JP4682595B2 - Hot melt adhesive composition - Google Patents

Description

  The present invention relates to a hot melt adhesive composition. Specifically, the present invention relates to a hot-melt adhesive composition that is excellent in low-temperature flexibility and has a long open time (bondable time).

Hot melt adhesives are widely used in the fields of bookbinding, box making / sealing of cardboard / carton cases, assembly of packaging containers, production of building materials such as plywood, and parts assembly of electronic parts / sanitary products.
For example, JP-A-7-48552 discloses a hot melt adhesive having a good bond strength at high and low temperatures with low viscosity, fast curing speed and thermal stability, machinability and aesthetics. A hot melt adhesive composition comprising an ethylene n-butyl acrylate copolymer, a specific tackifier resin, a high melting point synthetic wax and a stabilizer is described.
Japanese Patent Application Laid-Open No. 2000-17243 discloses a hot melt that can be applied at a low temperature, has a low heating temperature to be bonded by thermal activity, has excellent adhesion performance and creep resistance, has flexibility, and has good workability. As an adhesive composition, the melt flow rate is in a specific range, the temperature of the maximum peak of the elution curve is in a specific range, the peak height and the peak width are in a specific relationship, and the Vicat softening point is A hot melt adhesive composition containing a base polymer consisting of a copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms in a specific range and a tackifier is described.

Japanese Patent Laid-Open No. 7-48552 JP 2000-17243 A

However, even when the hot melt adhesive composition described in the above publications is used, the hot melt adhesive composition may have a low low temperature flexibility or a short open time (adhesive time). Improvement of low temperature flexibility and extension of open time (bondable time) have been demanded.
Under such circumstances, the problem to be solved by the present invention, that is, an object of the present invention is to provide a hot melt adhesive composition having excellent low-temperature flexibility and a long open time (adhesive time). .

That is, the present invention is a hot melt adhesive composition containing the following component (A1), component (A2), component (B) and component (C), wherein the sum of component (A1) and component (A2) is When the content is 100% by weight, the content of the component (A1) is 1 to 99% by weight, the content of the component (A2) is 99 to 1% by weight, and the total of the components (A1) and (A2) is 100. The content of the component (B) is 10 to 200 parts by weight and the content of the component (C) is 10 to 100 parts by weight with respect to parts by weight.
Component (A1): When the total amount of component (A1) is 100% by weight, the content of repeating units derived from ethylene is 85 to 50% by weight, and the content of repeating units derived from unsaturated carboxylic acid esters Ethylene-unsaturated carboxylic acid ester copolymer component (A2) having an amount of 15 to 50% by weight and a melt flow rate of 100 to 3000 g / 10 min: ethylene-α produced using a metallocene catalyst An ethylene-α-olefin copolymer component (B) having a melt flow rate of 50 to 2000 g / 10 min and a density of 860 to 930 kg / m ³ : tackifying resin component ( C): Wax

  According to the present invention, a hot melt adhesive composition having excellent low temperature flexibility and a long open time (adhesive time) can be obtained.

  Component (A1) used in the present invention is an ethylene-unsaturated carboxylic acid ester copolymer. As unsaturated carboxylic acid ester used for this copolymer, alkyl ester of unsaturated carboxylic acid, such as acrylic acid and methacrylic acid, can be mentioned, for example.

  As the ethylene-unsaturated carboxylic acid ester copolymer of the component (A1) of the present invention, for example, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer and At least one polymer selected from ethylene-ethyl methacrylate copolymers is preferably used.

When the total amount of the component (A1) is 100% by weight, the content of the repeating unit derived from ethylene of the ethylene-unsaturated carboxylic acid ester copolymer of the component (A1) is 85 to 50% by weight and is unsaturated. The content of repeating units derived from carboxylic acid esters is 15 to 50% by weight. The content of repeating units derived from unsaturated carboxylic acid esters is preferably 17 to 45% by weight, more preferably 20 to 40% by weight. If the content of the repeating unit derived from the unsaturated carboxylic acid ester is too small, the flexibility may be inferior, and if the content is too large, the heat resistance may be inferior.
In addition, content of the repeating unit induced | guided | derived from unsaturated carboxylic acid ester is measured with an infrared spectrophotometer.

  The melt flow rate of the ethylene-unsaturated carboxylic acid ester copolymer of component (A1) is 100 to 3000 g / 10 minutes, preferably 150 to 2500 g / 10 minutes, more preferably 200 to 2000 g / 10 minutes. It is. If the melt flow rate is too small, the workability may be inferior when applying the hot melt adhesive, and if the melt flow rate is too large, the low-temperature flexibility may be inferior. In addition, the melt flow rate of a component (A1) is measured on condition of temperature 190 degreeC and load 21.18N according to JISK7210.

  The production method of the component (A1) is not particularly limited, and examples thereof include a known liquid phase polymerization method and a high pressure radical polymerization method. As a method for producing the component (A1) by the high-pressure radical polymerization method, generally, a tank reactor or a tube reactor is used, under the conditions of a polymerization pressure of 140 to 300 MPa and a polymerization temperature of 100 to 300 ° C. in the presence of a radical generator. The method of copolymerizing ethylene and unsaturated carboxylic acid ester is mentioned below. Further, for the adjustment of the melt flow rate, hydrocarbons such as hydrogen, methane and ethane can be used as molecular weight regulators.

  The ethylene-α-olefin copolymer produced using the metallocene catalyst of component (A2) used in the present invention is a copolymer of ethylene and one or more α-olefins. The α-olefin is preferably an α-olefin having 3 to 12 carbon atoms, such as propylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1 or decene-1. Is mentioned. More preferred is propylene, butene-1, hexene-1 or octene-1, and still more preferred is butene-1 or hexene-1.

  Examples of the ethylene-α-olefin copolymer produced using the metallocene catalyst of component (A2) include ethylene-propylene copolymer, ethylene-butene-1 copolymer, and ethylene-4-methylpentene. -1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, ethylene-propylene-butene-1 copolymer, etc., preferably ethylene-propylene copolymer, ethylene- A butene-1 copolymer, an ethylene-hexene-1 copolymer, or an ethylene-octene-1 copolymer, more preferably an ethylene-butene-1 copolymer or an ethylene-hexene-1 copolymer.

  The melt flow rate of the ethylene-α-olefin copolymer produced using the metallocene catalyst of component (A2) is 50 to 2000 g / 10 minutes, preferably 80 to 1500 g / 10 minutes, more preferably. Is 150 to 1000 g / 10 min. If the melt flow rate is too small, the workability may be inferior when applying the hot melt adhesive, and if the melt flow rate is too large, the low-temperature flexibility may be inferior. In addition, the melt flow rate of a component (A2) is measured on condition of temperature 190 degreeC and load 21.18N according to JISK7210.

The density of the ethylene-α-olefin copolymer produced using the metallocene catalyst of component (A2) is 860 to 930 kg / m ³ , preferably 865 to 920 kg / m ³ , more preferably 870. ˜900 kg / m ³ . If the density is too small, the heat resistance may be inferior, and if the density is too large, the flexibility may be inferior. In addition, the density of a component (A2) is measured on the conditions without annealing according to JISK6760.

  The ethylene-α-olefin copolymer produced using the metallocene catalyst of component (A2) is produced by a known polymerization method using the metallocene catalyst. Examples of the metallocene catalyst include a catalyst composed of a metallocene complex and an aluminoxane, a catalyst composed of a metallocene complex and an organoaluminum compound and / or a boron compound, and the like. Specifically, dimethylsilylene (tetramethylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dichloride, triisobutylaluminum and N, N-dimethyl described in JP-A-9-87313 Catalyst systems comprising anilinium (pentafluorophenyl) borate, and dimethylsilylene (tetramethylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dimethoxide described in JP-A-10-259211 And a catalyst system comprising triisobutylaluminum and N, N-dimethylanilinium (pentafluorophenyl) borate. Examples of the polymerization method of component (B) include a solution polymerization method, a slurry polymerization method, a high pressure polymerization method, and a gas phase polymerization method, and a gas phase polymerization method or a high pressure ion polymerization method is preferable.

As content of a component (A1) and a component (A2), when the sum total of a component (A1) and a component (A2) is 100 weight%, content of a component (A1) is 1-99 weight%, The content of component (A2) is 99 to 1% by weight, preferably the content of component (A1) is 10 to 90% by weight, and the content of component (A2) is 90 to 10% by weight. More preferably, the content of the component (A1) is 20 to 80% by weight, and the content of the component (A2) is 80 to 20% by weight. If the content of component (A1) is too low (the content of component (A2) is too high), the open time (adhesive time) may be shortened, and the content of component (A1) is too high (component If the content of (A2) is too small), the low-temperature flexibility may be inferior.

  The tackifying resin of component (B) used in the present invention is selected from rosin resins, polyterpene resins, synthetic petroleum resins, coumarone resins, phenol resins, xylene resins, styrene resins and isoprene resins. Mention may be made of at least one resin.

  Examples of rosin resins include natural rosin, polymerized rosin, partially and fully hydrogenated rosin, esterified products of these various rosins (glycerin ester, pentaerythritol ester, ethylene glycol ester, methyl ester, etc.), disproportionate, and fumarate Lysates or rosin derivatives in which these are appropriately combined.

  Examples of the polyterpene resin include homopolymers or copolymers of cyclic terpenes (α-pinene, β-pinene, dipentene, etc.); and various terpenes and phenolic compounds (phenol, bisphenol, etc.) described above. Terpene-phenolic resins such as α-pinene-phenolic resin, dipentene-phenolic resin, and terpene-bisphenolic resin; and aromatic modified terpene resins that are copolymers of various terpenes and aromatic monomers. Can be mentioned.

  Synthetic petroleum resins include, for example, homopolymers or copolymers of naphtha cracked oil (C5 fraction, C6 to C11 fraction, other olefinic fractions, etc.) and aliphatics that are hydrogenated products of these polymers. Examples include petroleum resins, aromatic petroleum resins, alicyclic petroleum resins, and aliphatic-alicyclic copolymer resins. Further, copolymers of the above various naphtha cracked oils and the above various terpenes, and copolymer petroleum resins that are hydrogenated products thereof are also included. Here, the C5 fraction of the naphtha cracked oil includes: isoprene; cyclopentadiene; 1,3-pentadiene; methylbutenes such as 2-methyl-1-butene and 2-methyl-2-butene; 1-pentene, 2-pentene Pentenes such as dicyclopentadiene are preferred, and the C6 to C11 fraction is indene; styrene; methyl such as o-vinyltoluene, m-vinyltoluene, p-vinyltoluene, α-methylstyrene, β-methylstyrene, etc. Styrenes; methylindene; ethylindene; vinylxylene; propenylbenzene and the like are preferable, and other olefinic fractions are preferably butene, hexene, heptene, octene, butadiene, octadiene and the like.

  Examples of the phenolic resin include alkylphenol resins, alkylphenol-acetylene resins obtained by condensation of alkylphenol and acetylene, and modified products thereof. Here, these phenolic resins may be either novolak resins obtained by methylolation of phenol with an acid catalyst or resol resins obtained by methylolation with an alkali catalyst.

  Examples of the xylene-based resin include a xylene-formaldehyde resin composed of m-xylene and formaldehyde, and a modified resin obtained by adding and reacting a third component thereto.

  Examples of the styrene resin include a low molecular weight product of polystyrene, a copolymer resin of α-methylstyrene and vinyltoluene, a copolymer resin of styrene, acrylonitrile, and indene.

  Examples of the isoprene-based resin include a resin obtained by copolymerizing a C10 alicyclic compound that is a dimerized product of isoprene and a C10 chain compound.

  Among the above tackifying resins, rosin resins, polyterpene resins, and synthetic petroleum resins are preferable, and those having an aliphatic and / or alicyclic structure are more preferable. Particularly preferred as petroleum resins having an aliphatic and / or alicyclic structure are partially and fully hydrogenated rosins and their derivatives for rosin resins, and homopolymers or copolymers of cyclic terpenes for polyterpene resins. Examples of coal and synthetic petroleum resins include aliphatic petroleum resins, alicyclic petroleum resins, aliphatic-alicyclic copolymer resins, and hydrogenated products of copolymers of naphtha cracked oil and various terpenes. Said tackifying resin is used individually or in mixture of 2 or more types.

  The content of the tackifying resin of the component (B) in the hot melt adhesive composition of the present invention is preferably 10 to 200 parts by weight with respect to 100 parts by weight in total of the component (A1) and the component (A2). Is 50 to 150 parts by weight. If the content of the component (B) tackifying resin is too small, the coatability and workability may be inferior, and if the content is too large, the flexibility may be inferior.

Examples of the component (C) wax used in the present invention include synthetic waxes such as polyethylene wax, polypropylene wax, and Fischer-Tropsch wax; and petroleum waxes such as paraffin wax and microwax.

  The content of the wax of the component (C) in the hot melt adhesive composition of the present invention is 10 to 100 parts by weight, preferably 15 with respect to 100 parts by weight of the total of the components (A1) and (A2). ~ 80 parts by weight. If the content of the component (C) wax is too small, the coatability and workability may be inferior, and if the content is too large, the low-temperature flexibility may be inferior.

  You may add an additive to the hot-melt-adhesive composition of this invention as needed. Examples of the additive include an antioxidant, a lubricant, an antistatic agent, a processability improving agent, and an antiblocking agent. Examples of the antioxidant include 2,6-di-tert-butyl-p-cresol (BHT), tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane. (Ciba Specialty Chemicals Co., Ltd., trade name: IRGANOX 1010), n-octadecyl-3- (4′-hydroxy-3,5′-di-tert-butylphenyl) propionate (Ciba Specialty Chemicals ( Co., Ltd., trade name: IRGANOX 1076), etc .; bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, tris (2,4-di-tert-butylphenyl) phos And phosphite stabilizers such as phite.

The hot melt adhesive composition of the present invention can be obtained by melt mixing. The mixing method is not particularly limited, and examples thereof include a known mixing method such as an extruder, an open roll mill, a Banbury mixer, a kneader, and a melt mixing tank. The melt mixing temperature is usually 100 to 250 ° C, preferably 140 to 200 ° C.

  The hot melt adhesive composition of the present invention is used for bonding various materials such as paper, wood, plastic, stone, and metal, and is particularly suitable for bonding paper and wood.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
The physical properties of the present invention were measured by the following method.
(1) Melt flow rate (MFR, unit: g / 10 minutes)
According to JIS K7210 (1995), the measurement was performed under the conditions of a load of 21.18 N and a temperature of 190 ° C.
(2) Repeating unit content derived from methyl methacrylate (unit: wt%)
FT / IR-7300 manufactured by JASCO Corporation was used as an apparatus, and it was determined from the following formula 1 based on an infrared absorption spectrum analysis method for a 0.3 mm thick sheet.
MMA = 4.1 × log (I ₀ /I)/t−5.3 Formula 1
Where MMA is the content (% by weight) of repeating units derived from methyl methacrylate, I is the transmitted light intensity at a frequency of 3448 cm ⁻¹ , I ₀ is the incident light intensity at a frequency of 3448 cm ⁻¹ , and t is the measurement Sample sheet thickness (cm) is shown. The baseline for determining I ₀ was 3510-3310 cm ⁻¹ .
(3) Density (Unit: kg / m ³ )
Using a sheet having a thickness of 1 mm obtained by press molding at 150 ° C., measurement was performed according to JIS K6760 (1981). However, the measurement was performed without annealing.
(4) Low temperature flexibility Using a 1 mm thick sheet obtained by press molding at 120 ° C., a test piece having a length of 150 mm and a width of 30 mm was cut out and left for 30 minutes in an incubator adjusted to 0 ° C. The presence or absence of cracks when bent 180 degrees was evaluated.
○: No cracking ×: Cracking occurred (5) Open time (adhesive time, unit: seconds)
A 1 mm thick sheet obtained by press molding at 120 ° C. was cut into a size of 150 mm in length and 10 mm in width to obtain a test piece, which was melted on a hot plate at 150 ° C.
Prepare two pieces of maple wood, and change the standing time from the time of scraping the melted test piece on one end face to the time of attaching it to the end face of the other piece of wood. When the hand was released from the lower piece of wood immediately after the pasting, the maximum time for which the lower piece of wood did not fall was defined as the open time (adhesive time).

Example 1
Production of (Component A1) 5 mol% of methyl methacrylate as another raw material, 11 mol% of propane as a chain transfer agent, and 1000 ppm by weight of organic peroxide as a radical generator were added to ethylene.
This mixture was continuously fed to a tank-type continuous reactor, and ethylene and methyl methacrylate were copolymerized under the polymerization conditions of a reaction pressure of 186 MPa and a reaction temperature of 185 ° C. to form an ethylene-methyl methacrylate copolymer (component A1) was obtained.
In the obtained (A1) ethylene-methyl methacrylate copolymer, the content of repeating units derived from methyl methacrylate was 30% by weight, and the melt flow rate was 1050 g / 10 min.
Production of (Component A2) Ethylene and butene-1 were continuously fed to a tank-type continuous reactor so that the proportion of butene-1 was 41 mol% (the sum of both was 100 mol%). In the presence of a metallocene catalyst, ethylene and butene-1 were copolymerized under polymerization conditions of a reaction pressure of 78 MPa and a reaction temperature of 232 ° C. to obtain an ethylene-butene-1 copolymer (component A2).
As the metallocene catalyst, 1 mol part of dimethylsilylene (tetramethylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dimethoxide, 50 mol part of triisobutylaluminum, N, N-dimethylaniline A catalyst obtained from 6 mole parts of nium (pentafluorophenyl) borate was used.
The melt flow rate of the obtained (A2) ethylene-butene-1 copolymer was 650 g / 10 min, and the density was 877 kg / m ³ .
100 parts by weight of a mixture of 50% by weight of ethylene-methyl methacrylate copolymer as component (A1) and 50% by weight of ethylene-butene-1 copolymer as component (A2), Arakawa Chemical Industries, Ltd. as component (B) 100 parts by weight of Chinese rosin WW manufactured by Nihon Seisaku Co., Ltd. and 22 parts by weight of paraffin wax (softening point 68 ° C.) as component (C) were melted and mixed at 150 ° C. to obtain a resin composition. . The evaluation results of the obtained resin composition are shown in Table 1.

Comparative Example 1
100 parts by weight of ethylene-methyl methacrylate copolymer as component (A1), 100 parts by weight of Chinese rosin WW manufactured by Arakawa Chemical Co., Ltd. as component (B), and paraffin manufactured by Nippon Seiki Co., Ltd. as component (C) 22 parts by weight of wax (softening point 68 ° C.) was melted and mixed at 150 ° C. to obtain a resin composition. The evaluation results of the obtained resin composition are shown in Table 1.

Comparative Example 2
100 parts by weight of ethylene-butene-1 copolymer as component (A2), 100 parts by weight of Chinese rosin WW manufactured by Arakawa Chemical Industries, Ltd. as component (B), and paraffin manufactured by Nippon Seiki Co., Ltd. as component (C) 22 parts by weight of wax (softening point 68 ° C.) was melted and mixed at 150 ° C. to obtain a resin composition. The evaluation results of the obtained resin composition are shown in Table 1.

As described above, according to the present invention, a hot melt adhesive composition having excellent low-temperature flexibility and a long open time (adhesive time) can be provided. In addition, the hot melt adhesive composition of the present invention is used for hot melts such as bookbinding, box making / sealing of cardboard / carton cases, assembly of packaging containers, production of building materials such as plywood, and assembly of parts such as electronic parts / sanitary products. It is suitably used as an adhesive.

Claims (1)

A hot melt adhesive composition containing the following component (A1), component (A2), component (B) and component (C), wherein the total of component (A1) and component (A2) is 100% by weight When the content of the component (A1) is 1 to 99% by weight, the content of the component (A2) is 99 to 1% by weight, and the total amount of the components (A1) and (A2) is 100 parts by weight. The hot melt adhesive composition has a content of component (B) of 10 to 200 parts by weight and a content of component (C) of 10 to 100 parts by weight.
Component (A1): When the total amount of component (A1) is 100% by weight, the content of repeating units derived from ethylene is 85 to 50% by weight, and the content of repeating units derived from unsaturated carboxylic acid esters Ethylene-unsaturated carboxylic acid ester copolymer component (A2) having an amount of 15 to 50% by weight and a melt flow rate of 150 to 3000 g / 10 min: ethylene-α produced using a metallocene catalyst An ethylene-α-olefin copolymer component (B) having a melt flow rate of 50 to 2000 g / 10 min and a density of 860 to 930 kg / m ³ : tackifying resin component ( C): Wax