JP6907090B2 - Hot melt adhesive composition - Google Patents

Description

The present invention relates to novel hot melt adhesive compositions.

Hot melt adhesives are used in various fields such as construction, electrical, and automobile fields because they can fix adherends only by cooling and solidifying after crimping and have high workability. .. Therefore, a highly functional hot melt adhesive is required.

For example, Patent Document 1 contains a butyl rubber (a), a styrene-based block copolymer (b), and an aromatic-modified terpene resin (c), and has high heat resistance, low viscosity, and excellent elasticity. Melt adhesives are disclosed.

Japanese Unexamined Patent Publication No. 2012-77251

However, although the hot melt adhesive as described above has excellent heat resistance, it has adhesiveness to both non-polar materials such as resin base materials for vehicle interior members and polar materials such as skin materials. It was difficult to simultaneously satisfy uniform coatability without coating spots.

As a result of diligent research, the present inventors have found that the above problems can be solved by using a hot melt adhesive containing a specific amount of a specific component, and have completed the present invention. That is, the present invention is as follows.

The present invention (1)
(A) Amorphous poly-α-olefin having a softening point of more than 100 ° C.
(B) Styrene-isoprene-styrene block copolymer (SIS) having an MFR (200 ° C., 4.9 kgf) of 15 g / 10 min or more and a styrene content of 20 wt% or less, and (C) MFR (230 ° C., 2. 16 kgf) contains styrene / ethylene / butylene / styrene block copolymer (SEBS) of 100 g / 10 min or more.
Of the total composition, the content of amorphous poly α-olefin _{(M A)} is 50 to 70 wt%, the content of the SIS _{(M B)} is 1 to 10 mass%, the SEBS the content of _{(M C)} is 0.5 to 10 wt%,
_{(M B + M C) /} M A is a hot melt adhesive composition being in the range of 5 / 100-25 / 100.
The present invention (2) is the hot melt adhesive composition of the present invention (2), which further contains a paraffinic oil having a viscosity of 300 cSt or more as an oil component.
The present invention (3) is a vehicle interior member laminated and bonded by the hot melt adhesive composition according to any one of the above inventions (1) and (2).

According to the present invention, it is possible to provide a hot melt adhesive that satisfies all of adhesiveness, uniform coatability, and heat resistance to both non-polar materials and polar materials.

Next, the present invention will be specifically described in the following order, but the present invention is not limited thereto.
1 Hot-melt adhesive composition 1-1 Ingredients 1-2 Blending amount 1-3 Physical properties 1-4 Properties / Applications 2 Manufacturing method of hot-melt adhesive composition 3 Application method of hot-melt adhesive composition

≪Hot melt adhesive composition≫
The components, blending amount, physical properties, properties and uses of the hot melt adhesive composition according to the present invention will be described.

<Ingredients>
The hot melt adhesive composition according to the present invention contains (A) amorphous polyα-olefin, (B) SIS, and (C) SEBS as a base polymer, and may contain other components.

(Amorphous poly-α-olefin)
As the amorphous poly-α-olefin, known ones, for example, those described in Japanese Patent No. 6001658, Japanese Patent No. 3153648, etc. can be used. More specifically, the amorphous polyα-olefin is, for example, an amorphous olefin polymer obtained by homopolymerizing propylene, propylene, ethylene, and 1-butene or copolymerizing any combination thereof. ..

Here, it is preferable that the softening point of the amorphous poly-α-olefin is more than 100 ° C. By setting the softening point of the amorphous poly-α-olefin within this range, it is possible to increase the heat resistance while maintaining the adhesiveness with the non-polar resin. From such a viewpoint, the softening point of the amorphous poly-α-olefin is more preferably 165 ° C. or lower. The softening point was measured according to JIS K6863 (a softening point test method for hot melt adhesives, a ring ball method).

(SIS polymer)
The SIS polymer according to the present invention is a styrene-isoprene (SI) block copolymer (such a polymer may be simply referred to as SIS). The SIS according to the present invention has an MFR (200 ° C., 4.9 kgf, based on JIS K 7210) of 15 g / 10 min or more (preferably 17 g / 10 min or more, more preferably 19 g / 10 min or more). The upper limit of the MFR of SIS is not particularly limited, but may be 50 g / 10 min or less. In order to adjust the MFR of SIS, the molecular weight may be adjusted.

Further, the SIS according to the present invention has a styrene content of 18 wt% or less. The lower limit of the styrene content is not particularly limited, but is, for example, 8 wt% or more. Within the range of the above MFR, high fluidity in the present invention can be obtained, and coatability such as spray coating and brush coating becomes high. On the other hand, when the styrene content is within the numerical range, the compatibility between the other resin, that is, SEBS and the amorphous poly-α-olefin is high, and the moldability is excellent.

As the SIS, known ones can be used, and for example, SIS5403P (manufactured by JSR Corporation, styrene content: 15%), VECTOR4114N (manufactured by TSRC, styrene content: 15%) and the like can be used.

(SEBS polymer)
The SEBS polymer according to the present invention is a styrene / ethylene / butylene (SEB) block copolymer (such a polymer may be simply referred to as SEBS). The SEBS according to the present invention has an MFR (230 ° C., 2.16 kgf, conforming to JIS K 7210) of 100 g / 10 min or more (preferably 150 g / 10 min or more). The upper limit of the MFR of SEBS is not particularly limited, but may be 400 g / 10 min or less. In order to adjust the MFR of SEBS, the molecular weight may be adjusted.

As such a SEBS, a known one can be used, and for example, it may be prepared by referring to Japanese Patent No. 6001658 and the like. The SEBS exhibiting this high fluidity is hydrogenated, and a radial polymer having three branched chains is bonded to one end thereof.

The styrene content of SEBS according to the present invention is not particularly limited, and may be, for example, 5 wt% to 45 wt% (preferably 5 wt% to 30 wt%).

(Other ingredients)
As other components, known additives used in hot melt adhesives, for example, oil components (plasticizers), tackifier resins, antioxidants, heat stabilizers, fillers, waxes and the like can be blended.

-Oil component The hot melt adhesive composition according to the present invention preferably contains an oil component as a plasticizer. By blending such an oil component, it is possible to improve the applicability of a spray or the like and the compatibility with the base resin. Examples of the oil component include paraffin-based oils, naphthenic oils, aromatic oils, and the like, and mixtures thereof may be used. In addition, vegetable oil or the like may be used as an oil component. These oil components can be added in an amount of 0.5% by weight to 10% by weight. It is preferably 1.0% by weight to 5% by weight, and more preferably 1.3% by weight to 2.0% by weight. Paraffin oil is more preferable as the oil component from the viewpoint of further improving the compatibility with the base resin, and paraffin oil having a viscosity of 300 cSt or more is particularly preferable. At this time, the composition of the present invention preferably has a viscosity of 50 Pa · s or less at 180 ° C. by a rheometer. Viscosity follows JIS K 2283 crude oil and petroleum products-kinematic viscosity test method and viscosity index calculation method.

・ Adhesive-imparting resin As the adhesive-imparting resin, aliphatic petroleum resin, aromatic petroleum resin, hydrogenated aliphatic petroleum resin, hydrogenated aromatic petroleum resin, terpene resin, styrene resin, rosin resin and One or more kinds of tackifier resins selected from the group consisting of these modified resins can be exemplified.

-Antioxidants As antioxidants, phenol-based antioxidants (for example, Irganox1010 (manufactured by BASF)), sulfur-based antioxidants (for example, SUMILIZER TP-D (manufactured by Sumitomo Chemical Co., Ltd.)) and phosphorus-based antioxidants. Examples thereof include agents (for example, Irgafos 168 (manufactured by BASF), JP-650 (manufactured by Johoku Chemical Co., Ltd.)).

-Wax Wax includes natural wax (for example, animal wax (mitsuro, whale wax, etc.), plant wax (wood wax, etc.), petroleum wax (paraffin wax, etc.)}, and synthetic wax {for example, synthetic wax. Examples thereof include hydrocarbons (low molecular weight polyethylene, etc.), fatty acid esters (polyethylene glycol, etc.)}.

<Mixing amount>
The content of amorphous poly α-olefin _{(M A),} relative to the total composition is 50 to 70 wt%, preferably from 55 to 70 wt%.

The content of the SIS _{(M B),} relative to the total composition, from 1 to 10 wt%, preferably 2-9 wt%.

The content of SEBS _{(M C),} relative to the total composition is 0.5 to 10 wt%, preferably 1 to 10 wt%, more preferably 1 to 5 mass%.

_Also, the _{(M B + M C) /} M A, in the range of 5 / 100-25 / 100, preferably has 6 / 100-23 / 100.

By setting each blending amount within the above range, SEBS particularly enhances the compatibility between the amorphous polyα-olefin and SIS, and has adhesiveness, wettability, heat resistance, and uniform coating to non-polar materials such as PP. It is possible to obtain a hot melt adhesive composition having excellent properties and peeling strength.

Here, when other components are contained, the content thereof is not particularly limited, but for example, the total content of the other components may be 10% by mass or more with respect to the entire composition. When an oil component is contained, for example, it may be 0.5 to 5% by mass or the like with respect to the entire composition. When the tackifier resin is contained, for example, it may be 10 to 40% by mass or the like with respect to the entire composition.

<Physical characteristics>
The hot melt adhesive composition according to the present invention has a viscosity of 50 Pa · s or less at 180 ° C. according to a rheometer. The lower limit of the viscosity is not particularly limited, but is, for example, 2.0 Pa · s or more. By setting the viscosity in such a range, a hot melt adhesive composition particularly preferable for spray coating can be obtained. As described above, the hot melt adhesive composition according to the present invention has high fluidity because it contains a specific amount of a specific component, but if it is desired to further adjust the viscosity, the above other components or A low-viscosity olefin resin or the like may be added.

<Characteristics / Applications>
The hot melt adhesive composition according to the present invention not only has excellent heat resistance, but can also bond a non-polar material (for example, PP or the like) to a polar material (for example, nylon cloth or urethane foam). Further, since it can be applied uniformly and stably, it is possible to suppress the occurrence of unevenness and improve the appearance quality even when it is applied to an adhesive. Further, since it has a predetermined fluidity, it can be suitably used for spray coating. Further, since the hot melt adhesive composition according to the present invention is a non-reactive type, it is excellent in handleability (packability, detergency, storability). As described above, since the hot melt adhesive composition according to the present invention has excellent properties, it can be applied to various adhesive applications such as adhesion of mattresses and building materials. In particular, since it can be spray-applied, it can be applied regardless of the shape of the object to be bonded, it can be applied to bond polar materials and non-polar materials, and it has excellent heat resistance. It can be suitably used for fixing interior members of vehicles (automobiles, railroad vehicles), etc., and can be used more preferably for fixing interior members for vehicles, and the skin of automobile interior members (instrument panels, pillars, door trims, etc.). It can be used particularly preferably for fixing. For example, in an interior member for a vehicle, a woven fabric as a skin material and a foam sheet such as urethane slab are laminated by flame welding to form a skin pad material, and further, the skin pad and an automobile made of a non-polar olefin material. The base material of the instrument panel and door trim of the above is joined with an adhesive to make an interior material. That is, the present invention is used as an adhesive for laminating and adhering the skin pad material of the polar material and the base material of the non-polar material. In other words, the laminated material in which the skin pad material of the polar material and the base material of the non-polar material are laminated via the cured product of the adhesive of the present invention can be used as an automobile interior member. In addition, there is also an interior material that directly adheres a skin material to be a woven fabric and a base material such as the door trim.

≪Manufacturing method of hot melt adhesive composition≫
The method for producing the hot melt adhesive composition is not particularly limited, and the hot melt adhesive composition can be produced by a known method. For example, the above-mentioned raw materials are put into a continuous kneader such as a single-screw or twin-screw extruder, or a batch-type kneader such as a roll, a Banbury mixer, a kneader, a planetary mixer, or a high-shear Z-blade mixer, and kneaded for a predetermined time. do it.

≪How to apply hot melt adhesive composition≫
Next, an example of a specific application method of the hot melt adhesive composition according to the present invention will be described. In this example, a case where the hot melt adhesive composition is spray-coated will be described, but the method of applying the hot melt adhesive composition according to the present invention is not limited to this, and a known method is applied to the surface to be bonded. It may be applied.

First, the hot melt adhesive composition according to the present invention is held in a molten state (melting step). Next, the hot-melt adhesive composition in a molten state is spray-coated on at least one of the surfaces to be bonded so as to have a desired coating amount (coating step). As the spray method, known methods such as curtain spray, omega spray, spiral spray, summit spray and the like can be applied. After the coating step, the hot melt adhesive composition is cooled and solidified by keeping the other surface to be bonded pressed against the surface to be bonded (solidification step). Before the coating step, a known surface treatment may be applied to the surface to be bonded.

Hereinafter, the effects of the hot melt adhesive composition of the present invention will be specifically described with reference to Examples.

≪Manufacturing of hot melt adhesive composition≫
The following raw materials were prepared.

(A) Poly-α-olefin a-1: Vestoplast 408 (EVONIK) Softening point 118 ° C.
a-2: Vestoplast 508 (EVONIK) Softening point 84 ° C.

(B) SIS
b-1: Styrene content 15 wt% 20 g / 10 min (200 ° C, 4.9 kgf)
b-2: Styrene content 24 wt% 20 g / 10 min (200 ° C, 4.9 kgf)
b-3: Styrene content 16 wt% 13 g / 10 min (200 ° C, 4.9 kgf)

(C) SEBS
c-1: Styrene content 20 wt% 220 g / 10 min (230 ° C, 2.16 kgf)

(D) Adhesive-imparting resin d-1: T-Rez HA-105 (TonenGeneral Co., Ltd.) Hydrogenated aliphatic petroleum resin, softening point 105 ° C.
d-2: T-Rez RC115 (TonenGeneral Co., Ltd.) Aliphatic petroleum resin, softening point 105 ° C.

(E) Process oil e-1: PW-90 (Idemitsu Kosan Co., Ltd.) Paraffin-based process oil, viscosity 95.5 cSt
e-2: PW380 (Idemitsu Kosan Co., Ltd.) Paraffin-based process oil, viscosity 380 cSt

(F) Antioxidant f-1: Irganox1010 (BASF) Phenolic antioxidant f-2: Irgafos168 (BASF) Phosphorus-based anti-aging agent

The above-mentioned raw materials were kneaded at 180 ° C. for 15 minutes in a planetary mixer at the blending amounts shown in Table 1 to obtain hot melt adhesive compositions according to each Example and each Comparative Example. The viscosities of each composition at 180 ° C. by the rheometer are also shown in Table 1.

≪Evaluation≫
The hot melt adhesives according to each example and each comparative example were evaluated according to the following.

<Fabric adhesion test>
-Sample preparation The adhesive of the present invention was put into a raw material tank of a coating device (manufacturer name: Nordson), and the temperature was adjusted by heating at 185 ° C. for 20 minutes. A polypropylene resin plate was spray-coated with a spray nozzle so that the adhesive surface had a length of 100 mm and a width of 1 inch. The basis weight was 50 g / m ² . A fabric fabric (a suede-like fabric made of 100% rayon brushed) was laminated so as to cover the adhesive surface, and a weight of 10 kg was placed on the adhesive surface for 15 seconds to crimp the entire surface of the adhesive surface. Then, the weight was removed, and the mixture was cured in one daily condition (23 ° C., 50% RH) to obtain a sample.
-Observation of surface irregularities In the above sample preparation, the appearance of the test piece after the adhesive surface was fully crimped and then weight-reduced was visually observed. Those with no irregularities on the surface of the test piece were marked with ◯, and those with irregularities were marked with x.
-Normal peel strength of fabric The normal peel strength was measured based on JIS K6854.
-Dough 80 ° C. peeling strength Based on JIS K6854, the above sample is left in an 80 ° C. furnace for 1 hour or more, and then the peeling test is performed as it is.

<Urethane adhesion test>
The test was carried out in the same manner as the fabric adhesion test except that the objects to be adhered were PP plate and urethane foam. For the urethane foam, EL-67F manufactured by Inoac Corporation, which is a flexible polyurethane foam for frame laminating of a polyether type, has an apparent density of 20 kg / m3, a hardness of 100 N, and a thickness of 2.0 mm was used.

The following can be seen from Table-1.
First, it can be seen that the adhesive composition according to the present invention has sufficient peel strength by adhering a resin plate to a woven fabric or a urethane foam. (See Examples 1 to 3). The adhesive composition according to the present invention has a predetermined viscosity and is therefore excellent in coatability.
On the other hand, in Comparative Examples 1 and 2, since SIS was not included, peeling occurred in the adhesion with the urethane foam at 80 ° C. In Comparative Example 3, the peel strength at 80 ° C. could not be obtained because the total number of portions of SIS and SEBS added was excessive with respect to the amorphous poly-α-olefin. In Comparative Example 4, the styrene content of SIS was as large as 24% by weight, so that the test piece had interfacial peeling. In Comparative Example 5, peeling occurred by using a component having a low MFR for SIS. In Comparative Examples 6 and 7, sufficient adhesive strength could not be obtained because the amount of the amorphous poly-α-olefin added was too small or excessive. In Comparative Example 8, the softening point of the amorphous poly-α-olefin was low and sufficient adhesive strength could not be obtained.

Claims (3)

(A) Amorphous poly-α-olefin having a softening point of more than 100 ° C.
(B) Styrene isoprene block copolymer (SIS) having an MFR (200 ° C., 4.9 kgf) of 15 g / 10 min or more and a styrene content of 20 wt% or less, and (C) MFR (230 ° C., 2. 16 kgf) contains styrene ethylene butylene block copolymer (SEBS) of 100 g / 10 min or more.
Of the total composition, the content of amorphous poly α-olefin _{(M A)} is 50 to 70 wt%, the content of the SIS _{(M B)} is 1 to 10 mass%, the SEBS the content of _{(M C)} is 0.5 to 10 wt%,
_{(M B + M C) /} M A , characterized in that it is in the range of 5 / 100-25 / 100, the hot melt adhesive composition. The hot melt adhesive composition according to claim 1, further comprising a paraffinic oil having a viscosity of 300 cSt or more as an oil component. A vehicle interior member laminated and bonded by the hot melt adhesive composition according to claim 1 or 2.