JP6996077B2 - Adhesive-imparting resin, adhesive / adhesive, hot melt adhesive - Google Patents

Description

The present invention relates to a tackifier resin, a sticky / adhesive containing the tackifier resin, and a hot melt adhesive containing the tackifier resin.

In the present specification, the "adhesive / adhesive" is an adhesive and / or an adhesive, and the "hot melt adhesive" is an adhesive that is applied to a support in a molten state to form an adhesive layer in a cooled and solidified state. Means (see JIS K 6800 above).

The rosin ester, which is a reaction product of rosin and polyol, has been used as a tackifier resin in hot melt adhesives, solvent-based adhesives / adhesives, emulsion-type adhesives / adhesives, etc. (see Patent Documents 1 to 3). ..

These adhesives / adhesives may be used under high temperature conditions, and in that case, those having a high softening point are used as the rosin ester. As such, for example, a reaction product of a so-called fortified rosin and a polyol (enhanced rosin ester) obtained by reacting an α, β unsaturated carboxylic acid such as fumaric acid with rosin is known (Patent Documents 4 and 5). See).

On the other hand, when the conventional reinforced rosin ester is used as a tackifier resin for a hot melt adhesive, the compatibility with the base resin, particularly the ethylene-vinyl acetate copolymer, may be insufficient. Further, the hot melt adhesive containing the rosin ester may have insufficient heating stability such as turbidity or peeling during heating, or may not have sufficient coating workability due to its high melt viscosity.

Special Table 6-501515 Gazette Japanese Unexamined Patent Publication No. 9-25371 Japanese Unexamined Patent Publication No. 2010-77429 Japanese Unexamined Patent Publication No. 60-288476 Japanese Unexamined Patent Publication No. 63-275685

The subject of the present invention is that when used as a tackifier resin for a hot melt adhesive, the compatibility with the base resin is good, the melt viscosity of the hot melt is lowered, and the heating stability thereof is improved. It is an object of the present invention to provide a novel rosin ester type tackifier resin which can be improved.

According to the present inventor, the conventional reinforced rosin ester contains a large amount of the polybasic resin acid shown in the following structure, for example, which serves as a branch point and has a very high molecular weight, so that it is the base of the hot melt adhesive. I thought it would be difficult to dissolve with the resin.

In order to reduce the molecular weight of the fortified rosin ester, the amount of α, β unsaturated carboxylic acid used may be reduced to reduce the degree of fortification, but such a low molecular weight fortified rosin esul significantly increases the melt viscosity of the hot melt agent. It lowers and also deteriorates heating stability.

Therefore, as a result of repeated studies on a raw material rosin that can achieve high molecular weight without using α, β unsaturated carboxylic acid, the present inventor has decided to use a rosin containing a highly reactive dibasic resin acid. It has been found that a tackifier resin having the desired effect can be obtained.

That is, the present invention comprises a tackifier resin containing rosins (a1) containing a diterpene carboxylic acid and a rosin ester (A) containing a polyol (a2) as reaction components, and the tackifier resin and a base resin. Concerning the viscous / adhesive and hot melt adhesive contained.

Since the rosin ester, which is a tackifier resin of the present invention, contains a bibasic diterpene carboxylic acid, it exhibits performance equal to or higher than that of the conventional enhanced rosin ester without being modified with α, β unsaturated carboxylic acid.

Specifically, the tackifier resin of the present invention has good compatibility with a base resin for a hot melt adhesive, particularly an ethylene-vinyl acetate copolymer, and provides a homogeneous and transparent hot melt adhesive. Further, since the hot melt adhesive according to the present invention has a relatively small melt viscosity, it has good coating workability and also has good heating stability, so that turbidity and skinning occur even when heated for a long time. hard. In addition, the hot melt adhesive is also excellent in heat resistance holding power.

The tackifier resin of the present invention is suitable for hot melt adhesive applications, but is also suitable for solvent-type adhesives / adhesives, emulsion-type adhesives / adhesives, and the like.

The tackifier resin (hereinafter, also referred to as a component) of the present invention is a rosin (a1) (hereinafter, also referred to as a component (a1)) containing a dibasic diterpene carboxylic acid represented by the following structural formula, and a polyol (a2). ) Is a reaction component, and is a composition containing a rosin ester (A) (hereinafter, also referred to as a component (A)).

The dibasic diterpene carboxylic acid can be classified into dihydroagatoic acid, olibergic acid, eperenedicarboxylic acid and piniphoric acid according to its stereoisomeric structure. The non-limiting structure of dihydroagatoic acid is shown below.

The bibasic diterpene carboxylic acid has a unique structure in which a primary carboxyl group is attached to an alicyclic skeleton via a flexible alkyl chain. Further, the primary carboxyl group has high reactivity and easily reacts with (a2) described later to easily form a high molecular weight polyester. The non-limiting structure of the polyester is shown below.

Since the component (A) contains a polyester having such a characteristic molecular skeleton, it is presumed that the component (A) exerts an action effect equal to or higher than that of the conventional reinforced rosin ester even if it is not reinforced and modified.

The content of the diterpene carboxylic acid in the component (a1) is not particularly limited, but if the content of the carboxylic acid is too small, the softening point of the component (A) is lowered and the heat-resistant holding power is lowered. There is a tendency. Further, if the content of the carboxylic acid is too large, the molecular weight of the component (A) becomes high, the compatibility and the heating stability deteriorate, and the melt viscosity also becomes relatively high, and the coating workability deteriorates. Tend to do. From the viewpoint of heat retention, compatibility, heat stability and melt viscosity balance, the content of diterpene carboxylic acid is usually less than 20% by weight, preferably about 1 to 15% by weight, more preferably 3 to 13. It should be about% by weight.

Examples of the component (a1) include the following aspects.

(A): Rosin originally containing diterpene carboxylic acid (b): Rosin consisting of a combination of the component (a) and rosin not containing diterpene carboxylic acid (c): Dihydroagatoic acid. A rosin that does not contain basic diterpene carboxylic acid and / or a rosin that is combined with the component (a).

As the component (a), as long as it is a rosin containing a diterpene carboxylic acid, the place of origin and the pine species do not matter. For example, Indonesian rosin and Vietnamese rosin contain a relatively large amount of diterpene carboxylic acid. In particular, rosins (gamrosin, tall oil rosin, wood rosin, etc.) derived from Pinus merkusii from Indonesia and Vietnam contain dihydroagatoic acid exclusively. Further, a hydride or an attenuated rosin of the rosin can also be used.

The component (a) may be purified by various known methods. Specific examples thereof include operations such as distillation, recrystallization and extraction. The distillation conditions are not particularly limited, and usually, the temperature is about 200 to 300 ° C. and the pressure is about 130 to 1300 Pa. For recrystallization, the component (a) is dissolved in a good solvent such as benzene, toluene, xylene, chloroform, lower alcohol, acetone, ethyl acetate, etc., and then the good solvent is distilled off to form a concentrated solution. A poor solvent such as n-hexane, n-heptane, cyclohexane, or isooctane may be added to the solution. For extraction, the component (a) may be an alkaline aqueous solution, an insoluble unkenzide may be extracted with an appropriate solvent, and then the aqueous layer may be neutralized.

As the rosin containing no diterpene carboxylic acid, which is a component of (a), various known rosins can be used without particular limitation. Specifically, for example, natural rosins such as gum rosin, tall oil rosin, and wood rosin, purified rosins obtained by purifying natural rosins, hydrides obtained by hydrogenating natural rosins, and natural rosins are non-uniform. Examples thereof include disproportionate rosin obtained by a chemical reaction.

The diterpene carboxylic acid constituting the component (c) can be prepared, for example, by the method described in JP-A-51-131899.

The component (a1) includes, for example, abietic acid and dehydroabietic acid as resin acids other than the diterpene carboxylic acid dibasic. The content thereof is not particularly limited, but is usually less than 60% by weight and less than 30% by weight, preferably about 20 to 50% by weight and about 5% by weight.

The content of the resin acid in the component (a1) can be quantified by various known means. For example, it can be obtained by using gas chromatography (GC) and dividing the peak area derived from the resin acid for quantification by the peak area of the total resin acid.

The physical characteristics of the component (a1) are not particularly limited, but usually the softening point is usually about 70 to 90 ° C., and the acid value is usually about 130 to 200 mgKOH / g.

As the component (a2), various known polyols can be used. Specifically, for example, diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, dimerdiol and 1,6-hexanediol, and triols such as glycerin, trimethylolethane and trimethylolpropane, etc. Examples thereof include tetraol such as pentaerythritol, and polyols having a valence of 5 or more such as dipentaerythritol, and two or more thereof can be used in combination. Among these, at least one selected from the group consisting of diol, triol and tetraol is preferable in consideration of the compatibility between the component (A) and the base resin and the performance of the pressure-sensitive adhesive / adhesive according to the present invention.

The amount of the component (a2) used is not particularly limited, but the acid value of the component (a1) (JIS K 0070; hereinafter, the same applies hereinafter) is the same as the acid value of the component (a1), considering the adhesive performance such as heat retention. (A2) The ratio (OH / COOH) to the hydroxyl value in the component (JIS K 0070; hereinafter, the same applies to the water acid value) is usually in the range of about 0.5 to 4.

The reaction component of the component (A) may include various known α, β unsaturated carboxylic acids (a3) (hereinafter, also referred to as the component (a3)), if necessary. Specific examples thereof include α and β unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid, and α and β unsaturated dicarboxylic acids such as fumaric acid and (maleic anhydride) maleic acid. Can be used together.

The amount of the component (a3) used is not particularly limited, but in consideration of the compatibility between the tackifier resin of the present invention and the base polymer, etc., it is usually 0.005 with respect to 1 mol of abietic acid in the component (a1). It is in the range of about 3 mol, more preferably about 0.005 to 0.3 mol.

Examples of the component (A) include the following aspects.

(A1): Esterized product (rosin ester) of component (a1) and component (a2)
(A2): Diels-Alder reaction product (enhanced rosin ester) of component (A1) and component (a3)
(A3): An esterified product of the Diels-Alder reaction product of the components (a1) and (a3) and the component (a2) (enhanced rosin ester).
(A4): Simultaneous reaction product of (a1) component, (a2) component and (a3) component (enhanced rosin ester)

The conditions of the esterification reaction are not particularly limited, and for example, the reaction component is placed in the presence or absence of a solvent and in the presence or absence of an esterification catalyst at about 250 to 280 ° C. and about 1 to 8 hours. It suffices to react under the condition of. Examples of the esterification catalyst include acid catalysts such as paratoluenesulfonic acid, hydroxides of alkali metals such as calcium hydroxide, metal oxides such as calcium oxide and magnesium oxide, and two or more thereof. Can be used together. The esterification reaction may be carried out under normal pressure, reduced pressure, pressure and nitrogen purging, or in a combination atmosphere.

The physical properties of the component (A) are not particularly limited, but in consideration of the compatibility between the component (A) and the base resin, the heating stability of the adhesive / adhesive, the suitability for melt viscosity, the balance between heat retention and holding power, etc. in the present invention. The weight average molecular weight is usually about 800 to 4000, the softening point is usually about 70 to 180 ° C., and the acid value is about 1 to 100 mgKOH / g.

The component (A) includes a cross-linking agent, an anti-slip agent, an antiseptic, an anti-rust agent, a pH adjuster, an antifoaming agent (silicone-based antifoaming agent, etc.), a thickener, a filler, an antioxidant, and a water resistant agent. , Additives such as film-forming aids, pigments and dyes may be included.

The component (A) can be used as a tackifier resin without forming an emulsion in the presence of an emulsifier described later.

The adhesive / adhesive of the present invention is a composition containing the tackifier resin of the present invention and the base resin. The composition can be used as, for example, a hot melt adhesive, a solvent type adhesive / adhesive, and an emulsion type adhesive / adhesive, and is particularly suitable as a hot melt adhesive.

As the base resin, various known ones can be used without particular limitation. Specific examples thereof include ethylene-based copolymers, synthetic rubber-based elastomers, acrylic-based copolymers, acrylic-based polymer emulsions, rubber-based latexs, and the like. The appropriate one may be selected accordingly. Ethylene copolymers and / or synthetic rubber elastomers are preferred for hot melt adhesive applications.

Examples of the ethylene-based copolymer include an ethylene-vinyl acetate copolymer and an ethylene-alkyl (meth) acrylate copolymer. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like, and two or more thereof may be used in combination. can.

Examples of the synthetic rubber-based elastomer include styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-hydrogenated butadiene-styrene block copolymer (SEBS) and Examples thereof include styrene-ethylene / propylene-styrene copolymer (SEPS), and two or more of them can be used in combination.

Examples of the acrylic copolymer (excluding the ethylene-alkyl (meth) acrylate copolymer) include glycidyl (meth) acrylic acid, 2-hydroxyethyl (meth) acrylic acid, (meth) acrylic acid, and fumal. Examples thereof include a copolymer of an active hydrogen group-containing (meth) acrylate such as acid, (anhydrous) maleic acid, and itaconic acid and the above-mentioned alkyl (meth) acrylate, and two or more thereof can be used in combination.

Examples of the acrylic copolymer emulsion include those obtained by emulsifying the acrylic copolymer in the presence of an emulsifier. As the emulsifier, for example, a non-reactive emulsifier and / or a reactive emulsifier can be used.

Examples of the non-reactive emulsifier include dialkyl sulfosuccinate ester salt, alkane sulfonate, α-olefin sulfonate, polyoxyethylene alkyl ether sulfosuccinate ester salt, polyoxyethylene styrylphenyl ether sulfosuccinate ester salt, and naphthalene sulfone. Anionic emulsifiers such as acid formalin condensates, polyoxyethylene alkyl ether sulfate ester salts, polyoxyethylene alkyl phenyl ether sulfate ester salts, polyoxyethylene alkyl ethers, polyoxyethylene styrylphenyl ethers, polyoxyethylene sorbitan fatty acid esters, etc. Nonionic emulsifiers are mentioned.

The reactive emulsifier is, for example, a surfactant having a hydrophilic group such as a sulfonic acid group or a carboxyl group and a hydrophobic group such as an alkyl group or a phenyl group and having a carbon-carbon double bond in the molecule. Can be mentioned. Examples of the carbon-carbon double bond include functional groups such as (meth) allyl group, 1-propenyl group, 2-methyl-1-propenyl group, vinyl group, isopropenyl group and (meth) acryloyl group. Be done. Specific examples of the reactive emulsifier include, for example, a polyoxyethylene alkyl ether having at least one functional group in the molecule, a polyoxyethylene phenyl ether having at least one functional group in the molecule, and sulfosuccinic acid thereof. Examples include ester salts and sulfate ester salts. Examples thereof include polyoxyethylene alkylphenyl ether having at least one functional group in the molecule, a sulfosuccinic acid ester salt thereof, a sulfate ester salt thereof, a phosphoric acid ester salt thereof, and an aliphatic or aromatic carboxylate thereof. .. Further, an acid anhydride-based emulsifier for acidic phosphoric acid (meth) acrylic acid ester, an acid anhydride modified product of rosing lysidyl ester acrylate (see JP-A-4-256249), JP-A-63-23725, JP-A-63-240931. The emulsifier described in Japanese Patent Application Laid-Open No. 62-104802 can also be used.

Examples of the rubber-based latex include natural rubber latex, styrene-butadiene copolymer latex, chloroprene latex and the like, and two or more of them can be used in combination.

Examples of the base resin other than those described above include polyurethane resin, liquid polybutadiene, liquid polyisobutylene, polyvinyl acetal, gelatin, mannan, starch and the like, and two or more of them can be used in combination.

The amount of the tackifier resin and the base resin used in the present invention is not particularly limited, but is usually about 2 to 40 parts by weight (solid content equivalent) of the former 100 parts by weight (solid content conversion).

The viscous / adhesive of the present invention may include other tackifier resins, various known organic solvents, waxes, cross-linking agents, and the above-mentioned additives.

Other tackifier resins include, for example, raw material rosins such as gum rosin, wood rosin and tall oil rosin (excluding those corresponding to the component (a1)), refined products thereof, hydrogenated products, polymers and reinforced products thereof. And the like, and a reaction product of the modified rosin with the component (a2) and / or the component (a3). In addition, C9-based petroleum resin, C5-based petroleum resin and C5 / C9-based petroleum resin, petroleum resins such as hydrogenated products thereof, terpene resin and hydrogenated products thereof and the like can be mentioned.

Examples of the organic solvent include acetone, methyl ethyl ketone, toluene, benzene, ethyl acetate, chloroform, dimethylformamide and the like, and two or more kinds can be used in combination.

Examples of the wax include animal-derived waxes such as beeswax, whale wax and cellac wax, plant-derived waxes such as carnauba wax, wood wax, rice bran wax and candelilla wax, petroleum-derived waxes such as paraffin wax and microcrystallin wax, and waxes. Examples include waxes derived from minerals such as montan wax and ozokerite, and two or more kinds can be used in combination.

As the cross-linking agent, for example, by adding a cross-linking agent such as a polyisocyanate compound, a polyamine compound, a melamine resin, a urea resin, or an epoxy resin, the cohesive force and heat resistance can be further improved. Among these cross-linking agents, it is particularly preferable to use a polyisocyanate compound, and specific examples thereof include 1,6-hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, tolylene diisocyanate, 4,4. -Various known substances such as diphenylmethane diisocyanate can be mentioned. Further, in the acrylic adhesive composition of the present invention, a filler, an antioxidant, an ultraviolet absorber and the like can be appropriately used as needed. Further, in the acrylic adhesive composition of the present invention, various known tackifier resins can be used in combination as long as the object of the present invention is not deviated.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples, but it goes without saying that the scope of the present invention is not limited by them.

In each example, the contents of dihydroagatoic acid (DHAA), abietic acid (AA) and dehydroabietic acid (DAA) in the raw material rosin were measured by the following gas chromatograph mass spectrometer. For measurement, 0.005 g of a sample (rosins) was dissolved in 0.5 g of an on-column methylating agent (phenyltrimethylammonium hydroxyside (PTHA) 0.2 molmethanol solution, GL Sciences Co., Ltd.), and 1 μl was gas chromatograph mass. It was injected into the analysis (GC / MS) and measured. Each content was determined from the methyl ester form of the resin acid. The equipment used is a gas chromatograph mass spectrometer (product name "Agient6890", "Agient5973N"; manufactured by Agilent technologies) and a commercially available column (product name "Advance-DS", manufactured by Shinwa Kako Co., Ltd.).

In each example, the weight average molecular weight (Mw: polystyrene-equivalent value) of the rosin ester was determined under the following conditions.
Analyzer: HLC-8220 (manufactured by Tosoh Corporation)
Column: TSKgelSuperHM-L x 3 Eluent: Tetrahydrofuran Injection Sample concentration: 5 mg / mL
Flow rate: 0.6 mL / min
Injection volume: 100 μL
Column temperature: 40 ° C
Detector: RI

In each example, the softening point (Sp (° C.)) of the rosin ester was measured by the ring ball method of JIS K 2531.

1. 1. Synthesis of adhesive resin

Production Example 1
100 parts of Indonesian gumrosin was dissolved in 100 parts of xylene and extracted once with 5 parts of 48% NaOHaq and 33 parts of water at room temperature. Then, the aqueous layer (extract) was neutralized with dilute hydrochloric acid to extract the liberated resin acid with 33 parts of xylene, and then xylene was distilled off at 200 ° C. to contain 90% by weight of dihydroagatoic acid (acid). A value of 290 mgKOH / g) was obtained.

Example 1
In a reaction vessel equipped with a stirrer, cooling tube, thermometer and nitrogen introduction tube, Indonesian gumrosin (dihydroagatoic acid 10% by weight, abietic acid 35% by weight, dehydroabietic acid 5% by weight, acid value 190 mgKOH / g, Softening point 80 ° C., hereinafter also referred to as ID rosin) 50 parts and Chinese gum rosin (dihydroagatoic acid 0% by weight, abietic acid 50% by weight, dehydroabietic acid 5% by weight, acid value 170 mgKOH / g, softening point 75) ° C. (hereinafter, also referred to as CN rosin) 50 parts were charged and melted at 200 ° C. Next, 1 part of fumaric acid was charged into the reaction system, and the reaction was carried out at 200 ° C. for 1 hour. Next, 15 parts of pentaerythritol was charged into the melt at the same temperature, and an esterification reaction was carried out at 280 ° C. for 10 hours under a nitrogen gas stream. Then, it was subjected to the reduced pressure treatment for 3 hours to synthesize a fortified rosin ester. The physical characteristics are shown in Table 1.

Example 2
In the same reaction vessel as in Example 1, 100 parts of ID rosin was charged and melted at 200 ° C. Next, 15 parts of pentaerythritol was charged into the melt at the same temperature, an esterification reaction was carried out at 280 ° C. under a nitrogen gas stream for 10 hours, and then a reduced pressure treatment was carried out for 3 hours to synthesize a rosin ester. The physical characteristics are shown in Table 1.

Example 3
In the same reaction vessel as in Example 1, 70 parts of CN rosin and 30 parts of ID rosin were charged and melted at 200 ° C. Next, 15 parts of pentaerythritol was charged into the melt at the same temperature, an esterification reaction was carried out at 280 ° C. for 10 hours under a nitrogen gas stream, and then a reduced pressure treatment was carried out for 3 hours to synthesize a rosin ester. The physical characteristics are shown in Table 1.

Example 4
In the same reaction vessel as in Example 1, 98 parts of ID rosin and 2 parts of the resin acid composition obtained in Production Example 1 were charged and melted at 200 ° C. Next, 14 parts of pentaerythritol was charged into the melt at the same temperature, an esterification reaction was carried out at 280 ° C. for 12 hours under a nitrogen gas stream, and then a reduced pressure treatment was carried out for 5 hours to synthesize a rosin ester. The physical characteristics are shown in Table 1.

Comparative Example 1
In the same reaction vessel as in Example 1, 100 parts of CN rosin was charged and melted at 200 ° C. under a nitrogen gas stream. Next, 1 part of fumaric acid was charged into the reaction system, and the reaction was carried out at 200 ° C. for 1 hour. Next, 15 parts of pentaerythritol was charged into the melt at the same temperature, and an esterification reaction was carried out at 280 ° C. for 10 hours under a nitrogen gas stream. Then, it was subjected to the reduced pressure treatment for 3 hours to synthesize a fortified rosin ester. The physical characteristics are shown in Table 1.

Comparative Example 2
In the same reaction vessel as in Example 1, 100 parts of CN rosin is melted, 5 parts of fumaric acid is charged, and the reaction is carried out at 200 ° C. for 1 hour. Next, 13 parts of pentaerythritol was charged, the temperature was raised to 280 ° C. under a nitrogen gas stream, and the esterification reaction was carried out at the same temperature for 10 hours. Then, it was subjected to the reduced pressure treatment for 3 hours to synthesize a fortified rosin ester. The physical characteristics are shown in Table 1.

Comparative Example 3
100 parts of CN rosin was melted in the same reaction vessel as in Example 1 and melted at 200 ° C. Next, 15 parts of pentaerythritol was charged into the melt at the same temperature, an esterification reaction was carried out at 280 ° C. under a nitrogen gas stream for 10 hours, and then a reduced pressure treatment was carried out for 3 hours to synthesize a rosin ester. The physical characteristics are shown in Table 1.

表１中、ＤＨＡＡはジヒドロアガト酸を、ＡＡはアビエチン酸、ＤＡＡはデヒドロアビエチン酸を意味する。

In Table 1, DHAA means dihydroagatoic acid, AA means abietic acid, and DAA means dehydroabietic acid.

2. 2. Preparation of hot melt adhesive

The component (A1) of Example 1, a commercially available ethylene-vinyl acetate copolymer (trade name EVA # 220, manufactured by Mitsui-Dupont Polychemical Co., Ltd.), and microcrystalline wax (trade name Hi-Mic-1080, Japan). A hot melt adhesive was prepared by mixing the parts (manufactured by Seikan Co., Ltd.) so that the weight ratio was 4/4/2 and melting them under heating.

<Heating stability test>
Weighing 25 g of the hot melt adhesive and heating it in a smooth air dryer at 180 ° C., the presence or absence of turbidity and skinning was determined according to the following criteria at the 24th, 48th, and 72nd hours, respectively. It was visually confirmed. The results are shown in Table 2.
○: Turbidity, no skinning △: Turbidity, some skinning ×: Turbidity, strong skinning

<Measurement of melt viscosity>
The viscosities of the hot melt adhesive at 150 ° C. and 180 ° C. were measured with a commercially available B-type viscometer (rotor: HM-3, rotation speed: 3 rpm). The results are shown in Table 2.

<Compatibility>
2 g of the component (A1) of Example 1 and EVA # 220 2 g were placed in a test tube, mixed under heating and melted, and then the melt was further heated to 200 ° C. and then allowed to cool. The temperature at which the appearance became turbid (cloud point) was measured. Mixtures were prepared in the same manner for the rosin esters of the other examples and comparative examples, and the cloud point was measured in the same manner. The results are shown in Table 2.

<Heat resistance holding power>
The hot melt adhesive according to Example 1 was applied to an aluminum base material, and the length was 7.5 cm and the width was 2.5.
Cut to cm width. This was crimped to another aluminum adherend and then left at 23 ° C. for 1 day. Next, using a commercially available creep measuring device (product name: holding force tester with constant temperature and humidity chamber, manufactured by Tester Sangyo Co., Ltd.), the time until the loaded article falls under the conditions of a load of 1 kg and a temperature of 60 ° C. Was measured, and the heat-resistant holding power was evaluated according to the following criteria.
◯: 2 hours or more Δ: 1.5 hours or more and less than 2 hours ×: less than 1.5 hours

Claims (4)

A rosin ester (A) containing a rosin (a1) containing a diterpene carboxylic acid represented by the following general formula, a polyol (a2) and an α, β unsaturated carboxylic acid (a3) as a reaction component is contained.
The contents of the diterpene carboxylic acid, abietic acid and dehydroabietic acid in the rosins (a1) are 3 to 13 % by weight, 20% by weight or more and less than 60% by weight, and 5% by weight or less and less than 30% by weight, respectively. A certain adhesive resin.

A sticky / adhesive containing the tackifier resin and the base resin according to claim 1. A hot melt adhesive containing the tackifier resin and the base resin according to claim 1. The hot melt adhesive according to claim 3, wherein the base resin contains an ethylene-vinyl acetate copolymer.