KR20220114103A - Hot melt adhesive for containers with straw - Google Patents

Abstract

Disclosed is a hot melt adhesive comprising: (A) a thermoplastic block copolymer based on a vinylaromatic hydrocarbon and a conjugated diene compound, wherein (A) the thermoplastic block copolymer comprises (A1) component: a styrenic containing diblock copolymer Contains block copolymers. Hot melt adhesives have excellent adhesion to substrates such as paper and polyolefins, excellent adhesion at low temperatures, are suitable for adhering wrapping paper containing straw to containers made of substrates, and furthermore, excellent adhesion to water resistance do. The hot melt adhesive can preferably be used as a hot melt adhesive for containers with straws.

Description

HOT MELT ADHESIVE FOR CONTAINERS WITH STRAW

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Japanese Patent Application No. filed on July 25, 2014. Claiming the benefits under the Paris Convention of 2014-151891, the entirety of which is incorporated herein by reference.

The present invention relates to hot melt adhesives for containers with straws. More particularly, the present invention relates to a hot melt adhesive for attaching a plastic film for packaging straws to containers filled with beverages or the like (eg containers made of paper, metal or plastic).

A container with a straw means a container to which a wrapping paper (a straw-containing wrapping paper or package) is attached, which is obtainable by enclosing a straw for inhalation in a plastic packaging (or packing) bag. The container is mainly filled with beverage. Containers with straws are roughly classified based on the raw material from which the containers are made. A container made of paper is called a "paper package (paper package, beverage box or carton)", and a container made of metal is called a "metal can or (metal) can" (more specifically, a can made of aluminum is aluminum cans, and cans made of steel are called steel cans, etc.), and containers made of plastics such as polypropylene and polyethylene terephthalate, etc. are called plastic cups (or plastic cups).

Patent Document 1 discloses a (metal) can having a straw, and Patent Document 2 discloses a paper package (beverage box or carton) having a straw. Both documents disclose that the wrapper containing (or having) the straw is attached to the container with a hot melt adhesive.

The hot melt adhesive disclosed in Patent Document 1 is a styrene-butadiene-styrene block copolymer (SBS), a styrene-isoprene-styrene block copolymer (SIS), a styrene-ethylene/butylene-styrene block copolymer (SEBS), or a styrene- It is an ethylene/propylene-styrene block copolymer (SEPS)-based hot melt adhesive (refer to [Claim 1] and [Example] of Patent Document 1, etc.).

The hot melt adhesive disclosed in Patent Document 1 is a styrenic hot melt adhesive, and is preferably used for attaching a wrapping paper containing a straw to a metal container. However, the adhesive does not have sufficient adhesion to the paper container and is insufficient to adhere the straws packaged in the paper container.

Patent Document 2 discloses that a packaged straw is fixed to a container with a hot melt adhesive (see Patent Document 2, et al.).

However, in Patent Document 1, the composition of the hot melt adhesive used is not disclosed at all.

Hot melt adhesives for containers with straws have excellent adhesion to plastic films such as polyolefin films for packaging (or packing) straws, and are used to make containers such as paper-based materials, plastic-based materials, etc. It is necessary to have excellent adhesion to the substrate (or base material). Furthermore, considering that the manufactured container is refrigerated, the hot melt adhesive needs to have excellent adhesion at a low temperature (about 5° C.). Also, considering that water droplets (or dew) can condense on the container and containers with straws can be immersed in summer, hot melt adhesives require excellent water-resistant adhesion.

A hot melt adhesive for a container with a straw needs to have various properties suitable for a Beverage container (or beverage container). However, a hot melt adhesive that fully meets the needs of consumers has not yet been found.

Citation List

patent literature

[Patent Document 1]: JP 05-162752 A

[Patent Document 2]: JP 09-278066 A

It is an object of the present invention to have excellent adhesion to substrates (or base materials) such as paper and polyolefins, excellent adhesion at low temperatures (about 5° C.), and wrapping paper (or straws containing straws) for containers made of substrates. -Containing wrapping paper), it is to provide a hot-melt adhesive excellent in water-resistance adhesion in consideration of the fact that a container having a straw is also handled in summer.

The present inventors have studied thoroughly and surprisingly found that a hot melt adhesive comprising a diblock type styrenic block copolymer can solve the above-mentioned problems, and thus completed the present invention.

In one aspect, the present invention provides a hot melt adhesive for a container having a straw, comprising: (A) a thermoplastic block copolymer based on a vinylaromatic hydrocarbon and a conjugated diene compound, wherein (A) the thermoplastic block copolymer comprises: (A1) Component: A styrenic block copolymer containing a diblock copolymer is included.

In one embodiment, the present invention provides a hot melt adhesive wherein component (A1) comprises a styrenic block copolymer having a styrene content of 20-50 wt % and a diblock copolymer content of 20-80 wt %.

In another embodiment, the present invention provides a hot melt adhesive wherein (A) the thermoplastic block copolymer further comprises component (A2): a triblock styrenic block copolymer.

In a preferred embodiment, the present invention provides a hot melt adhesive wherein the hot melt adhesive further comprises (B) a tackifier resin, (C) a softener, and (D) a wax.

In a further embodiment, the present invention provides (C) a hot melt adhesive wherein the emollient comprises a naphthenic oil and/or a paraffinic oil.

Further, in another embodiment, the present invention provides a hot melt adhesive, wherein (D) the wax comprises a Fisher-Tropsch wax.

Further, in a preferred embodiment, the present invention provides a hot melt adhesive wherein the hot melt adhesive comprises component (A1) in an amount of 3-30 parts by weight per 100 parts by weight of the sum of components (A)-(D).

The present invention may provide a wrapper which preferably contains a straw and contains the straw adhered to the container using the hot melt adhesive, or a container having the straw secured to the container using the hot melt adhesive. .

The hot melt adhesive for containers with straw(s) according to the present invention comprises: (A) a thermoplastic block copolymer based on a vinylaromatic hydrocarbon and a conjugated diene compound, wherein (A) the thermoplastic block copolymer is (A1) Ingredients: Includes styrenic block copolymers containing diblock copolymers.

Therefore, the hot melt adhesive has excellent adhesion to substrates such as paper and polyolefin, excellent adhesion at low temperatures (about 5° C.), and is suitable for producing containers having straws.

When component (A1) comprises a styrenic block copolymer having a styrene content of 20-50 wt% and a diblock copolymer content of 20-80 wt%, if the diblock copolymer is contained in a larger amount, the adhesive adhesion is further improved, and the adhesion between the substrate and the adhesive is further improved, and as a result, it is difficult to create a gap between the substrate and the adhesive. Therefore, since it becomes difficult for water to enter into the gap between the packaging paper and the container containing the straw, the hot melt adhesive can have improved water-resistant adhesion.

(A) When the thermoplastic block copolymer further comprises component (A2): a triblock styrenic block copolymer, the hot melt adhesive has improved cohesive strength (or cohesiveness), and the hot melt adhesive has an excellent balance between tack and cohesive strength has Therefore, when the wrapper containing the straw is peeled off from the container, it becomes difficult for the hot melt adhesive to undergo cohesive failure, so that the interface failure may appear more easily, and the straw The containing wrapper can be removed from the container cleaner.

When the hot melt adhesive further comprises (B) a tackifier resin, (C) an emollient and (D) a wax, the adhesive will have a better balance between tack and cohesion, and wrappers containing straw are more easily It can be adhered to the substrate, the coating ability to the substrate can be improved, the adhesion at low temperature can be improved, the coagulation rate after coating can be faster, and the initial cohesive force can be increased more. The wrapper containing the straw can adhere to the container more quickly, and it is more difficult to peel the wrapper containing the straw from the container immediately after attachment.

1 schematically shows a perspective view of a container (a paper package or carton) having a straw;
Fig. 2 schematically shows a front view of a container with a straw (cup made of plastic).

The hot melt adhesive according to the present invention comprises (A) a vinylaromatic hydrocarbon and a conjugated diene compound-based thermoplastic block copolymer (hereinafter referred to as “(A) thermoplastic block copolymer”).

In the present invention, (A) the thermoplastic block copolymer is a block copolymer of a vinylaromatic hydrocarbon and a conjugated diene compound, and a block generally based on a vinylaromatic hydrocarbon (hereinafter referred to as a "vinyl aromatic hydrocarbon block") and It means a resin composition comprising a block copolymer having a block based on a conjugated diene compound (hereinafter referred to as "conjugated diene compound block").

"Vinylaromatic hydrocarbon" means an aromatic hydrocarbon compound having a vinyl group, specific examples of which are styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene , vinylnaphthalene, vinylanthracene, and the like. Styrene is particularly preferred. These vinyl aromatic hydrocarbons may be used alone or in combination.

"Conjugated diene compound" means a diolefin compound having at least one pair of conjugated double bonds. Specific examples of "conjugated diene compounds" include 1,3-butadiene, 2-methyl-1,3-butadiene (or isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene and 1, Contains 3-hexadiene. Among these conjugated diene compounds, 1,3-butadiene and 2-methyl-1,3-butadiene are particularly preferred. These conjugated diene compounds may be used alone or in combination.

The thermoplastic block copolymer (A) according to the present invention may be a non-hydrogenated block copolymer or a hydrogenated block copolymer.

Specific examples of "non-hydrogenated block copolymer" of "(A) thermoplastic block copolymer" contain a block copolymer in which a block based on a conjugated diene compound is not hydrogenated. Specific examples of "hydrogenated block copolymer" of "(A) thermoplastic block copolymer" contain a block copolymer in which a block based on a conjugated diene compound is fully or partially hydrogenated.

The ratio at which the "hydrogenated block copolymer" of the "thermoplastic block copolymer (A)" is hydrogenated can be given by the "hydrogenation ratio". The "hydrogenation ratio" of "thermoplastic block copolymer (A)" is the ratio of double bonds converted to saturated hydrocarbon bonds by hydrogenation, based on all aliphatic double bonds contained in the block based on the conjugated diene compound. indicates The "hydrogenation ratio" can be measured by an infrared spectrophotometer, nuclear magnetic resonance spectroscopy, or the like.

Specific examples of "non-hydrogenated thermoplastic block copolymer" of "(A) thermoplastic block copolymer" contain a styrene-isoprene block copolymer and a styrene-butadiene block copolymer. Specific examples of "hydrogenated block copolymer" of "(A) thermoplastic block copolymer" contain a hydrogenated styrene-isoprene block copolymer and a hydrogenated styrene-butadiene block copolymer.

In the hot melt adhesive according to the present invention, (A) the thermoplastic block copolymer comprises a styrenic block copolymer comprising component (A1): a diblock copolymer (hereinafter referred to as “diblock”).

In one embodiment of the present invention, the styrenic block copolymer (A1) preferably has a styrene content of 20-50 wt%, a diblock content of 20-80 wt%, 100- at 25°C in a 25 wt% toluene solution. It has a viscosity of 3500 mPa.s (or a viscosity of 100-3500 mPa.s at a temperature of 25° C. for a 25 wt % toluene solution).

In this specification, "styrene content" means the ratio of the styrene blocks contained in the styrenic block copolymer. (A1) preferably has a styrene content of 20-50 wt %, more preferably 30-50 wt %.

When the styrene content of the hot melt adhesive according to the present invention is within the above range, at room temperature and low temperature (about 5° C.), the hot melt adhesive has improved cohesive strength and better adhesion to paper, plastic and metal.

In the present invention, "diblock" means a block copolymer comprising two blocks, generally "vinyl-based aromatic block copolymer", preferably "styrene block", and "conjugated diene compound block" or hydrogen It means a block copolymer each containing an addition "conjugated diene compound block", and is represented by the following general formula (1).

S-E: (1)

In the formula (1), "S" represents a vinyl-based aromatic block, preferably a styrene block, and "E" represents a conjugated diene compound block or a hydrogenated "conjugated diene compound block". The conjugated diene compound is preferably butadiene or isoprene.

Accordingly, "diblock content" means the ratio of "diblock copolymer" contained in "styrenic block copolymer". The "diblock content" of component (A1) is preferably 20-80 wt%, more preferably 50-80 wt%.

When the "diblock content" of component (A1) is in the above range, the hot melt adhesive according to the present invention also has excellent water resistance while maintaining adhesion to paper, plastic and metal at standard or low temperatures (about 5° C.) have adhesive strength.

In the present invention, “viscosity at 25° C. in 25 wt % toluene solution” means the viscosity measured at 25° C. of a solution having a concentration of 25 wt % in toluene as a solvent. The viscosity can be measured using various viscometers, for example by a Brookfield BM-type viscometer (spindle No. 2).

Component (A1) preferably has a “viscosity at 25° C. in 25 wt % solution of toluene” of 100-3500 mPa.s, more preferably 100-1000 mPa.s, particularly preferably 100-500 mPa.s has

When component (A1) has a “viscosity at 25° C. in 25 wt % toluene solution” in the above range, the hot melt adhesive according to the present invention has excellent coating ability at low temperatures, can be uniformly applied to a substrate, and then It has better adhesion at low temperatures (about 5° C.).

In the present invention, a commercially available block copolymer can be used as component (A1). Examples of component (A1) contain Asaprene T432 (trade name), Asaprene T438 (trade name) and Asaprene T439 (trade name) manufactured by Asahi Kasei Chemicals Corporation, and Quintac 3270 (trade name) manufactured by Zeon Corporation.

Furthermore, component (A1) may contain a triblock copolymer or the like in addition to the diblock copolymer.

In the present invention, (A) thermoplastic block copolymer preferably further comprises (A2) triblock styrenic block copolymer in addition to component (A1).

The diblock content of the triblock styrenic block copolymer is 0 wt%. That is, the triblock styrenic block copolymer (A2) can be clearly distinguished from the component (A1).

(A2) The styrene content of the triblock styrenic block copolymer is preferably 25-50 wt%, particularly preferably 35-50 wt%. When the styrene content of the component (A2) is within the above range, the hot melt adhesive has improved cohesive strength and may have more improved adhesive strength.

(A2) Examples of the triblock styrenic block copolymer contain a styrene-butadiene-styrene copolymer (hereinafter referred to as "SBS"), a styrene-isoprene-styrene copolymer (hereinafter referred to as "SIS") do.

Further, (A2) the triblock styrenic block copolymer may be hydrogenated. The meaning of the hydrogenated block copolymer has already been mentioned. Examples of the hydrogenated block copolymer include a hydrogenated styrene-isoprene-styrene copolymer (hereinafter referred to as "SEPS") and a hydrogenated styrene-butadiene-styrene copolymer (hereinafter referred to as "SEBS") .

As the triblock styrenic block copolymer (A2), a commercially available product can be used. Examples thereof include TR2000 (trade name), TR2003 (trade name) and TR2250 (trade name) manufactured by JSR Corporation; TUFPRENE 125 (trade name), TUFPRENE A and Asaprene T420 (trade name) manufactured by Asahi Kasei Chemicals Corporation; and Vector 4411A™ and Vector 4211A™ by Dexco Corporation.

When the hot melt adhesive according to the present invention comprises component (A2), the adhesive has more improved cohesive force, and has a better balance between tackiness and cohesive force. Therefore, when the wrapping paper containing the straw is peeled off from the container, the hot melt adhesive is hardly cohesive failure, and thus interfacial failure appears easily, and the wrapping paper containing the straw can be peeled off from the container cleaner.

The present invention also provides a hot melt adhesive for a container having a straw, comprising: (A) a thermoplastic block copolymer based on a vinylaromatic hydrocarbon and a conjugated diene compound, wherein (A) the thermoplastic block copolymer is a diblock Contains styrenic block copolymers.

(A) As the thermoplastic block copolymer comprises a diblock styrenic block copolymer, the adhesive has excellent adhesion to a paper substrate and a polyolefin substrate, excellent adhesion at a low temperature (about 5° C.), and a container having a straw suitable for manufacturing

The hot melt adhesive according to the present invention preferably comprises (B) a tackifier resin, (C) a softener and (D) a wax.

The (B) tackifier resin is not particularly limited as long as the (B) tackifier resin is mainly used in the hot melt adhesive, and the desired hot melt adhesive can be obtained. When the hot melt adhesive comprises (B) a tackifier resin, the adhesive has an excellent balance between cohesive force and tackiness. Thus, wrapping paper containing straw can be more easily attached to substrates such as paper and plastics via a hot melt adhesive.

Examples of the tackifier resin (B) include natural rosin, modified rosin, hydrogenated rosin, glycerol ester of natural rosin, glycerol ester of modified rosin, pentaerythritol ester of natural rosin, pentaerythritol ester of modified rosin, hydrogenated Pentaerythritol esters of rosin, copolymers of natural terpenes, terpolymers of natural terpenes, hydrogenated derivatives of copolymers of hydrogenated terpenes, polyterpene resins, hydrogenated derivatives of phenolic modified terpene resins, aliphatic petroleum hydrocarbon resins, aliphatic hydrogenated derivatives of petroleum hydrocarbon resins, aromatic petroleum hydrocarbon resins, hydrogenated derivatives of aromatic petroleum hydrocarbon resins, cyclic aliphatic petroleum hydrocarbon resins, and hydrogenated derivatives of cyclic aliphatic petroleum hydrocarbon resins.

These tackifier resins may be used alone or in combination. Further, as the tackifier resin, a liquid type tackifier resin can be used as long as it has a colorless to pale yellow tone, is mainly fragrance-free, and has satisfactory thermal stability. Considering these characteristics collectively, the tackifier resin is preferably a hydrogenated derivative of the resin. Also, a non-hydrogenated tackifier resin may be used together.

As the tackifier resin (B), a commercially available product can be used. Examples of such commercial products are Tonex, Ltd. ECR179EX (trade name) manufactured by ; Maruzen Petrochemical Co., Ltd. Maruka Clear H (trade name) manufactured by ; Arakawa Chemical Industries, Ltd. Alcon M100 (trade name) manufactured by ; Idemitsu Kosan Co., Ltd. I-Marv S100 (trade name) manufactured by YASUHARA CHEMICAL CO., LTD. Clearon K100 (trade name), Clearon K4090 and Clearon K4100 (trade name) manufactured by Tonex, Ltd. ECR231C (trade name) and ECR179EX (trade name) manufactured by Regalite C6100L (trade name) and Regalite C8010 (trade name) manufactured by Eastman Chemical Company; and FTR 2140 (trade name) manufactured by Mitsui Chemicals, Inc. Examples of the non-hydrogenated resin include Quinton DX395 (trade name) and Quinton DX390N (trade name) manufactured by Zeon Corporation. These commercially available tackifier resins may be used alone or in combination.

The softening agent (C) is compounded for the purpose of reducing the melt viscosity of the hot melt adhesive, imparting flexibility to the hot melt adhesive, and improving the wettability of the hot melt adhesive to adherends. There is no particular limitation as long as the softening agent (C) is compatible with the block copolymer and the desired hot melt adhesive can be obtained according to the present invention. When the hot melt adhesive according to the present invention contains a softening agent (C), the coating ability (or applicability) of the hot melt adhesive to a substrate such as paper and plastic can be improved, and thus at a low temperature (especially about 5° C.) ), the adhesion can be improved.

emollient (C) Examples of the include paraffin oil, naphthenic oil, aromatic oil, and the like. Component (C) When contains at least one selected from paraffin oil and naphthenic oil, compatibility between component (A) and component (B) is further improved, and each component may be difficult to separate. When each component is not separated and can be more homogeneously mixed with each other, the hot melt adhesive can have more improved adhesive strength.

As the softener (C), a commercially available product can be used. An example of this is Kukdong Oil Chemical Co., Ltd. White Oil Broom 350 (trade name) manufactured by Idemitsu Kosan Co., Ltd. Diana Fresia S32 (trade name), Diana Process Oil PW-90 (trade name) and DN Oil KP-68 (trade name) manufactured by BP Chemicals Ltd. Enerper M1930 (trade name) manufactured by ; Kaydol (trade name) manufactured by Crompton Corporation; Primol 352 (trade name) manufactured by Esso Corp; Idemitsu Kosan Co., Ltd. Process Oil NS100 (trade name) manufactured by KN4010 (trade name) manufactured by PetroChina Company; and SUNPURE N90 (trade name) manufactured by Japan Sun Oil Company, Ltd. These softening agents (C) may be used alone or in combination.

In this specification, wax (D) represents an organic substance that is solid at standard temperature and becomes liquid upon heating, and is mainly regarded as "wax". There is no particular limitation on the wax as long as the hot melt adhesive according to the present invention can be obtained and has wax-like properties. Waxes generally have a weight average molecular weight of less than 10,000.

When the hot melt adhesive according to the present invention includes the wax (D), it may have a faster coagulation rate after coating and may have more improved initial cohesion. Accordingly, the wrapper containing the straw can be quickly attached to the container, and it becomes more difficult to more easily peel the wrapper containing the straw from the container immediately after attachment. The wax (D) is mainly used for hot melt adhesives, and can be modified with a polar functional group or the like as long as the desired hot melt adhesive can be obtained.

Examples of the wax specifically include synthetic waxes such as Fischer-Tropsch wax and polyolefin wax (polyethylene wax and polypropylene, etc.); petroleum waxes such as paraffin wax and microcrystalline wax; and natural waxes such as caster wax and the like.

In the present specification, the wax (D) preferably includes a Fischer-Tropsch wax. Fischer-Tropsch wax means a wax synthesized by the Fischer-Tropsch process, and is mainly referred to as "Fischer-Tropsch wax" (which includes acid-modified waxes). In Fischer-Tropsch wax, the molecules of the component are separated from the wax having a relatively broad carbon number distribution, so that the Fischer-Tropsch wax has a narrower carbon number distribution. When the wax (D) comprises a Fischer-Tropsch wax, the hot melt adhesive can have a more improved balance between the initial cohesive force and the rate of solidification after coating.

Representative examples of Fischer-Tropsch waxes include Sasol Wax, Ltd. Sasol H1 (trade name) commercially available from Sasol H8 (trade name), Sasol H105 (trade name) and Sasol C80 (trade name) is contained.

An example of a commercial product of paraffin wax is Nippon Seiro Co., Ltd Paraffin wax-150 produced by The wax (D) may be used alone or in combination.

The hot melt adhesive according to the present invention preferably comprises (E) a stabilizer (hereinafter referred to as "component (E)") in addition to components (A)-(D).

"Stabilizer" is formulated to improve the stability of the hot melt adhesive by preventing the reduction of molecular weight of the hot melt adhesive due to heat, gelation, coloring, odor, etc. As long as there are no special restrictions. Examples of the "stabilizer" include antioxidants and ultraviolet absorbers.

"Ultraviolet absorber" is used to improve the light resistance of a hot melt adhesive. "Antioxidant" is used to prevent oxidative decomposition of hot melt adhesives. Antioxidants and ultraviolet absorbers are mainly used in paper products (or paper products), and there are no particular restrictions on them as long as the desired paper products mentioned below are obtainable.

Examples of antioxidants include phenolic antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. Examples of the ultraviolet absorber include a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber. In addition, a lactone-based stabilizer may be added. These additives may be used alone or in combination. As the stabilizer, the following commercially available products can be used.

Examples thereof include Sumitomo Chemical Co. Ltd. SUMILIZER GM (trade name), SUMILIZER TPD (trade name) and SUMILIZER TPS (trade name) manufactured by BASF Japan, Ltd. IRGANOX 1010 (trade name), IRGANOX HP2225FF (trade name), IRGAFOS 168 (trade name), IRGANOX 1520 (trade name) and TINUVIN P (trade name) manufactured by and JF77 (trade name) manufactured by Johoku Chemical Co., Ltd; Tominox TT (trade name) manufactured by API Corporation; and AO-412S (trade name) manufactured by ADEKA Corporation. These stabilizers may be used alone or in combination.

The hot melt adhesive according to the present invention may further comprise a fine particle filler. There is no particular limitation as long as a fine particle filler mainly used can be used, and the desired hot melt adhesive according to the present invention can be obtained. Examples of the "fine particle filler" include mica, calcium carbonate, kaolin, talc, titanium oxide, diatomaceous earth, urea-based resin, styrene beads, calcined clay, starch, and the like. These particles are preferably spherical, and there are no particular restrictions on the size (in the case of spherical, diameter).

The hot melt adhesive according to the present invention is prepared by blending the components (A), (B), (C) and (D) using a generally known method for preparing a hot melt adhesive, optionally with a stabilizer ( It can be prepared by blending E) and, if necessary, blending various additives. For example, a hot melt adhesive can be prepared by mixing, heating and melting pre-measured amounts of the above-mentioned ingredients. The compounding order of each component and the heating method are not limited as long as the desired hot melt adhesive can be obtained.

In one embodiment of the present invention, the content of each component is preferably as follows.

In the hot melt adhesive according to the present invention, component (A) is preferably compounded in an amount of 10-40 parts by weight, more preferably 10- It is formulated in an amount of 30 parts by weight. Component (A1) is preferably compounded in an amount of 3-30 parts by weight, more preferably 3-25 parts by weight, based on 100 parts by weight of the total of components (A)-(D). The hot melt adhesive according to the present invention has more excellent balance of adhesive force to substrates such as paper, plastic and metal, when the adhesive contains the above amount of component (A1).

Component (B) is preferably compounded in an amount of 30-70 parts by weight, more preferably 40-60 parts by weight, based on 100 parts by weight of the total of components (A)-(D).

Component (C) is preferably formulated in an amount of 10-50 parts by weight, more preferably 20-40 parts by weight, based on 100 parts by weight of the total of components (A)-(D), and most It is preferably blended in an amount of 20-30 parts by weight.

Component (D) is preferably formulated in an amount of 1-40 parts by weight, more preferably in an amount of 5-25 parts by weight, based on 100 parts by weight of the total of components (A)-(D), and most It is preferably blended in an amount of 5-20 parts by weight.

In the hot melt adhesive according to the present invention, when component (E) is added, component (E) is preferably present in an amount of 0.1-1 parts by weight, based on 100 parts by weight of the total sum of components (A)-(D). added, more preferably in an amount of 0.1-0.5 parts by weight.

In a further preferred embodiment of the present invention, the hot melt adhesive has a viscosity at 160° C. of preferably 6,000 mPa.s or less, more preferably 5,000 mPa.s or less, particularly preferably 1,000 to 2,000 mPa.s (or melt viscosity).

When the viscosity at 160° C. is in the above range, the hot melt adhesive can be applied more easily and homogeneously, and the adhesion between the wrapping paper (or straw-containing wrapping paper) containing straw and the container can be further improved. Herein, the viscosity (or melt viscosity) at 160° C. is measured by a Brookfield viscometer (rotor No. 27) means a value measured by .

The softening point of the hot melt adhesive according to the present invention is preferably 70 to 130°C, more preferably 80 to 120°C, particularly preferably 80 to 110°C. When the softening point is in the above range, the hot melt adhesive can have a more improved balance between initial cohesive force and solidification rate. The softening point can be measured according to the ring and ball method.

The hot melt adhesive according to the present invention may have a variety of forms and is predominantly block-like at standard temperature. A block-like hot melt adhesive may be obtainable by cooling and solidifying a product prepared by the above-mentioned manufacturing method.

The hot melt adhesive according to the present invention can be used to coat the deposit. In coating, hot melt adhesives are also environmentally desirable as there is no need to add solvents to the hot melt adhesives.

The hot melt adhesive may be applied using a generally well known coating method of hot melt adhesive. The coating method is roughly classified into a contact coating method and a non-contact coating method. "Contact coating" method means a coating method in which the discharge is in contact with the member or film when coating with a hot melt adhesive, whereas the "non-contact coating" method refers to a coating method in which the discharge is in contact with the member or film when coating with a hot melt adhesive. It means a coating method that does not come into contact with Examples of the contact coating method include a slot coater coating method, a roll coater coating method, and the like, and examples of the non-contact coating method include spiral coating capable of coating in a spiral shape, coating in a wave shape. Omega coating or control seam coating method that can be applied, slot spray coating or curtain spray coating method that can be applied in flat form, point coating method that can be applied in dot form, and bead coatings that allow for line shaping, and the like.

Since the hot melt adhesive according to the invention can be used for producing containers with straws, the adhesive can be applied particularly preferably by point coating, which can be coated in the form of dots.

The hot melt adhesive can be applied to a wrapper or container containing straws at a temperature of 120 to 180° C. by point coating, and the wrapper containing straw is preferably via a hot melt adhesive to obtain a container having straws. It can be attached to the container.

1 shows a schematic perspective view of a paper package (or paper package) according to an embodiment of a container with a straw of the present invention. As shown in FIG. 1 , a straw insertion hole 3 is formed in the upper surface 2 of the container 1 having a straw. The wrapping paper 6 containing the straws is fixed to the side of the container 1 with the straws with a hot melt adhesive (not shown). The wrapping paper 6 containing the straw encloses the straw 5 with a film such as a polyolefin film.

2 shows a schematic front view of a plastic cup (or plastic cup) according to another embodiment of a container with a straw of the present invention; As shown in FIG. 2 , for a container 1 having a straw, a wrapping paper 6 (including a straw 5 ) containing the straw is transferred to the container (plastic substrate) through a hot melt adhesive (not shown). is attached to the side of Examples of the plastic substrate include polypropylene and polyethylene and the like.

Containers with straws are not limited to the embodiments shown in FIGS. 1 and 2 . For example, the container may be a metal can (such as an aluminum can or a steel can), and the straws may be attached directly to the container without a wrapper containing such straws.

Example

The present invention will be described in order to explain the present invention in a more detailed and specific manner by way of examples. This is illustrative of the invention and should not be considered limiting. In the examples, the solvent-free portion is based on parts by weight and % by weight.

The ingredients for formulating the hot melt adhesive are presented below.

(A) Thermoplastic block copolymer

(A1) diblock-containing styrenic block copolymer

(A1-1) SBS (Asaprene T432 (trade name) manufactured by Asahi Kasei Chemicals Corporation, styrene content: 30 wt%, diblock content: 25 wt%)

(A1-2) SBS (Asaprene T438 (trade name) manufactured by Asahi Kasei Chemicals Corporation, styrene content: 35 wt%, diblock content: 70 wt%)

(A1-3) SBS (Asaprene T439 (trade name) manufactured by Asahi Kasei Chemicals Corporation, styrene content: 45 wt%, diblock content: 62 wt%)

(A1-4) SIS (Qintac 3270 (trade name) manufactured by Zeon Corporation, styrene content: 24 wt%, diblock content: 67 wt%)

(A1-5) SEBS (Kraton G1726 (trade name) manufactured by Kraton Performance Polymers, Inc., styrene content: 30 wt%, diblock content: 70 wt%)

(A2) triblock styrenic block copolymer

(A2-1) SBS (TUFPRENE 125 (trade name) manufactured by Asahi Kasei Chemicals Corporation, styrene content: 40 wt%)

(A2-2) SBS (TUFPRENE A (trade name) manufactured by Asahi Kasei Chemicals Corporation, styrene content: 40 wt%)

(A2-3) SBS (TR 2250 (trade name) manufactured by JSR Corporation, styrene content: 52 wt%)

(B) Tackifier resin

(B-1) Hydrogenation type tackifier resin (Alcon M100 (trade name) manufactured by Arakawa Chemical Industries, Ltd.)

(B-2) Hydrogenated type tackifier resin (I-Marv S100 (trade name) manufactured by Idemitsu Kosan Co., Ltd.)

(B-3) Rosin Ester Type Tackifier Resin (SYLVALITE RE105L (trade name) manufactured by Arizona Chemical Company, LLC)

(C) emollient

(C-1) Paraffin oil (Daphne Oil KP-68 (trade name) manufactured by Idemitsu Kosan Co.)

(C-2) Paraffin oil (Diana Process Oil S32 (trade name) manufactured by Idemitsu Kosan Co.)

(C-3) Naphthenic oil (SUNPURE N90 (trade name) manufactured by Japan Sun Oil Company, Ltd.)

(D) wax

(D-1) Fischer-Tropsch wax (Sasol H1 (trade name) manufactured by Sasol Wax, Ltd.)

(D-2) Paraffin Wax (Paraffin Wax-150 (trade name) manufactured by Nippon Seiro Co., Ltd.)

(D-3) Microcrystalline Wax (Microwax 180 (trade name) manufactured by JX Nippon Oil & Energy Corporation)

(E) Stabilizer

(E-1) antioxidant (Adeka Stab AO-412S (trade name) manufactured by ADEKA Corporation)

Each component (A)-(E) was formulated according to the formulations (parts by weight) shown in Tables 1-3, then heated at about 145° C. for about 1.5 hours using a universal stirrer, and melt-mixed in Examples and a hot melt adhesive of Comparative Example.

For each of the above hot melt adhesives, the melt viscosity, softening point and adhesion to the paper package and plastic cup using the paper package, and water resistance adhesion.

A method for preparing a sample for evaluation, an evaluation method, and an evaluation criterion are presented below.

<Viscosity Measurement>

The hot melt adhesive was melted at 120° C., 140° C., 160° C. and 180° C., respectively, and after 20 minutes, using a Brookfield viscometer, No. 27 Viscosity was measured with a rotor.

<Measurement of softening point>

The softening point of the hot melt adhesive was measured according to the round ball method (the method described in JAI-7-1999 by the Japan Adhesive Industry Association standard).

<Evaluation of adhesive strength>

(Sample Preparation)

As an attachment (or substrate), a paper package or a plastic cup was coated with a hot melt adhesive in a coating amount of 0.03 to 0.04 g using a hot melt gun. The coating was carried out at a temperature of 180°C. The attachment coated with the hot melt adhesive was placed on a wrapping paper containing a straw through the hot melt adhesive, and then pressed with a finger to obtain a sample for evaluation.

Samples for evaluation of adhesive strength at standard temperature and low temperature were stored at room temperature (23° C.) for 24 hours, and then used for evaluation.

Samples for evaluation of water-resistant adhesive strength were prepared using the above-mentioned samples (the attachment was a paper package and prepared for evaluation of adhesive strength at standard temperature and low temperature). Samples with paper packages attached were further immersed in tap water at room temperature for 12 hours. Before evaluation, tap water on the paper package was removed using a paper towel to obtain a sample for evaluation of water-resistant adhesive strength.

(Test Methods)

Using a universal tensile testing machine (manufactured by Shimadzu Corporation), a peel test was performed at a speed of 300 mm/min on the samples mentioned for evaluation of adhesive strength. For each hot melt adhesive (Example and Comparative Example), three or more samples are measured to obtain each adhesive strength value, and their average value is calculated to be an average adhesive strength (hereinafter referred to as "adhesive strength") referred to) values were obtained. Measurements were carried out at 5°C and 23°C, respectively.

In addition, the detached portion of each sample was visually observed to examine its appearance.

The evaluation criteria of adhesive strength are as follows.

Adhesive strength evaluation

"A" (excellent): The average adhesive strength is 15 N or more.

"B" (good): The average adhesive strength is 8 N or more and less than 15 N.

"C" (poor): Average adhesive strength less than 8 N.

Appearance of the peeled part (this is presented on the right side of the adhesive strength evaluation "A"-"C")

++: Interfacial failure (the surface of the substrate is destroyed)

+: Complex failure including interfacial failure and cohesive failure (both surfaces of substrate and adhesive are destroyed together)

*: cohesive failure (failure in which the adhesive is destroyed)

More preferred are adhesives with higher adhesive strength ("A" is more preferred than "B", "B" is more preferred than "C"). Among adhesives with similar adhesive strength (in adhesives with “A” and among adhesives with “B”), interfacial failure is preferred over cohesive failure.

[Table 1]

[Table 2]

[Table 3]

As shown in Tables 1 and 2, since the hot melt adhesive of Examples 1-12 comprises component (A1): a diblock-containing styrenic block copolymer, they are at low temperature (5°C) and standard temperature (23°C). ) has excellent adhesive strength (to a paper package (or carton) or plastic cup), and further also has excellent water resistance adhesive strength. The hot melt adhesive of the embodiment can be suitably used in a container having a straw, since the adhesive has an excellent balance of the above-mentioned properties.

The hot melt adhesive of Comparative Examples 1-4, as shown in Table 3, compared to the adhesive of Examples 1-12, at low temperature (5° C.) and standard temperature (23° C.) for any attachment (or substrate). Adhesive strength is low. The water-resistant adhesive strength of the comparative adhesive is much lower than that of the Examples. Since the water-resistance adhesive strength of the comparative adhesive is evaluated as "C", it cannot be practically used for a container having a straw.

Thus, as the hot melt adhesive comprises a diblock styrenic block copolymer, it proves that the adhesive is suitable for making containers with straws.

The present invention provides a hot melt adhesive for a container having a straw, a wrapping paper containing a straw obtainable by being coated with the hot melt adhesive, and a container having the straw. The hot melt adhesive according to the present invention has excellent adhesion to paper packages (or cartons) and plastic cups at standard temperatures and low temperatures, and also has excellent water resistance adhesion. Therefore, it is suitable for producing a container having a straw, in particular a container made of paper.

List of reference symbols

1: Container with straw

2: Surface

3: Straw hole

5: Straw

6: Wrapping paper containing straw

Claims (5)

A hot melt adhesive comprising (A) a thermoplastic block copolymer based on a vinylaromatic hydrocarbon and a conjugated diene compound, wherein (A) the thermoplastic block copolymer comprises (A1) component: a styrenic block containing a diblock copolymer A hot melt adhesive comprising a copolymer. The hot melt adhesive according to claim 1, wherein component (A1) comprises a styrenic block copolymer having a styrene content of 20-50 wt% and a diblock copolymer content of 20-80 wt%. The hot melt adhesive according to claim 1 or 2, wherein the (A) thermoplastic block copolymer further comprises component (A2): a triblock styrenic block copolymer. 4. The hot melt adhesive according to any one of claims 1 to 3, wherein the hot melt adhesive further comprises (B) a tackifier resin, (C) a softener and (D) a wax. A container having a straw, wherein the straw is fixed to the container using a hot melt adhesive according to any one of claims 1 to 4.

Images