tackifier was precipitated during the distillation, and a uniform emulsion was not obtained.

Comparative example 6
The above emulsion (15) and the pre-emulsion before distilling off the organic solvent / water prepared in the above Comparative Example 5 are mixed so as to be copolymerized polyolefin: tackifier = 100: 15 (mass ratio), An emulsion containing an organic solvent was prepared, but the resin immediately precipitated.

The tackifiers used in Examples and Comparative Examples are as follows.
YS Polystar (registered trademark) T130: Terpene phenol resin, softening point: 130 ° C, manufactured by Yashara Chemical Co., Ltd. Alcon (registered trademark) P-90: Aliphatic saturated hydrocarbon resin, softening point 90 ° C, manufactured by Arakawa Chemical Industries, Ltd. Knit Resin (registered trademark) coumarone: coumarone resin, softening point 120 ° C., manufactured by NIPCO CHEMICAL CO., LTD. Hallystar SK-385NS: rosin emulsion, softening point 85 ° C., manufactured by Harima Chemicals, Inc.

Since Examples 1 to 12 satisfy claim 1, they exhibit high adhesion to both LDPE and HDPE, and are also excellent in storage stability. In Comparative Example 1, no ethylene- (meth) acrylate-maleic anhydride terpolymer was used, so a uniform dispersion could not be obtained. The acid-modified propylene-ethylene copolymer is used in Comparative Example 2, and although the adhesion to HDPE is developed, the adhesion to LDPE is poor. In Comparative Example 3, since no tackifier is contained, the adhesion to LDPE and HDPE is poor. Although the tackifier is contained in Comparative Example 4, the storage stability is poor because it is not contained in the copolymerized polyolefin dispersion particles. In Comparative Example 5, an attempt was made to emulsify the tackifier used in the examples, but a uniform dispersion was not obtained. In Comparative Example 6, the emulsion of the copolymerized polyolefin and the emulsion of the tackifier were merely mixed, and the tackifier was not contained in the copolymerized polyolefin dispersion particles, so that the resin was precipitated and an emulsion was not obtained. .

Claims

An emulsion containing a copolymerized polyolefin and a tackifier and satisfying the following (1) to (3).
(1) Copolymerized polyolefin is ethylene- (meth) acrylic acid ester-maleic anhydride terpolymer (2) Copolymerized polyolefin is dispersed in water (3) Dispersion particles consisting of copolymerized polyolefin Contains a tackifier
The emulsion according to claim 1, wherein the 50% number average particle diameter of the tackifier-containing copolymerized polyolefin dispersion particles exceeds 100 nm.
The emulsion according to claim 1 or 2, wherein the tackifier is in the range of 5 parts by mass to 80 parts by mass with respect to 100 parts by mass of the copolymerized polyolefin resin.
An adhesive composition comprising the emulsion according to any one of claims 1 to 3.
The adhesive composition according to claim 4, which is an adhesive for a polyolefin resin.
A method for producing an emulsion, which comprises dissolving a copolymerized polyolefin and a tackifier in a solvent and water, adding a basic substance, and then removing the solvent.