JP3292659B2 - Resin composition and hot melt adhesive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a resin composition and a hot melt adhesive. More specifically, a resin composition excellent in low-temperature adhesiveness and high-temperature adhesiveness to various materials, and particularly suitable for bonding difficult-to-adhesive materials such as polyolefin molded articles made of the composition, and having a set time. For short hot melt adhesives.

[0002]

2. Description of the Related Art Conventionally, resin compositions and hot-melt adhesives used for bonding polyolefin-based films, nonwoven fabrics, resin molded products, and the like include modified polyolefins obtained by graft copolymerizing styrene with crystalline polyolefin ( For example, Japanese Unexamined Patent Publication No. 1-49187), those obtained by graft-polymerizing styrene to a low melt viscosity amorphous polyolefin (for example, JP-A-7-3)
No. 16523) is known.

[0003]

However, when the above-mentioned materials are used as a hot melt adhesive, the low-temperature adhesiveness is insufficient, and the above-mentioned materials have insufficient high-temperature adhesiveness and set time.

[0004]

Means for Solving the Problems The present inventors have solved these problems, have good low-temperature adhesiveness and high-temperature adhesiveness, and can be used for adhesion of polyolefin resin molded articles and the like. As a result of intensive studies for the purpose of obtaining a hot melt adhesive, it has been found that a mixture of a polyolefin wax and a graft modified product of a specific polyolefin resin with a vinyl monomer has a dramatic improvement in performance. Reached. That is, the present invention provides an ethylene-butene copolymer, an ethylene-propylene copolymer, an ethylene-vinyl acetate copolymer and an ethylene-propylene non-conjugated diene terpolymer which is at least one selected from the group consisting of terpolymers. Resin composition comprising a graft-modified product (A) obtained by polymerizing a radical monomer (a2) in a heat-melt kneader in the presence of a copolymer (a1) and a thermally degraded low-molecular-weight olefin (B) ;
And a hot melt adhesive comprising the resin composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As the polyolefin polymer (a1) in the present invention, an ethylene-butene copolymer,
Examples include an ethylene-propylene copolymer, an ethylene-vinyl acetate copolymer, an ethylene-propylene non-conjugated diene terpolymer, an α-olefin homopolymer, and an ethylene-α-olefin copolymer. Among these, preferred are ethylene-butene copolymer, ethylene-propylene copolymer, ethylene-α-olefin copolymer and α-olefin homopolymer, more preferably ethylene-propylene copolymer, ethylene-α-olefin It is a copolymer. The number average molecular weight of (a1) is usually from 1000 to 1
00000, and preferably 2000 to 50,000.

The radical polymerizable monomer (a2) used for the graft modification in the present invention includes a styrene compound, a vinyl group-containing carboxylic acid or a derivative thereof,
(Meth) acrylonitrile, ethylidene norbornene,
Dicyclopentadiene and the like.

Specific examples of the styrene compound include styrene, t-butylstyrene, α-methylstyrene, and p-methylstyrene.
-Methylstyrene, chlorostyrene, bromostyrene,
Examples include fluorostyrene, ethylstyrene, divinylbenzene, N, N-diethylaminostyrene, and the like.
Particularly preferred among these is styrene.

[0008] The vinyl group-containing carboxylic acids or derivatives thereof include vinyl group-containing carboxylic acids [for example,
(Meth) acrylic acid, (anhydride) maleic acid, fumaric acid, itaconic acid and the like]; (meth) acrylic acid ester [alkyl having 1 to 18 carbon atoms (methyl, ethyl, propyl,
Octyl, dodecyl, etc.) (meth) acrylate, C6-C12 alicyclic alkyl (cyclohexyl, dicyclohexyl, etc.) (meth) acrylate, C7-C21 aralkyl (benzyl, etc.) (meth) acrylate, hydroxyalkyl ( (C2-6) (meth) acrylate, glycidyl (meth) acrylate, etc.]; maleic ester [C1-18 alkyl ester]; fumaric ester [C1-18 alkyl ester]; vinyl group-containing Imidized dicarboxylic acid [maleimide, N-methylmaleimide, N-butylmaleimide,
N-phenylmaleimide and the like]. Of these, preferred are (meth) acrylic acid, maleic anhydride, (meth) acrylic acid ester and maleic acid ester.

In the present invention, the weight ratio of (a1) :( a2) is usually 100: (1 to 10) from the viewpoint of adhesive strength and workability when used as a hot melt adhesive.
0), preferably 100: (3 to 80), more preferably 100: (5 to 50).

The above thermally degraded low molecular weight polyolefin (B)
The production method is not particularly limited as long as it can be obtained by thermally degrading a polyolefin. Examples of these polyolefins include homopolymers of α-olefins selected from the group consisting of ethylene, propylene, 1-butene, and 4-methyl-1-pentene, and copolymers of two or more of these α-olefins. No.
Of these, particularly preferred are polypropylene and polyethylene. The number average molecular weight of (B) is usually from 70 to 40,000, preferably from 100 to 10,000 from the viewpoint of adhesiveness and dispersed particle size.

In the present invention, the SP values of (A) and (B) and (B) and (C) are set so that the dispersed particle size of the thermally degraded low molecular weight polyolefin (B) is 1 micrometer or less. Solubility parameter) should be 1 or less, preferably 0.8 or less. The SP value is Fed
ors method [Polym. Eng. Sci. 14 (2) 1
52, (1974)].

In the present invention, the modified graft (A):
The weight ratio of the thermally degraded low-molecular-weight polyolefin (B) is usually 10 from the viewpoint of workability, low-temperature adhesion and high-temperature adhesion.
0: (1 to 100), preferably 100: (10 to 9)
0), more preferably 100: (20-60).

[0013] The resin composition of the present invention has wettability, adhesion,
From the viewpoint of cohesive force, the elastic modulus is 10 ⁷ to 10 ¹⁰ dyne / c.
m.

In order to obtain the above elastic modulus in the range of -30 ° C. to 60 ° C., the elastic modulus of the graft-modified product (A) at -30 ° C. is set to 10 ¹⁰ dyne / cm or less, and the heat-degraded low molecular weight polyolefin is used. It is necessary to disperse (B) by 1 micrometer or less.

In the present invention, a tackifier (C) can be contained for the purpose of further improving the adhesiveness. In the step of adding (C), part or all of (C) is added to (a1) in advance and graft-modified;
Addition of (C) to the modified graft (A), and the like. Of these, the following method is preferred.

Examples of the tackifier (C) include terpene resins or derivatives thereof (for example, terpene-styrene copolymer resins, terpene phenol copolymer resins), and aliphatic hydrocarbon resins (1,3 pentadiene, dicyclopentadiene). Pentadiene, etc.), aromatic hydrocarbon resins or copolymer resins thereof, rosin derivatives (eg, esterified or maleated abietic acid type rosin derivatives) and the like. Among these, aliphatic hydrocarbon resins and aromatic hydrocarbon resins are preferable in terms of compatibility. More preferably, it is an aliphatic hydrocarbon resin.

In the present invention, the weight ratio of the graft-modified product (A) to the tackifier (C) is usually 100: (0 to 250), preferably 100: (20), from the viewpoint of low-temperature adhesion and high-temperature adhesion. ~ 200), more preferably 100:
(40 to 150). If it exceeds 250, the low-temperature adhesive property and the high-temperature adhesive property are hindered.

The method for producing the resin composition of the present invention is not particularly limited. For example, a resin (A) obtained by graft-polymerizing (a2) in the presence of (a1) may be used.
A method of mixing (B) and (C); (a1) and (B)
(A2) is polymerized in the presence of (a2) and then mixed with (C); in the presence of (a1), (B) and (C), (a)
A method of polymerizing 2) and the like can be mentioned. Of these, the methods (1) and (2) are preferable, and the method (1) is more preferable.

A known polymerization initiator can be used for the graft polymerization, if necessary. As the polymerization initiator, ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, organic peroxides such as peroxydicarbonate and azo compounds such as azoisobutyronitrile and the like. Two or more of them may be used in combination. As the polymerization initiator, one which is easily soluble in the radical polymerizable monomer (a2) is appropriately selected and used. The amount of the polymerization initiator is (a2) 1
It is usually 0.05 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on 00 parts by weight. The graft polymerization reaction is usually performed without a solvent, but an organic solvent may be used if necessary. Examples of the organic solvent include an alicyclic hydrocarbon solvent, an aromatic hydrocarbon solvent, an alcohol solvent, a halogen solvent, a ketone solvent, and an ether solvent.

The temperature of the graft polymerization is not particularly limited and may be any temperature at which the monomer can be substantially polymerized, but is preferably a temperature at which the half-life of the polymerization initiator is less than 1 minute, usually 8
The temperature is 0 to 260 ° C, preferably 120 to 220 ° C.
The time of the graft polymerization is not particularly limited, but is usually 5 minutes.
〜60 minutes, preferably 10-50 minutes.

The type and shape of the heat-melt kneader used for the graft polymerization are not particularly limited, and include, for example, a plastomill, a kneader, a screw having a highly compressible shape having a reverse thread, or a stirrer. A mixing machine, a Kolben, etc. can be mentioned.

When the resin composition of the present invention is used as a hot-melt adhesive, various known additives [antioxidants, fillers, liquid plasticizers, pigments, etc.] are used as long as the effects of the present invention are not impaired. Wax, lubricant, etc.] can be added. Examples of the hot melt adhesive include various resins such as a polyolefin resin and an ABS resin, and various materials such as a metal. Particularly, the hot melt adhesive is suitable for a polyolefin resin such as polypropylene, which has poor adhesion.

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples. In addition, the part in an Example shows a weight part and% shows weight%. The reactions of the following Examples 1 to 3 were carried out in a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) under constant stirring at 60 rpm.
This was performed under a nitrogen flow of 0 ml / min.

[0024]

【Example】

Example 1 Ethylene-α-olefin copolymer (“APA2535” manufactured by Ube Lexen Co., ethylene content 14 wt%) 23
Parts and 7 parts of ethylene-propylene copolymer rubber (“EPR912P” manufactured by Nippon Synthetic Rubber Co., Ltd.) were completely melted at 100 ° C. for 30 minutes. Add "Perbutyl Z" (tert-butyl peroxybenzoate, manufactured by NOF Corporation)
5 parts of a styrene monomer containing 0.025 parts was added, the temperature was raised to 160 ° C., and the mixture was reacted for 30 minutes. 15 parts of thermally degraded low molecular weight polypropylene (“Viscol 660P” manufactured by Sanyo Chemical Co., Ltd.) and aliphatic petroleum hydrogenated resin (“Escolets 5300HC” manufactured by Tonex Corporation)
0 parts were added and melt-mixed at 160 ° C. for 30 minutes to obtain an adhesive composition. The resulting adhesive composition was demonomerized in a vacuum constant-temperature dryer (ADVANTEC) at 5 mmHg and 180 ° C. for 2 hours to obtain a hot melt adhesive composition of the present invention.

Examples 2 to 3 The hot melt adhesive compositions of the present invention were obtained according to the formulations shown in Table 1 in the same manner as in Example 1.

[0026]

[Table 1]

(Explanation of symbols) APA; α-polyolefin (melt viscosity at 190 ° C. 35
00cP, "UT2535" manufactured by Ube Lexen) EPR; ethylene-propylene copolymer rubber (propylene content: 22 wt%, "EP912P" manufactured by Nippon Synthetic Rubber Co., Ltd.) ST; styrene bisco; thermally degraded low molecular weight polypropylene (melting point: 145)
PWAX; paraffin wax (melting point 69 ° C., “PW155” manufactured by Nippon Seiwa Co., Ltd.) Esco; tackifier (DCPD petroleum resin having a softening point of 100 ° C., manufactured by Tonex Corporation) Escolets 5300H
C])

Comparative Example 1 Ethylene-α-olefin copolymer “APA2535”
50 parts and tackifier "ESCOLETZ 5300HC" 5
0 parts were mixed and used.

Comparative Example 2 A commercially available hot-melt adhesive for PP-coated paper (main component is a modified olefin) was used as it was.

Performance Test Examples Melt viscosity, OPP adhesive strength (low temperature, normal temperature, high temperature), PET adhesive strength of the hot melt adhesives obtained in Examples 1 to 3 and Comparative Examples 1 to 2 according to the following measuring methods, respectively. , PP adhesive shear strength, PMMA adhesive shear strength, and set time were measured. The results are shown in Tables 2 and 3.

[0031]

[Table 2]

[0032]

[Table 3] (Measurement method) Melt viscosity; Viscosity at 180 ° C. using a B-type viscometer Peel strength; Preparation of test pieces; Each adhesive was 25 mm × 25 mm, thickness 2
00 μm, biaxially oriented polypropylene film (OP
P), and a polypropylene film was pressed under the conditions of 100 ° C. × 1 minute × 1 kg / cm ² and left for 24 hours. Measurement: T-type peeling, 23 ° C, 50R. H. 3 in the environment
The maximum load at the time of breaking at a shear rate of 00 mm / min was measured and indicated by an average value of five pieces. Set time: 18 hours for PET film
Beat shape at 0 ° C, application amount 0.1g / m, press pressure 2kg
/ Cm ² , the minimum time to develop 80% or more of the maximum value of the adhesive peel strength. Shear strength; preparation of test pieces; each adhesive 25 mm x 25 mm, thickness 1
mm, applied to PP at 180 ° C., hand-pressed after 10 seconds, and left for 24 hours. Measurement; shear, 23 ° C, 50R. H. 50 in the environment
The maximum load at the time of breaking at a shear rate of mm / min was measured and indicated by an average value of five pieces.

[0033]

The resin composition of the present invention has the following effects. (1) It has excellent low-temperature and high-temperature adhesive properties and can be used in a wide temperature range. (2) It has particularly good initial adhesive strength (short set time). (3) It shows excellent adhesion to various materials. In particular, it shows excellent adhesion to polyolefin resins such as polypropylene, which are difficult to adhere to. (4) It has excellent workability due to its low viscosity. Due to the above effects, the hot melt adhesive comprising the resin composition of the present invention can be used for packaging materials such as polypropylene molded articles, polypropylene laminated paper and corrugated cardboard, which are difficult adhesives, and has a low viscosity and Since it has a short set time, it can be used in a wide variety of applications, such as bonding in high-speed lines, and is extremely useful industrially.

Claims (5)

(57) [Claims] 1. An ethylene-butene copolymer, ethylene-
Radical polymerizable monomer in the presence of at least one polyolefin-based polymer (a1) selected from the group consisting of propylene copolymer, ethylene-vinyl acetate copolymer and ethylene-propylene non-conjugated diene terpolymer A resin composition comprising a graft-modified product (A) obtained by polymerizing the product (a2) in a heat-melt kneader and a thermally degraded low-molecular-weight olefin (B). 2. The weight ratio of (A) :( B) is 100: (1).
The resin composition according to claim 1, wherein the difference in SP value between (A) and (B) is 1 or less. 3. The composition further comprises a tackifier (C).
The resin composition according to claim 1, wherein the weight ratio of (A) :( C) is 100: (20 to 250). 4. The resin composition according to claim 1, which has an elastic modulus of 10 ⁷ to 10 ¹⁰ dyn / cm. 5. A hot melt adhesive comprising the resin composition according to claim 1.