WO2023162828A1

WO2023162828A1 - Hot melt composition, article, and sealing method

Info

Publication number: WO2023162828A1
Application number: PCT/JP2023/005302
Authority: WO
Inventors: 祐弥沖村; 昌宏須藤; 将成篠田; 優高畑
Original assignee: 東亞合成株式会社
Priority date: 2022-02-24
Filing date: 2023-02-15
Publication date: 2023-08-31

Abstract

The present disclosure provides a hot melt composition wherein: the melt viscosity at 200°C measured by a prescribed method is 10,000-250,000 mPa·s; a value obtained by dividing the melt viscosity value at 200°C by the melt viscosity value at 220°C is 2 or more; the softening point measured by a prescribed method is 130-200°C; the elongation measured by a prescribed method is greater than 500%; and the compression set measured by a prescribed method is 35% or less.

Description

HOT MELT COMPOSITION, ARTICLE AND SEALING METHOD

The present disclosure relates to hot melt compositions, articles, and sealing methods.

EPDM foams made by foaming ethylene-propylene-diene rubber (hereinafter sometimes referred to as EPDM) have been known as sealing materials for various industrial products. EPDM foams are generally produced by foaming EPDM with a foaming agent and cross-linking with a cross-linking agent.

Patent Literature 1 discloses a sealing material. The sealing material disclosed in Patent Document 1 comprises an ethylene-propylene-diene rubber foam. The ethylene-propylene-diene rubber foam is obtained by foaming a rubber composition containing an ethylene-propylene-diene rubber, a foaming agent, a cross-linking agent and a filler. The ethylene-propylene-diene rubber contains an ethylene-propylene-diene rubber having a long-chain branched structure. The foaming agent consists essentially of sodium bicarbonate. The ethylene-propylene-diene rubber foam has an apparent density of 0.15 g/cm ³ or less.

　　Patent Document 1: JP-A-2017-66379

Normally, a certain thickness is required for the sealing material, but in the case of a hot melt composition, there was a problem that it was difficult to apply a thick film and it was not suitable as a sealing material. Therefore, the problem to be solved by the present disclosure is to provide a hot-melt composition that is excellent in thick film coating properties.

Means for solving the above problems include the following aspects.
<1> Based on ASTM D3236-73, Spindle No. The melt viscosity at 200°C measured using SC4-27 is 10,000 mPa s or more and 250,000 mPa s or less, and the melt viscosity at 200°C is divided by the melt viscosity at 220°C. The value is 2 or more, and the softening point measured using silicone oil as a heat medium in accordance with JIS K6863-1994 is 130° C. or more and 200° C. or less,
In accordance with JIS K6251-2017, a test piece punched into a No. 3 dumbbell shape from a sample sheet molded to a thickness of 1 mm is pulled at a speed of 100 mm / min at 23 ° C. The elongation rate is more than 500%, A hot-melt composition conforming to JIS K6262-2013 and having a compression set of 35% or less when a sample molded to a height of 12.5 mm was measured at 70°C for 24 hours at a compression ratio of 25%.
<2> The hot-melt composition of <1> containing a styrene-based elastomer.
<3> The hot melt composition according to <2>, wherein the styrene elastomer is a styrene-ethylene/butylene-styrene block copolymer.
<4> The hot melt composition according to any one of <1> to <3>, further comprising mineral oil.
<5> The hot melt composition according to any one of <1> to <4>, further comprising at least one selected from the group consisting of a tackifying resin and a polyolefin resin.
<6> The hot melt composition according to any one of <1> to <5>, further comprising an antioxidant.
<7> The hot-melt composition according to any one of <1> to <6>, which is a sealing material.
<8> The hot-melt composition according to <7>, which is a sealing material for automobile interior materials.
<9> The hot-melt composition according to <7> or <8>, which is a waterproof, vibration-proof or sound-proof sealing material.
<10> An article comprising a seal portion made of the hot-melt composition according to any one of <1> to <9>.
<11> The article according to <10>, which has a tack suppressing layer on at least a part of the surface of the seal portion.
<12> The article according to <11>, wherein the anti-tack layer contains polyolefin powder, surfactant or silicone oil.
<13> The article according to any one of <10> to <12>, which is an automobile interior material.
<14> The article according to <13>, wherein the automotive interior material is a door trim, pillar, trunk room cover, or door mirror service hole cover.
<15> A sealing method, comprising the step of applying the hot melt composition according to any one of <1> to <9> onto a member to be sealed to form a sealed portion.
<16> The sealing method according to <15>, wherein the hot-melt composition is applied in the form of a bead in the step of forming the seal portion.
<17> The sealing method according to <15> or <16>, further comprising applying a tack inhibitor having a viscosity of 1,000 mPa·s or less at 23° C. to at least part of the surface of the sealing portion.
<18> The sealing method according to <17>, wherein the tack inhibitor is an emulsion composition in which polyolefin powder is dispersed, an aqueous surfactant solution, or silicone oil.

According to one embodiment of the present disclosure, it is possible to provide a hot-melt composition with excellent thick film coating properties.

The description of the constituent elements described below may be made based on representative embodiments of the present disclosure, but the present disclosure is not limited to such embodiments. In the specification of the present application, the term "~" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.
In the numerical ranges described stepwise in this specification, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of the numerical range described in other steps. good. In the numerical ranges described herein, the upper or lower limits of the numerical ranges may be replaced with the values shown in the examples.
The term "step" in this specification is not limited to independent steps, and even if it cannot be clearly distinguished from other steps, it is included in the term as long as the intended purpose of the step is achieved. .
In the present disclosure, "% by mass" and "% by weight" are synonymous, and "parts by mass" and "parts by weight" are synonymous.
In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect.
In the present disclosure, the amount of each component in the composition means the total amount of the above substances present in the composition unless otherwise specified when there are multiple substances corresponding to each component in the composition. do.
The content of the present disclosure will be described in detail below.

(Hot melt composition)
Hot melt compositions according to the present disclosure are manufactured according to ASTM D3236-73, spindle no. The melt viscosity at 200 ° C. measured using SC4-27 (hereinafter also referred to as "melt viscosity (200 ° C.)") is 10,000 mPa s or more and 250,000 mPa s or less, and the melt at 200 ° C. The value obtained by dividing the viscosity value by the melt viscosity value at 220° C. (hereinafter also referred to as “ratio (melt viscosity (200° C.)/melt viscosity (220° C.))”) is 2 or more, and conforms to JIS K6863-1994. Then, the softening point (hereinafter also simply referred to as "softening point") measured using silicone oil as a heat medium is 130 ° C. or higher and 200 ° C. or lower, and conforms to JIS K6251-2017, from a sample sheet molded to a thickness of 1 mm. The elongation rate (hereinafter simply referred to as "elongation rate") when a test piece punched into a No. 3 dumbbell shape is pulled at a speed of 100 mm / min at 23 ° C. is more than 500%, and conforms to JIS K6262-2013. The compression set (hereinafter simply referred to as "compression set") of a sample molded to a height of 12.5 mm was measured at 70°C for 24 hours at a compression ratio of 25%, and is 35% or less.
The hot-melt composition according to the present disclosure can be suitably used as a sealing material, can be more suitably used as a sealing material for automobiles, and can be particularly suitably used as a sealing material for automobile interior materials.
The hot-melt composition according to the present disclosure can be suitably used as a water-stopping, vibration-proof, or sound-proof sealing material, and can be particularly suitably used as a water-stopping, vibration-proof, and sound-proof sealing material.

2. Description of the Related Art Conventionally, synthetic rubber foam (for example, EPDM) coated with an adhesive has been used as a waterproof, antivibration, and soundproof sealing material for automotive parts. The work of fitting the rubber foam into the grooves formed on the automobile parts and setting them must be done manually. Therefore, there was a possibility that productivity would be bad. Furthermore, the adhesive applied to the rubber foam has a release paper called a separator. Therefore, there is a possibility that waste (that is, release paper) is generated after the work of attaching the sealing material.
Furthermore, conventional hot-melt adhesives do not have sufficient thick film applicability.

As a result of intensive studies by the present inventors, it was found that the hot melt composition according to the present disclosure has excellent thick-film coating properties due to the configuration described above.
This effect is presumed to be due to the following reasons, but is not limited thereto.
When the hot-melt composition has the above structure, the melt viscosity at 220° C. is low, and the melt viscosity is greatly improved by cooling after the hot-melt application. As a result, even if the applied material is a thick film, the applied material is prevented from being deformed or spread by wetting. Therefore, it is presumed that the hot-melt composition is excellent in thick film coating properties.

The hot-melt composition according to the present disclosure is also excellent in dischargeability (bead coatability) and water stoppage.

Below, the details of each constituent element related to this disclosure will be described.

<Melt viscosity at 200°C>
In the hot melt composition according to the present disclosure, the melt viscosity (200° C.) is 10,000 mPa s or more and 250,000 mPa s or less, and from the viewpoint of dischargeability and thick film coating properties, it is 15,000 mPa s or more. It is preferably 200,000 mPa·s or less, more preferably 20,000 mPa·s or more and 180,000 mPa·s or less, and particularly preferably 30,000 mPa·s or more and 160,000 mPa·s or less.

<Melt viscosity at 220°C>
The hot-melt composition according to the present disclosure conforms to ASTM D3236-73 and spindle no. The melt viscosity at 220° C. measured using SC4-27 (hereinafter also referred to as “melt viscosity (220° C.)”) is 1,000 mPa s or more and 100, It is preferably 000 mPa·s or less, more preferably 2,000 mPa·s or more and 80,000 mPa·s or less, and particularly preferably 5,000 mPa·s or more and 50,000 mPa·s or less.

<Value obtained by dividing the melt viscosity value at 200°C by the melt viscosity value at 220°C>
In the hot melt composition according to the present disclosure, the ratio (melt viscosity (200° C.)/melt viscosity (220° C.)) is 2 or more, and from the viewpoint of dischargeability, thick film coating property, and water stoppage, 2 It is preferably 30 or less, more preferably 2.5 or more and 10 or less, still more preferably 3.0 or more and 8 or less, and particularly preferably 3.5 or more and 6 or less.

Each of the melt viscosity (200° C.) and the melt viscosity (220° C.) of the hot-melt composition in the present disclosure is measured according to ASTM D3236-73, Spindle No. Measured using SC4-27.
More specifically, the melt viscosity (200° C.) is determined according to ASTM D3236-73 using a Brookfield viscometer with spindle No. Obtained by measuring the melt viscosity at a measurement temperature of 200° C. using SC4-27. Melt viscosity (220°C) is obtained in the same manner as melt viscosity (200°C) except that the measurement temperature is changed to 220°C.

<Softening point>
The hot-melt composition according to the present disclosure has a softening point of 130° C. or higher and 200° C. or lower, preferably 140° C. or higher and 190° C. or lower, and 150° C. or higher and 180° C. or lower, from the viewpoint of dischargeability and thick film coating properties. ° C. or less, and particularly preferably 155° C. or higher and 180° C. or lower.

The softening point of the hot-melt composition in the present disclosure is measured according to JIS K6863-1994 using silicone oil as a heat medium.
More specifically, the softening point of the hot-melt composition in the present disclosure is obtained by measuring the softening point by the R&B (ring & ball) method using silicone oil as a heat medium according to JIS K 6863.

<Elongation rate>
In the hot-melt composition according to the present disclosure, the elongation rate is more than 500%, and from the viewpoint of ejection property, thick film coating property, and water stoppage, it is preferably more than 500% and 10,000% or less. , more preferably 1,000% or more and 5,000% or less.

The elongation percentage of the hot-melt composition in the present disclosure is determined according to JIS K6251-2017, and a test piece punched into a No. 3 dumbbell shape from a sample sheet molded to a thickness of 1 mm is subjected to a tensile test at a speed of 100 mm / min at 23 ° C. is obtained by measuring the elongation rate.

<Composition>
The composition of the hot melt composition according to the present disclosure is not particularly limited as long as each melt viscosity, softening point and elongation satisfy the above ranges. The hot-melt composition preferably contains a styrene-based elastomer from the viewpoints of thermal cycle durability, adhesiveness and handleability, as well as from the viewpoints of adhesiveness, jettability, thick film coating properties and water stopping properties. More preferably, the hot-melt composition contains a styrene-based elastomer, mineral oil, and at least one selected from the group consisting of a tackifier (also referred to as a "tackifier") and a polyolefin resin. More preferably, the hot-melt composition contains a styrene-based elastomer, mineral oil, and a polyolefin resin.

-Styrene Elastomer-
The hot-melt composition according to the present disclosure preferably contains a styrene-based elastomer from the viewpoint of adhesiveness, jettability, thick-film coating properties, and water stoppage.
In addition, the “elastomer” in the present disclosure is a polymer having rubber elasticity at room temperature.
The styrene-based elastomer is not particularly limited, and known materials can be used. Examples include styrene-butadiene copolymer, epoxy-modified styrene-butadiene copolymer, styrene-butadiene-styrene block copolymer, styrene - Ethylene/propylene-styrene block copolymer (hereinafter referred to as "SEPS"), styrene-ethylene/butylene-styrene block copolymer (hereinafter referred to as "SEBS"), styrene-isoprene/butadiene-styrene block copolymer polymers, and styrene-isoprene-styrene block copolymers.
Among them, the styrene-based elastomer preferably contains at least one selected from the group consisting of SEPS and SEBS from the viewpoint of adhesiveness, ejection properties, thick film coating properties, and water stoppage, and contains SEBS. is particularly preferred.
The styrene-based elastomer is preferably a block copolymer from the viewpoints of adhesiveness, jettability, thick film coating properties, and water stoppage.
Block copolymers used in the present disclosure may be linear or radial.

Furthermore, the hot-melt composition according to the present disclosure may contain one type of the styrene-based elastomer, or may contain two or more types.
The content of the styrene-based elastomer is preferably 1% by mass or more and 80% by mass or less with respect to the total mass of the hot-melt composition from the viewpoint of adhesiveness, jettability, thick film coating properties, and water stoppage. It is preferably 2% by mass or more and 50% by mass or less, and particularly preferably 5% by mass or more and 30% by mass or less.

The weight average molecular weight of the styrene elastomer is preferably 10,000 to 500,000, more preferably 30,000 to 400,000, even more preferably 150,000 to 300,000. As used herein, the term "weight average molecular weight" is a value obtained by converting the molecular weight measured by gel permeation chromatography (hereinafter also referred to as "GPC") into polystyrene.

-Mineral oil-
The hot-melt composition according to the present disclosure preferably contains mineral oil from the viewpoint of adhesiveness, jettability, thick film coating properties, and handling properties.
"Mineral oil" in this disclosure refers to hydrocarbon compounds. Mineral oils are preferably hydrocarbon compounds derived from underground resources such as petroleum, natural gas, and coal.
The mineral oil is preferably a liquid compound at 25°C.
Furthermore, the mineral oil is preferably a compound that is compatible with the styrene-based elastomer, the tackifier or amorphous polyolefin to be described later, from the viewpoints of adhesiveness, jettability, thick film coating properties, and handleability.

Preferred examples of the mineral oil include aromatic (aromatic) hydrocarbon compounds, naphthenic (cyclocyclic) hydrocarbon compounds, paraffin (aliphatic) hydrocarbon compounds, and mixtures thereof.

A commercial item can also be used as said mineral oil.
Examples of commercially available mineral oils include Process Oil PW90 (manufactured by Idemitsu Kosan Co., Ltd.), Sunpure NX46, Sunpure NX90, and Sunpure N90-A (manufactured by Nippon Sun Oil Co., Ltd.).

The mineral oil may be used singly or in combination of two or more.
The content of the mineral oil is preferably 10% by mass or more and 95% by mass or less with respect to the total mass of the hot-melt composition from the viewpoints of adhesiveness, ejection properties, thick film coating properties, and handleability. It is more preferably 20% by mass or more and 90% by mass or less, still more preferably 30% by mass or more and 90% by mass or less, and particularly preferably 60% by mass or more and 90% by mass or less.
The mass ratio of the content of the mineral oil to the content of the styrene elastomer (mineral oil/styrene elastomer) in the hot-melt composition according to the present disclosure, from the viewpoint of, it is preferably 1 or more and 15 or less, more preferably 2 or more and 10 or less, further preferably 2 or more and 9 or less, and particularly preferably 6 or more and 9 or less.

- Tackfire -
The hot-melt composition according to the present disclosure preferably contains a tackifier (tackifying resin) from the viewpoints of adhesiveness, jettability, thick film coating properties, and water stoppage.
Examples of the tackifier include petroleum resins; rosin derivatives such as rosin ester, gum rosin, tall oil rosin, hydrogenated rosin ester, maleated rosin, and disproportionated rosin ester; terpene phenol resin, α-pinene, β-pinene. , terpene-based resins mainly composed of limonene, etc.; coumarone-indene-based resins; hydrogenated aromatic copolymers; styrene-based resins; phenol-based resins; xylene-based resins;

Among them, in the hot melt composition according to the present disclosure, from the viewpoint of adhesiveness, ejection property, thick film coating property, and water stoppage, the tackifier is a group consisting of petroleum resins, rosin derivatives, and terpene-based resins. It preferably contains at least one compound selected from More preferably, the hot melt composition contains at least one compound selected from the group consisting of C5 petroleum resins, rosin esters, and terpene phenolic resins. More preferably, the hot melt composition comprises C5 petroleum resin. It is particularly preferred that the hot melt composition comprises a C5 petroleum resin and a rosin ester. Most preferably the hot melt composition comprises a C5 petroleum resin, a rosin ester and a terpene phenolic resin.

"C5 petroleum resin" is a hydrocarbon resin obtained by polymerizing the C5 fraction produced by decomposing naphtha. The C5 fraction includes, for example, isoprene, cyclopentene, piperylene, and their multimers.

The tackifier may be used singly or in combination of two or more.
The content of the tackifier is preferably 1% by mass or more and 70% by mass or less with respect to the total mass of the hot-melt composition from the viewpoint of adhesiveness, jettability, thick film coating properties, and water stoppage. , more preferably 10% by mass or more and 65% by mass or less, still more preferably 20% by mass or more and 60% by mass or less, and particularly preferably 25% by mass or more and 55% by mass or less.
In one embodiment, the tackiness of the hot melt composition can be suppressed when the tackifier content is low. In the case of suppressing tack, the content of the tackifier is preferably 30% by mass or less, more preferably 20% by mass or less, more preferably 10% by mass, relative to the total mass of the hot-melt composition. It is particularly preferably below, and may be 0% by mass.
The mass ratio of the content of the tackifier to the content of the styrene elastomer (tackifier/styrene elastomer) in the hot-melt composition according to the present disclosure is From the viewpoint of water stoppage, it is preferably 0.5 or more and 8.0 or less, more preferably 1.0 or more and 6.0 or less.

-Polyolefin resin-
The hot-melt composition according to the present disclosure preferably contains a polyolefin resin from the viewpoints of adhesiveness, jettability, thick-film coating properties, and water stoppage.

Polyolefin resins include polypropylene, ethylene/propylene copolymers, copolymers of propylene and other α-olefins, and ethylene, propylene and other α-olefins. Specific examples of polyolefin resins include propylene/ethylene copolymers, propylene/1-butene copolymers, ethylene/propylene/1-butene terpolymers, and propylene/1-hexene/1-octene terpolymers. , propylene/1-hexene/4-methyl-1-pentene terpolymer, propylene/1-hexene/4-methyl-1-pentene terpolymer, and poly(1-butene). .

The said polyolefin resin may be used individually by 1 type, or may use 2 or more types together.
The content of the polyolefin resin is 0.1% by mass or more and 20% by mass or less with respect to the total mass of the hot melt composition from the viewpoint of adhesiveness, ejection property, thick film coating property, and water stoppage. is preferred, more preferably 0.5% by mass or more and 10% by mass or less, and particularly preferably 1% by mass or more and 8% by mass or less.
The mass ratio of the content of the polyolefin resin to the content of the styrene elastomer (polyolefin resin/styrene elastomer) in the hot-melt composition according to the present disclosure is From the viewpoint of water stoppage, it is preferably 0.05 or more and 1.0 or less, more preferably 0.1 or more and 0.8 or less, and particularly preferably 0.2 or more and 0.5 or less.

-Antioxidant-
The hot-melt composition according to the present disclosure preferably contains an antioxidant from the viewpoint of adhesiveness, jettability, thick-film coating properties, and storage stability.
The antioxidant is not particularly limited, and known antioxidants can be used, for example, phenol antioxidants, amine antioxidants, phosphorus antioxidants, sulfur-containing antioxidants, hydroquinone antioxidants Examples include antioxidants, quinoline antioxidants, hydrazines, and urea antioxidants.
Among these antioxidants, phenolic antioxidants are preferred, and hindered phenolic antioxidants are more preferred.

Examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol (BHT), 2,2'-methylenebis(4-methyl-6-t-butylphenol), 4,4' -butylidenebis(3-methyl-6-t-butylphenol), stearyl-β-(3,5-di-t-butyl-4-hydroxylphenol)propionate, tetrakis[methylene-3-(3',5'-di -t-butyl-4′-hydroxyphenyl)propionate]methane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-4-hydroxybenzyl)benzene, 1,1, 3-tris(2-methyl-4-hydroxy-5-t-butylphenol)butane, pentaerythyltetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,1- bis(4-oxyphenyl)cyclohexane, dialkylphenol sulfides, alkylphenol condensates, styrenated phenols, and the like.
Among these, phenolic antioxidants are hindered phenolic antioxidants that have one or two t-butyl groups on the aromatic ring adjacent to the carbon atom to which the phenolic hydroxy group is attached. It is preferably an antioxidant, more preferably pentaerythyl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate].
Examples of the amine antioxidant include N,N'-di-2-naphthyl-p-phenylenediamine, phenyl-α-naphthylamine, phenyl-β-naphthylamine, 4,4'-dimethoxydiphenylamine, N,N '-diphenyl-p-phenylenediamine, N-phenyl-N'-cyclohexyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, aldol-α-naphthylamine, 4,4'-diaminodiphenylmethane , acetaldehyde aniline, and reaction products of diphenylamine and acetone.

The antioxidants may be used singly or in combination of two or more.
The content of the antioxidant is preferably 0.001% by mass or more and 10% by mass or less with respect to the total mass of the hot melt composition from the viewpoint of thermal cycle durability and storage stability. It is more preferably 0.01% by mass or more and 5% by mass or less, and particularly preferably 0.05% by mass or more and 1% by mass or less.

-Other ingredients-
Hot melt compositions according to the present disclosure may further contain other ingredients.
Other components include, for example, fillers, processing aids, flame retardants, flow modifiers, deodorants, antibacterial agents, adhesion improvers, and pigments.

Fillers include fumed silica, surface-treated fumed silica, precipitated silica, diatomaceous earth, quartz powder, calcium carbonate, carbon black, and the like.
When the hot-melt composition according to the present disclosure contains a filler, it is possible to improve the heat resistance, elastic modulus, blocking resistance, etc. of the hot-melt composition according to the present disclosure.
Examples of processing aids include low-viscosity silicone oils having terminal silanol groups or alkoxysilyl groups, resins, and silane compounds.
Examples of heat resistance improvers include iron octoate, iron oxide, Mn-based compounds, Ni-based compounds, Cu-based compounds, Zr-based compounds, Ce-based compounds, W-based compounds, titanium oxide, and fumed titanium oxide.
In order to further enhance the flame retardant effect, iron oxide, titanium oxide, carbon black, phosphorus compounds, nitrogen compounds, and the like may be used as flame retardant agents.

The other components may be used singly or in combination of two or more.
The content of the other components is not particularly limited, but is preferably 20% by mass or less, more preferably 10% by mass or less, relative to the total mass of the hot-melt composition.

(Goods)
Articles of the present disclosure comprise an adhesive or seal portion comprising a hot melt composition of the present disclosure. The article according to the present disclosure preferably comprises a seal portion made of the hot melt composition according to the present disclosure.
The hot-melt composition according to the present disclosure can be suitably used in various articles, for example, as a sealing material, a vibration-proof material, a sound-absorbing material, a sound-insulating material, a dust-proof material, a heat-insulating material, a shock-absorbing material, or a water-stopping material. can.
The shape, size and number of the sealing portions are not particularly limited and can be appropriately selected as desired.
From the viewpoint of further exhibiting the effects of the present disclosure, the sealing portion is preferably a sealing portion formed by applying the hot-melt composition in a bead shape (string shape).
The article is not particularly limited, and can be applied to various articles, and can be suitably used for automobile members, electrical equipment, building materials, and the like.
The material of the article is not particularly limited, but preferably includes metal, resin, wood, stone, and the like.
Among them, the article is preferably an automobile member, and more preferably an automobile interior material.
More preferably, the automobile interior material is a door trim, pillar, trunk room cover, or door mirror service hole cover.

The article according to the present disclosure preferably has a tack-suppressing layer on at least a part of the surface of the seal portion from the viewpoint of tack-suppressing properties.
The surface tack of hot melt compositions according to the present disclosure can be strong. In this case, when a plurality of articles coated with the hot-melt composition are stacked with the surface coated with the hot-melt composition facing upward, the hot-melt composition applied to one article sticks to the back surface of the other article. Sometimes. That is, so-called blocking may occur.
The present inventors have found that by forming the anti-tack layer on the article according to the present disclosure, blocking can be eliminated and an article with high productivity can be obtained.
The anti-tack layer is not particularly limited as long as it can suppress tack, but preferably contains polyolefin powder, surfactant or silicone oil.
The polyolefin powder, surfactant and silicone oil are not particularly limited, but known ones, especially known release agents, can be suitably used.
Although the thickness of the tack-suppressing layer is not particularly limited, it is preferably 0.01 μm to 100 μm.

The article according to the present disclosure may have the tack suppressing layer on at least a part of the surface of the seal portion, or may have the tack suppressing layer on the entire surface of the seal portion. The article preferably has at least the anti-tack layer on the exposed portion of the seal portion.

(Sealing method and article manufacturing method)
A sealing method according to the present disclosure includes a step of applying a hot melt composition according to the present disclosure onto a member to be sealed to form a sealed portion.
A method for manufacturing an article according to the present disclosure includes a step of applying a hot melt composition according to the present disclosure onto a member to be sealed to form a sealed portion.
Preferred aspects of the method of manufacturing an article according to the present disclosure are the same as those of the sealing method of the present disclosure unless otherwise specified.

The material, shape and size of the member to be sealed are not particularly limited, and may be appropriately selected as desired.
The heating temperature of the hot-melt composition in the step of forming the seal portion is preferably 170°C to 300°C, more preferably 180°C to 250°C, even more preferably 185°C to 240°C. More preferably, it is particularly preferably from 190°C to 225°C.
The means for heating the hot-melt composition is not particularly limited, and known means such as heaters and hot-melt applicators can be used.
The means for applying the hot-melt composition is not particularly limited, and known application means such as a hot-melt applicator can be used.
In the step of forming the seal portion, the method of applying the hot-melt composition is not particularly limited, but from the viewpoint of further exhibiting the effects of the present disclosure, it is preferable to apply the hot-melt composition in a bead shape. .
Furthermore, in the step of forming the seal portion, from the viewpoint of further exhibiting the effects of the present disclosure, it is preferable to apply the hot-melt composition to a thickness of 1 mm or more, and the hot-melt composition is applied to a thickness of 4 mm or more. It is preferable to apply it evenly. Although the upper limit is not particularly limited, it is preferably 50 mm or less.

The sealing method according to the present disclosure may further include a step of applying a tack inhibitor having a viscosity of 1,000 mPa·s or less at 23° C. to at least a portion of the surface of the seal portion, from the viewpoint of tack suppression properties. preferable.
Although the tack inhibitor is not particularly limited, it is preferably an emulsion composition in which polyolefin powder is dispersed, an aqueous surfactant solution, or silicone oil, from the viewpoint of tack inhibitory properties.
The polyolefin powder, surfactant and silicone oil are not particularly limited, but known ones, especially known release agents, can be suitably used.
The thickness of the coating of the tack inhibitor is not particularly limited, but is preferably from 0.01 μm to 100 μm.

The sealing method according to the present disclosure may have other steps than those described above.
Other steps are not particularly limited, and known steps can be used.

The present disclosure will be specifically described below based on examples. However, the present disclosure is not limited by these examples. In the following, "parts" and "%" mean "mass parts" and "mass%", respectively, unless otherwise specified.

(Examples 1 to 9 and Comparative Examples 1 to 3)
<Preparation of hot melt composition>
Each component shown in Table 1 was mixed in the amount shown in Table 1 with heating using an MS open type kneader (manufactured by Moriyama Co., Ltd.) set at 250° C. for about 30 minutes. Hot melt compositions of Example 9 and Comparative Examples 1 to 3 were prepared.

<Melt viscosity measurement>
According to ASTM D3236-73, spindle no. Melt viscosity was measured using SC4-27. Measurement temperatures were 200°C and 220°C.

<Measurement of softening point>
Measured according to JIS K 6863-1994 by the R&B method using silicone oil as a heat medium.

<Measurement of elongation>
According to JIS K 6152-2017, a tensile test was performed at 23° C. at a speed of 100 mm/min using a No. 3 dumbbell-shaped test piece punched out from a resin sheet formed by molding a hot-melt composition to a thickness of 1 mm.
A: Elongation rate exceeding 500% F: Elongation rate of 500% or less

<Evaluation of Ejectability (Bead Coatability) and Thick Film Coatability>
A hot-melt composition heated and melted at 220° C. by a hot-melt applicator was bead-coated to a polypropylene plate of 25 mm width, 125 mm length and 2 mm thickness in a width of 10 mm and thickness of 5 mm.
The ejection properties and thick film coating properties at that time were evaluated according to the following criteria.
-Ejectability evaluation-
A: Ejectable F: Unejectable -Evaluation of thick film coating-
A: Leveling of the hot-melt composition is suppressed after bead application, and the thickness is 4 mm or more B: Leveling of the hot-melt composition is suppressed after bead application, and the thickness is 3 mm to less than 4 mm F: Hot after bead application The melt composition is leveled and its thickness is less than 3 mm

<Evaluation of ball tackiness (tack suppression property)>
Based on JIS Z0237-2009, it was evaluated by the following method.
A hot melt adhesive was adjusted to a thickness of 200 μm on a polyethylene terephthalate (PET) sheet with a thickness of 100 μm, and the following tack inhibitor was applied with a brush according to the description in Table 1 to suppress tackiness to a thickness of 5 μm. formed a layer.
Tack inhibitor A: polyolefin emulsion remover (Chemipearl W100 manufactured by Mitsui Chemicals, Inc.)
Tack inhibitor B: Surfactant aqueous solution (Mold 57 manufactured by Lion Specialty Chemicals Co., Ltd.)
Tack inhibitor C: silicone oil (KF-96 manufactured by Shin-Etsu Chemical Co., Ltd.)
Next, the ball tack number at 23° C. was evaluated using a ball tack tester set at an inclination angle Θ of 30°.
A: Ball tack value is 1
B: Ball tack value is 2
F: Ball tack value is 3 or more

<Water stopping evaluation>
A hot-melt composition heated and melted at 220° C. with a hot-melt applicator was applied to a 20 cm square polypropylene plate in a U-shape of 10 cm×10 cm×10 cm with a bead of 10 mm width and 5 mm thickness. After that, a polypropylene plate of 20 cm square was superimposed and fixed so that the compressibility of the hot-melt composition was 50%. Next, water was poured into the U-shaped interior so that the water depth was 5 mm, and the interior was held for 30 minutes, and the presence or absence of water leakage was confirmed.
A: No water leakage F: Water leakage

<Compression set>
According to JIS K6262-2013, a circular sample with a diameter of 29 mm and a height of 12.5 mm was stored at a compression rate of 25% at 70 ° C. for 24 hours, and the initial height of the sample and the height after decompression Compression set was calculated.
A: compression set is 35% or less F: compression set is more than 35%

In Comparative Example 2 in Table 1, the melt viscosity at 220°C was not measured because the melt viscosity at 200°C exceeded the measurement limit.
"-" in the evaluation of Comparative Examples 2 and 3 in Table 1 indicates that ejection was not possible and evaluation was not possible.

The details of the abbreviations in Table 1 are described below.
-Styrene Elastomer-
Kraton G1651: Linear type styrene-ethylene/butylene-styrene block copolymer (SEBS), manufactured by Kraton Corporation-mineral oil-
Process oil PW-90: manufactured by Idemitsu Kosan Co., Ltd., paraffin (aliphatic)-based process oil -tackifier (tackifying resin)-
Alcon P-140: Hydrogenated petroleum resin, manufactured by Arakawa Chemical Industries, Ltd., softening point 140 ° C ± 5 ° C - polyolefin resin -
VESTOPLAST888: ethylene/propylene/1-butene terpolymer, manufactured by Evonik Prime Polypro E239: random polypropylene polymer, manufactured by Prime Polymer -Antioxidant-
Antioxidant: hindered phenolic antioxidant, Sonnox 1010, manufactured by Songwon Industrial

As is clear from the results in Table 1, the hot-melt compositions of Examples 1 to 9, which are the hot-melt compositions according to the present disclosure, have excellent thick-film coating properties as compared to Comparative Examples 1 to 3. I understand.
Furthermore, it can be seen that the hot-melt composition according to the present disclosure is excellent in jettability and water stoppage.

The disclosure of Japanese Patent Application 2022-027157 filed on February 24, 2022 is incorporated herein by reference in its entirety.
All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein by reference.

Claims

According to ASTM D3236-73, spindle no. The melt viscosity at 200 ° C. measured using SC4-27 is 10,000 mPa s or more and 250,000 mPa s or less,
The value obtained by dividing the melt viscosity value at 200 ° C. by the melt viscosity value at 220 ° C. is 2 or more,
According to JIS K6863-1994, the softening point measured using silicone oil as a heat medium is 130 ° C. or higher and 200 ° C. or lower,
In accordance with JIS K6251-2017, a test piece punched into a No. 3 dumbbell shape from a sample sheet molded to a thickness of 1 mm is pulled at a speed of 100 mm / min at 23 ° C. The elongation rate is more than 500%,
A hot melt composition conforming to JIS K6262-2013 and having a compression set of 35% or less when a sample molded to a height of 12.5 mm was measured at 70° C. for 24 hours at a compression rate of 25%.
The hot-melt composition according to claim 1, which contains a styrene-based elastomer.
The hot melt composition according to claim 2, wherein the styrene-based elastomer is a styrene-ethylene/butylene-styrene block copolymer.
The hot melt composition according to claim 1, further comprising mineral oil.
The hot melt composition according to claim 1, further comprising at least one selected from the group consisting of a tackifying resin and a polyolefin resin.
The hot melt composition according to any one of claims 1 to 5, further comprising an antioxidant.
The hot melt composition according to claim 1, which is a sealing material.
The hot melt composition according to claim 7, which is a sealing material for automobile interior materials.
The hot-melt composition according to claim 7, which is a waterproof, vibration-proof or sound-proof sealing material.
An article comprising a sealing portion made of the hot melt composition according to any one of claims 1 to 9.
The article according to claim 10, which has a tack-suppressing layer on at least a part of the surface of the seal portion.
The article according to claim 11, wherein the tack-suppressing layer contains polyolefin powder, surfactant or silicone oil.
The article according to claim 10, wherein the article is an automobile interior material.
The article according to claim 13, wherein the automotive interior material is a door trim, pillar, trunk room cover, or door mirror service hole cover.
A sealing method comprising the step of applying the hot-melt composition according to claim 1 onto a member to be sealed to form a sealed portion.
The sealing method according to claim 15, wherein the hot-melt composition is applied in the form of a bead in the step of forming the sealing portion.
The sealing method according to claim 15, further comprising the step of applying a tack inhibitor having a viscosity of 1,000 mPa·s or less at 23°C to at least part of the surface of the sealing portion.
The sealing method according to claim 17, wherein the tack inhibitor is an emulsion composition in which polyolefin powder is dispersed, a surfactant aqueous solution, or silicone oil.