JP3032881B2 - Composite resin composition and hot melt adhesive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composite resin composition and a hot melt adhesive. More specifically, the present invention relates to a composite resin composition having excellent heat creep properties, adhesive properties, oil retaining properties and the like, and a hot melt adhesive comprising the same, particularly suitable for bonding a polyolefin molded article.

[0002]

2. Description of the Related Art Conventionally, as a hot-melt adhesive used for bonding a polyolefin-based film, nonwoven fabric, resin molded product, etc., a modified polyolefin obtained by graft copolymerizing styrene with a crystalline polyolefin (for example, Japanese Patent Publication No. No. 49187) is known. The applicant of the present invention has previously filed an application consisting of a product obtained by grafting styrene in the presence of an ethylene / propylene copolymer and a low molecular weight polyolefin resin (Japanese Patent Application No. 6-2).
02704).

[0003]

However, there is a problem that the above-mentioned materials have a short open time when used as a hot-melt adhesive and bleed out when oil or the like is added in order to improve this. Further, although the open time is maintained, there is a problem that the heat creep resistance is not always sufficient.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have intensively studied to solve these problems and to obtain a hot melt adhesive having good heat creep resistance and oil retention. By using a composite resin obtained by graft-modifying a styrene compound or the like in the presence of a homopolymer and / or an ethylene-α-olefin copolymer and a specific low-viscosity polyolefin resin, the performance is dramatically improved. This has led to the present invention. That is, the present invention relates to an α-olefin homopolymer (A1) having a melt index of 1 to 100 according to the ASTM D1238-L method and / or an ethylene / α-olefin copolymer having a melt index of more than 10 and 100 or less according to the same method. Α-olefin-based (co) polymer (A) composed of the polymer (A2) and a low-molecular-weight polypropylene-based (co) polymer obtained by a thermal degradation method and a polypropylene-based polymer having a crystallinity of 10% or less obtained by a polymerization method ( A melt viscosity at 190 ° C. of 30 to 100,000
In the presence of a low viscosity polyolefin resin (B) of cP,
(A) polymerizing at least one radical polymerizable monomer (C) selected from the group consisting of a styrene-based compound, a vinyl group-containing carboxylic acid or a derivative thereof, and (meth) acrylonitrile in a hot melt kneader; ):
The weight ratio of (B) :( C) is 100: (30-300):
(1-50) a composite resin composition; and a hot melt adhesive comprising the composition.

Specific examples of the α-olefin homopolymer (A1) constituting (A) in the present invention include homopolymers such as propylene, 1-butene, 1-pentene and 4-methyl-1-pentene. Can be Specific examples of the ethylene / α-olefin copolymer (A2) include a copolymer of ethylene and the above-mentioned α-olefin.

Specific examples of the α-olefin (co) polymer (A) include the above (A1) and (A2) and graft-modified products of these (co) polymers with vinyl group-containing carboxylic acids, A blend of two or more (co) polymers or modified products may be used. Preferred among these are butene-1 homopolymer and ethylene / butene-1 copolymer.

The melt index of (A1) by the ASTM D1238-L method (230 ° C., 2160 g) is usually 1 to 100, preferably 5 to 50. (A1)
If the melt index exceeds 100, the oil resistance becomes insufficient, and if it is less than 1, sufficient workability cannot be obtained.

The melt index of (A2) according to the ASTM D1238-L method (230 ° C., 2160 g) is usually from 10 to 100, preferably from 10 to 50. (A2) has a melt index of 10
If it exceeds 0, the oil resistance becomes insufficient, and if it is 10 or less, sufficient workability cannot be obtained.

As the low-viscosity polyolefin-based resin (B), low-molecular-weight polypropylene-based resin (co) obtained by thermal degradation
Use of the polymer in combination with a polypropylene (co) polymer having a crystallinity of 10% or less obtained by a known polymerization method and these vinyl group-containing carboxylic acids [(meth) acrylic acid, (anhydride) maleic acid, fumaric acid , Itaconic acid, etc.]. The propylene unit content in (B) is usually at least 30% by weight, preferably at least 50% by weight. (B) the propylene content is 3
If the amount is less than 0% by weight, the heat resistance of the composite resin composition decreases.

The melt viscosity at 190 ° C. of (B) is usually 3
0 to 100,000 cP, preferably 40 to 20,000 cP
0 cP. If the melt viscosity is less than 30 cP, the strength of the composite resin composition will be insufficient, and if it exceeds 100,000 cP, the resulting composite resin composition will have a high viscosity, resulting in reduced processability and coatability.

In the present invention, the radical polymerizable monomer (C) used for the graft modification of (A) and (B) includes styrene compounds, vinyl group-containing carboxylic acids or derivatives thereof, (meth) acrylonitrile and the like. Is mentioned. Of these, styrene-based compounds and combinations of the styrene-based compounds with the above-mentioned other monomers are preferable from the viewpoint of thermal stability.

The styrene compounds include styrene, t
-Butylstyrene, α-methylstyrene, p-methylstyrene, chlorostyrene, bromostyrene, fluorostyrene, ethylstyrene, divinylbenzene, N, N-
And diethylaminostyrene. Particularly preferred among these is styrene.

Examples of the vinyl group-containing carboxylic acids or derivatives thereof include vinyl group-containing carboxylic acids [eg, (meth) acrylic acid, maleic anhydride, fumaric acid, itaconic acid, etc.] and (meth) acrylic acid esters [1 carbon atom. ~ 1
Alkyl of 8 (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 (carbon number) 2-6) (meth) acrylate, glycidyl (meth) acrylate, etc.], and imidized vinyl group-containing dicarboxylic acid [maleimide, N-methylmaleimide, N-butylmaleimide, N-phenylmaleimide, etc.]. Of these, (meth) acrylic acid, maleic anhydride and esterified products thereof are preferred.

In the present invention, (A) :( B) :( C)
Is usually 100: (30-300) :( 1-5
0), preferably 100: (50-200) :( 3-3
0). If the ratio of (B) is less than 30, the resulting composite resin will have a high viscosity, resulting in poor workability when used as a hot melt adhesive. If it exceeds 300, the rubber elasticity and oil retention of the composite resin composition will decrease. . Also,
When the ratio of (C) is less than 1, the cohesive strength becomes weak, and the strength and heat creep resistance of the composite resin composition become insufficient, and
If it exceeds 0, the melt viscosity of the composite resin composition becomes high and the processability becomes insufficient.

In the present invention, a (liquid) hydrogenated polybutadiene (D) can be contained, if necessary, in order to lower the viscosity of the composite resin composition and further improve the oil retention. When used, the content of (D) is usually 50% by weight or less, preferably 30% by weight or less.
When the proportion of (D) exceeds 50% by weight, the cohesive strength of the composite resin composition decreases, and the heat creep resistance becomes insufficient.

The method for producing the composition of the present invention is not particularly limited, and examples thereof include the following method. A method of mixing a polymer obtained by polymerizing (C) in the presence of (A) and a polymer obtained by polymerizing (C) in the presence of (B); a polymer obtained by polymerizing (C) in the presence of (B); A method of polymerizing (C) in the presence of (A); a method of polymerizing (C) in the presence of (A) and a method of polymerizing (C) in the presence of (B); (A) and ( A method of polymerizing (C) in the presence of B); Of these, the preferred method is the following method.

As the heat-melt kneader used for the polymerization,
The style and the like are not particularly limited, for example, a mixer having a highly compressible screw having a reverse threaded portion or a ribbon-shaped stirrer, a kneader, an extruder,
A mixer etc. can be mentioned. Among these, it is preferable to use a non-open type apparatus, and it is preferable to knead the mixture in an atmosphere of an inert gas such as nitrogen during polymerization.

Known polymerization initiators and organic solvents can be used for the polymerization, if necessary. As the polymerization initiator,
Organic peroxides such as ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and peroxyesters; and azo compounds such as azoisobutyronitrile. . 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 polymerization is not particularly limited, and may be any temperature at which the monomer can be substantially polymerized.
° C.

When the composition of the present invention is used as a hot melt adhesive, various known additives such as tackifiers (rosin derivatives, terpene resins, cumarone-indene resins, petroleum resins, etc.) , A wax (paraffin wax, microcrystalline wax, low molecular weight polyolefin wax, etc.), an antioxidant, a filler, a plasticizer, etc.].

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be further described below with reference to examples, but the present invention is not limited to these examples. In the following, “parts” indicates parts by weight.

[0022]

【Example】

Examples 1 to 5 and Comparative Examples 1 to 3 A continuous mixing device having a diameter of 5 inches and L / D = 10 (KRC manufactured by Kurimoto Tekko Co., Ltd.) with the heating medium temperature of the jacket set at 160 ° C.
Using S5), a mixture of a resin and a monomer dispersed in the ratio shown in Table 1 was supplied from a raw material supply port of a continuous mixing apparatus, and polymerization was performed while keeping the residence time at 10 minutes. The obtained mixture is subjected to a twin-screw extruder (PCM4 manufactured by Ikegai Iron Works).
5, L / D = 50), and the composite resin of the present invention and a comparative resin were produced.

[0023]

[Table 1] {St | MA | BPB | EPR | EBM | APAO | WAX} --------------------------------------------------------------------------- −−− Example 1 {100 | | 0.5 | || 400 | 500 |} Example 2 {100 | | 0.5 | | 350 | 350 | 200} Example 3 {100 | | 0.5 | | 350 | 450 | 100} Example 4 {200 | | 1.0 | | 250 | 350 | 200} Example 5 {50 | 50 | 0.5 | | 350 | 350 | 200} −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Comparative example 1 {130 | | | PE 100 | 100 | 比較 Comparative example 2} | | | SEBS100 | | ‖ Comparative Example 3 {100 | DCP 1.0 | 350 | | 450 | 100} −−−−−−−−−−−−−−−−−− --------------------The above-mentioned Example 1 is a reference example. (Explanation of symbols etc.) St: Styrene MA: Maleic anhydride BPB: t-butyl peroxy Benzoate EPR: ethylene-propylene copolymer (melt index 2, Nippon Synthetic Rubber's "EP912P") EBM: ethylene-butene 1 copolymer (melt index 35, Sumitomo Chemical's "Esprene N0377") APAO: amorphous Ethylene-propylene copolymer (crystallinity 5%, 190 ° C melt viscosity 1500 cP, “Ube Tack UT2315” manufactured by Ube Lexen) WAX: low molecular weight polypropylene (190 ° C melt viscosity 45 cps, Sanyo Chemical Industries, Ltd.) obtained by thermal degradation method PESC: crystalline high-density polyethylene (melt index 8) SEBS Hydrogenated styrene - butadiene block copolymer (melt index 1 or less) DCP: dicumyl peroxide

Test Example 1 The obtained composite resin composition was molded by an injection molding machine to prepare a test piece. Table 2 shows the physical properties of the resin measured using the test piece.

[0025]

[Table 2] (Measurement method) Tensile breaking strength: JIS K6301 (unit: kgf / c)
m ² ) Hardness: JIS K6301 (JIS A) MI (melt index): ASTM D1238-
L method

Test Example 2 80 parts of each of the obtained composite resins, 100 parts of tackifier (hydrogenated petroleum resin having a softening point of 100 ° C., “Imarb P-100” manufactured by Idemitsu Petrochemical) and process oil (“Diana” manufactured by Idemitsu Kosan Co., Ltd.) 20 parts of process PW-90), 1 part of an antioxidant (“Irganox 1010” manufactured by Ciba-Geigy) and an antioxidant (“ADK STAB 211” manufactured by Asahi Denka Kogyo)
2)) 1 part was melt-mixed to obtain a hot melt adhesive.
Table 3 shows the performance measurement results of the obtained adhesives. From these results, it can be seen that the heat creep resistance, the T-peel adhesive strength, and the oil retention were improved with respect to the comparative example.

[0027]

[Table 3] (Measurement method) Heat-resistant creep shear: Apply an adhesive to an aluminum plate at 25 × 25 mm and a thickness of 50 μm, and apply 100 ° C. × 10 sec ×
The polyester film was pressed under the condition of 1 kg / cm 2, and a creep test was performed at 60 ° C. under a shear load of 1 kg. (Unit: mm / hour) Heat-resistant creep T-peel: 25 on polyester film
× 25mm, 50μm thick, apply adhesive, 100 ℃
The polyester film was pressure-bonded under the conditions of × 10 sec × 1 kg / cm 2, and a T-type peeling creep test was performed at 50 ° C. under a load of 100 g. (Unit: mm / hour) T-type peel adhesion strength: 25 × 2 on polypropylene film
Apply adhesive at 5mm, thickness 100μm, 100 ℃ ×
A polypropylene film is pressure-bonded under the conditions of 10 sec × 1 kg / cm 2, 23 ° C., tensile speed 300 mm / min.
Was used to measure the T-peel strength. (Unit: g / 25 mm) Oil retention: 0.5 kg / cm after applying adhesive to filter paper
After applying a load of 2 and controlling the temperature at 50 ° C. for 24 hours, it was visually determined whether or not oil bleeding was observed on the filter paper. Evaluation criteria ○: no bleeding, Δ: slight bleeding, ×: bleeding

[0028]

The composite resin composition of the present invention has the following effects as compared with conventional ones. (1) Since the heat-resistant creep property is good, it is excellent in adhesion to a portion where a creep force is applied. (2) Since the oil retaining property is good, there is little problem of oil seeping out. (3) It shows excellent adhesion to various materials. In particular, it has good adhesiveness to difficult-to-bond materials such as polyolefin-based 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 the like. In addition, the composite resin composition of the present invention can be used as a plastic modifier, a sealant, a modifier of a thermosetting resin, an asphalt modifier, a compatibilizer of various compounds, and the like.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-49-9546 (JP, A) JP-A-1-236259 (JP, A) JP-A-63-270754 (JP, A) JP-A-63-270754 54478 (JP, A) JP-A-57-100105 (JP, A) JP-A-52-123443 (JP, A) JP-A-8-48731 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) C08F 255/00-255/08 C08L 51/06 C09J 151/06

Claims (6)

(57) [Claims] 1. An α-olefin homopolymer (A1) having a melt index of 1 to 100 according to the ASTM D1238-L method and / or an ethylene / α-olefin copolymer having a melt index of more than 10 and 100 or less according to the same method. Α-olefin (co) consisting of coalescing (A2)
Polymer (A) and low molecular weight polyp obtained by thermal degradation method
Crystallinity 1 obtained by propylene (co) polymer and polymerization method
19 % or less of a polypropylene (co) polymer
In the presence of a low-viscosity polyolefin resin (B) having a melt viscosity at 30C of 30 to 100,000 cP, at least one selected from the group consisting of a styrene compound, a vinyl group-containing carboxylic acid or a derivative thereof, and (meth) acrylonitrile. (A): (B): (C) by polymerizing a kind of radically polymerizable monomer (C) in a hot melt kneader.
Is a composite resin composition having a weight ratio of 100: (30-300) :( 1-50). 2. The composition according to claim 1, wherein (A) is a homopolymer of butene-1 and / or an ethylene-butene-1 copolymer.
A composition as described. 3. The method of claim 1, wherein (B) is a low molecular weight obtained by a thermal degradation method.
Contains at least 30% by weight of polypropylene and propylene units
Amorphous low molecular weight ethylene-propylene copolymer
Consisting claim 1 or 2 composite resin composition. 4. The composite resin composition according to claim 1, wherein (C) essentially contains a styrene compound. 5. A method according to claim 1, wherein the hydrogenated polybutadiene (D) is (A)
50% by weight or less based on the total weight of (B) and (C)
The composite resin composition according to any one of claims 1 to 4, wherein the composition comprises: 6. A hot melt adhesive comprising the composite resin composition according to claim 1.