JPH0782328A - Compound resin composition and hot melt adhesive - Google Patents

Abstract

PURPOSE:To obtain a compound resin composition excellent in resin properties, heat stability and adhesiveness by mixing an amorphous ethylene copolymer with a lowly viscous resin and a radical-polymerizable monomer in a specified ratio and subjecting the resulting mixture to a polymerization reaction in a melt kneader. CONSTITUTION:50-1000 pts.wt. at least one radical-polymerizable monomer selected from among a styrene compound, a vinyl carboxylic acid or a derivative thereof and (meth)acrylonitrile is polymerized in the presence of 100 pts.wt. amorphous ethylene copolymer (e.g. ethylene/alpha-olefin copolymer) having a melt index of below 50 and a degree of crystallinity of below 10 and a 30-300 pts.wt. lowly viscous resin (e.g. propylene resin) of a melt index of 50 or above in a melt kneader. This polymerization is carried out at 80-260 deg.C in the presence of optionally known polymerization initiator (e.g. ketone peroxide) and an organic solvent (e.g. alicyclic hydrocarbon solvent).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composite resin composition and an adhesive. More specifically, it relates to a composite resin composition having excellent processability, adhesiveness, thermal stability, and flexibility, and a hot melt adhesive containing the same.

[0002]

2. Description of the Related Art Conventionally, as an adhesive used for adhering various films such as polyolefin films and resin molded products, for example, an adhesive composed of a modified polyolefin obtained by graft-copolymerizing styrene with a crystalline polyolefin (for example, Japanese Patent Publication No. No. 49187), a modified product obtained by grafting a hydrogenated product of a styrene-butadiene block copolymer with a polar group-containing compound such as maleic acid (for example, JP-A-58).
-19376, etc.), blends of graft block copolymers of polyolefin and polystyrene (for example, JP-A-3-7746, etc.) and the like.

[0003]

However, an adhesive composed of a modified polyolefin obtained by graft-copolymerizing styrene with a crystalline polyolefin has problems such as a short open time when used as a hot melt adhesive.
Further, a modified product obtained by grafting a polar group-containing compound onto a hydrogenated product of a styrene-butadiene block copolymer has a low modification rate and thus has a problem in terms of adhesiveness. Further, in the case of a blend of a graft block copolymer of polyolefin and polystyrene, when it is used as a hot melt, there is a problem of phase separation due to thermal aging.

[0004]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve these problems and improve processability, adhesiveness and thermal stability. We have found that the performance is dramatically improved by grafting both of the viscous resins with a styrene compound or the like, and reached the present invention. That is, the present invention is
100 parts by weight of an amorphous ethylene copolymer (A) having a melt index of less than 50 and a crystallinity of less than 10% by the D1238-E method and ASTM D1238-E
At least 1 selected from the group consisting of styrene compounds, vinyl group-containing carboxylic acids or their derivatives, and (meth) acrylonitrile in the presence of 30 to 300 parts by weight of a low-viscosity resin (B) having a melt index of 50 or more by the method. 50-1 radical-polymerizable monomer (C)
A composite resin composition obtained by polymerizing 000 parts by weight in a heating melt kneader; and a hot melt adhesive containing the same.

Specific examples of the amorphous ethylene copolymer (A) in the present invention include ethylene and one or more other vinyl compounds [eg α-olefin (propylene, 1-
Butene, 4-methyl-1-pentene, etc.), vinyl acetate,
[Methacrylic acid, acrylic acid, etc.], graft modified products of these vinyl group-containing carboxylic acids, and blends of two or more of these copolymers or modified products. Among these, preferable ones are ethylene-α-olefin copolymers and ethylene-α-olefin-non-conjugated diene copolymers, and more preferable ones are ethylene-propylene copolymers, ethylene-propylene-dicyclopentadiene copolymers and It is an ethylene-propylene-ethylidene norbornene copolymer.

The crystallinity of (A) is usually less than 10%, preferably less than 7%. When the crystallinity of (A) is 10% or more, sufficient flexibility cannot be obtained when it is used as a composite resin composition, and sufficient open time cannot be obtained when it is used as a hot melt adhesive.

(A) ASTM D1238-E method (1
The melt index according to 90 ° C., 2160 g) is usually less than 50, preferably less than 40. When the melt index of (A) is 50 or more, sufficient strength of the composite resin cannot be obtained.

As the low-viscosity resin (B), a propylene copolymer (low molecular weight polypropylene, amorphous propylene-
Ethylene copolymer, etc.), ethylene copolymer (ethylene-
Vinyl acetate copolymer, etc.), hydrogenated petroleum resin (eg,
Hydrogenated products such as C9-based petroleum resins, C5-based petroleum resins, dicyclopentadiene-based petroleum resins), hydrogenated terpene resins and hydrogenated rosin resins, and graft-modified products thereof with vinyl group-containing carboxylic acids Can be mentioned.

The melt index (B) according to the ASTM D1238-E method is usually 50 or more, preferably 1
It is 00 or more. When the melt index of (B) is less than 50, the composite resin composition obtained by polymerization in the melt mixer has high viscosity, and the coatability as a hot melt adhesive is deteriorated.

Examples of the radically polymerizable monomer (C) in the present invention include styrene compounds, vinyl group-containing carboxylic acids or their derivatives, and (meth) acrylonitrile.

Styrene compounds include styrene and t
-Butylstyrene, α-methylstyrene, p-methylstyrene, chlorostyrene, bromstyrene, fluorostyrene, ethylstyrene, divinylbenzene, N, N-diethylaminostyrene and the like can be mentioned. Of these, styrene is particularly preferable. .

The vinyl group-containing carboxylic acids or derivatives thereof include vinyl group-containing carboxylic acids [(meth) acrylic acid, maleic anhydride, fumaric acid, itaconic acid, etc.], (meth) acrylic acid esters [eg, having 1 carbon atom.
~ 18 alkyl (methyl, ethyl, propyl, octyl, dodecyl, etc.)-, C6-12 alicyclic alkyl (cyclohexyl, dicyclohexyl, etc.)-, C7-21 aralkyl (e.g., benzyl)-, hydroxy (Meth) acrylates such as alkyl (having 2 to 6 carbon atoms)-and glycidyl-], imidized products of vinyl group-containing dicarboxylic acid [maleimide, N-methylmaleimide, N-
Butyl maleimide, N-phenyl maleimide, etc.] and the like. Of these, preferred are (meth) acrylic acid, maleic anhydride and their esterified products.

In the present invention, the weight ratio of (A), (B) and (C) is usually (A) :( B) :( C).
It is 0: (30-300) :( 50-1000), preferably 100: (50-200) :( 70-500). If the ratio of (B) is less than 30, the resulting composite resin will have a high viscosity and the workability when used as a hot melt adhesive will be poor, and if it exceeds 300, the rubber elasticity of the composite resin composition will decrease. Further, if the ratio of (C) is less than 50, the modification effect on (A) and (B) is poor and the dispersion system is not stable, so the thermal stability when used as a hot melt adhesive becomes insufficient, and exceeds 1000. And the rubber elasticity of the composite resin composition decreases.

The method for producing the composition of the present invention is not particularly limited, but for example, one prepared by previously polymerizing (C) in the presence of (A) and one prepared by polymerizing (C) in the presence of (B). A method of polymerizing (C) in the presence of (B) and a method of polymerizing (C) in the presence of (A),
A method of polymerizing (C) in the presence of (A), a method of polymerizing (C) in the presence of (B), a method of polymerizing (C) in the presence of (A) and (B), etc. Can be mentioned. Of these, the method is preferred.

For the polymerization, known polymerization initiators and organic solvents can be used if necessary. As the polymerization initiator,
Examples thereof include organic peroxides such as ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, and peroxydicarbonate, and azo compounds such as azoisobutyronitrile. As the organic solvent, an alicyclic hydrocarbon solvent,
Examples thereof include aromatic hydrocarbon solvents, alcohol solvents, halogen solvents, ketone solvents, ether solvents and the like.

The polymerization temperature is not particularly limited and may be a temperature at which the monomers are substantially polymerized, but it is usually 80 to 26.
It is 0 ° C.

The heating and melting mixer used for the production is not particularly limited in its mode, shape, etc. For example, a mixer having a highly compressible screw having a reverse screw portion or a ribbon-shaped stirring blade, A kneader or the like can be used.

When the composition of the present invention is used as a hot melt adhesive, various known additives such as adhesion promoters (rosin derivatives, terpene resins, hydrocarbon resins, etc.), waxes (paraffin wax, micro wax) are used. Crystallin wax, low molecular weight polyolefin wax, etc.), antioxidant, filler, plasticizer, etc.] may be added.

[0019]

The present invention will be further described with reference to the following examples, but the present invention is not limited thereto. In the following, “part” means part by weight.

Examples 1 to 8 and Comparative Examples 1 and 2 A composite resin of the present invention and a comparative resin were produced using a ventilated twin-screw extruder with a vent having a screw having a diameter of 45 mm and L / D = 50. . This extruder has a four-divided barrel whose temperature can be adjusted separately, and a raw material supply port is provided in front of the first barrel and a vent port is provided in front of the fourth barrel. The screw of the portion corresponding to the third barrel portion is a reverse screw, and the pitch of the screw near the vent port is 30 mm. The extruder has one barrel 1
45 ° C, 160 ° C for the second barrel, 190 for the third barrel
℃, keep the fourth barrel at 230 ℃, vent port 20 Tor
The pressure was reduced to r and the resin mixture dispersed in the ratio shown in Table 1 was supplied to the extruder from the raw material supply port, and the monomer was supplied to the extruder from the side supply port attached to the first barrel while keeping the residence time for 7 minutes. Polymerization was performed to obtain a composite resin composition.

[0021]

[Table 1] (Explanation of symbols and the like) AA; acrylic acid MA; maleic anhydride ACN; acrylonitrile DCP; dicumyl peroxide EPR; ethylene propylene copolymer (crystallinity 6%,
Melt Index 2, made from Japan Synthetic Rubber "EP912
P ") EPDM; ethylene propylene ethylidene norbornene copolymer (crystallinity 5%, melt index 0.8,
Japanese synthetic rubber "EP57P") APAO: Amorphous polypropylene (melt index 100 or more, Ube Lexen "UT2535") PP1; Maleic anhydride modified low molecular weight polypropylene (melt index 100 or more, Sanyo Kasei "Umex 1001") Hydrogenated resin; Hydrogenated terpene resin (melt index 1
00 or more, "Clearon P105" manufactured by Yasuhara Chemical Co., Ltd. PE: Crystalline high density polyethylene (melt index 8) SEBS; Hydrogenated styrene butadiene block copolymer (melt index 1 or less)

The composite resin composition thus obtained was molded by an injection molding machine to prepare a test piece. Table 2 shows the resin physical property values measured using the test pieces.

[0023]

[Table 2] (Measuring method) Breaking strength; JIS K6301 (unit: kgf / c
m ² ) Elongation at break; JIS K6301 (unit:%) Hardness; JIS K6301 (JIS A) MFR (melt index); ASTM D1238-L method (230 ° C., 2160 g)

100 parts of each composite resin obtained, 300 parts of tackifier (“Admap P100” manufactured by Idemitsu Petrochemical: hydrogenated petroleum resin having a softening point of 100 ° C.), and process oil (“Diana Process PW90” manufactured by Idemitsu Kosan) 50 Parts and antioxidants (“Irganox 10” manufactured by Ciba Geigy
10 ") 2.5 parts were melt mixed to obtain a hot melt adhesive. Table 3 shows the performance measurement results of the obtained adhesive.

[0025]

[Table 3] (Measuring method) Shear adhesive strength: The peeling adhesive strength of an aluminum plate / polyester film was measured based on JIS K6854 (unit: kgf / cm ² ). Peel strength: The 180 ° peel strength on an aluminum plate / polyester film was measured based on JIS K6854 (unit: g / 25 mm). Thermal stability: Evaluated by the rate of change in viscosity by a B-type viscometer after standing in an inert gas atmosphere at 190 ° C. for 5 hours (◯: rate of change less than 20%, ×: rate of change 20% or more).

[0026]

The composite resin composition of the present invention has the following effects. (1) Since both the low melt viscosity resin and the polyethylene copolymer having low crystallinity are graft-modified with a radical polymerizable monomer, the resin has excellent physical properties. (2) Since the phase separation does not occur even if the molten state is maintained for a long time, the thermal stability is extremely good. (3) Excellent adhesion to various materials. Because of the above effects, the composite resin composition of the present invention is particularly useful as a hot-melt adhesive or pressure-sensitive adhesive, and can also be used in the form of an organic solvent solution, emulsion, dispersion, film or sheet.
The composite resin composition of the present invention can also be used as a modifier for the mechanical properties of molding resins such as polystyrene and rubber and as an agent for improving the cold resistance of asphalt.

Claims (5)

[Claims] 1. Amorphous ethylene copolymer (A) having a melt index of less than 50 and a crystallinity of less than 10% according to the ASTM D1238-E method and 100 parts by weight of A.
From the group consisting of styrene compounds, vinyl group-containing carboxylic acids or their derivatives and (meth) acrylonitrile in the presence of 30 to 300 parts by weight of a low viscosity resin (B) having a melt index of 50 or more according to STM D1238-E method. A composite resin composition obtained by polymerizing 50 to 1000 parts by weight of at least one selected radically polymerizable monomer (C) in a heating and melting kneader. 2. The composition according to claim 1, wherein (A) is an ethylene-α-olefin copolymer and / or an ethylene-α-olefin-non-conjugated diene copolymer. 3. (B) is at least one low viscosity resin selected from the group consisting of propylene copolymer, ethylene copolymer, hydrogenated petroleum resin, hydrogenated terpene resin and hydrogenated rosin resin. Item 3. The composite resin composition according to Item 1 or 2. 4. The composite resin composition according to claim 1, wherein (B) is a low-viscosity resin of an amorphous polypropylene copolymer and / or an ethylene-vinyl acetate copolymer. 5. A hot melt adhesive containing the composite resin composition according to claim 1.