JP4593956B2 - Re-adhesive hot melt adhesive - Google Patents

Description

The present invention relates to an adhesive having re-adhesiveness, and more specifically, when a product is transferred from a transport container to the main container, temporary fixing such as temporary fixing in construction or work, or replacement in advance is planned. The present invention relates to a hot melt adhesive having re-adhesive properties for fixing parts.

Conventionally, various solvent adhesives have been widely used. However, the use of solvents causes problems such as air pollution, fire hazard, and deterioration of working environment and hygiene. Therefore, solventless adhesives are widely used. Typical examples of the solventless adhesive include an aqueous adhesive in the form of an aqueous solution or an aqueous dispersion and a hot melt adhesive used by heating and melting. Compared to solvent-type adhesive compositions, hot-melt-type adhesive compositions have the advantage that a solvent drying device and recovery device are not required. Packaging, bookbinding, sanitary materials, plywood It is widely used in various industries such as woodwork, building materials and automobiles.

A normal hot melt adhesive is solid at normal temperature, and is heated and melted at the time of use, applied to various base materials, and solidified by cooling to develop an adhesive force. Because it is a non-solvent type consisting of a thermoplastic resin that does not contain water or solvent, it is preferable in terms of working environment and hygiene without air pollution and fire hazard, and because the set time for bonding is shortened, paper, wood, It is widely used industrially for bonding metals and plastics.

However, due to differences in physical and chemical properties such as the heat resistance of the adherend and the adhesion to the hot melt adhesive, there are many cases where it cannot be applied with a single hot melt adhesive. For example, the problem related to the adhesion of plastics such as polyethylene resin and metals such as aluminum is that the required adhesive strength can be obtained for adhesives and plastics that are usually lipophilic, but metals such as aluminum are sparse. This is the case where sufficient adhesive strength cannot be obtained because it is oily, or when plastics having greatly different melting points or softening points are bonded together.

In the present invention, the intended re-adhesiveness is, for example, when a product is transferred from a transport container to the main container, temporarily fixed such as temporarily fixed in construction or work, or a part that is scheduled to be replaced in advance. It is useful for fixing and may be used in other fields. To date, in the field of hot-melt adhesives, only adhesive strength, productivity, and mechanical suitability have been studied, and there has been no example of re-adhesion.

In addition, a method of fixing with a sticky substance for re-adhesion has been devised, but in general, sticky substances are remarkably inferior in usability due to severe stringing at the time of adhesive application and peeling. Also, there are problems such as difficult machine setting even when an adhesive is applied industrially. Further, since an oily substance is used as the sticky substance, there is a problem that even a hot melt adhesive has different adhesive strength due to the problem of lipophilicity.

As for other re-adhesion methods, there is a temporary fixing method using a vacuum such as a denture stabilizer, but this method depends on the smoothness of the adhesive surface, so if the surface is rough, Since there are few parts, sufficient adhesiveness cannot be obtained. In this case, in order to obtain sufficient adhesion, it is necessary to make the adhesive body very low in viscosity, so that sufficient adhesive strength cannot be obtained due to deformation of the adhesive body.
JP-A-8-85289 Japanese Patent Laid-Open No. 11-100085 JP 2003-31688 A

The problem to be solved is that it can be re-adhered even if it is peeled off once adhered, and the adhesive strength is the same even on the oleophilic and oleophobic surface. It is to provide a composition corresponding to bonding and fixing.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention obtained a composition obtained by containing 12-hydroxystearic acid together with polybutene by heating and then using it as an adhesive. Adhesive composition that can be re-adhered and can be bonded and fixed with relatively low strength, which has the same adhesive strength as conventional adhesives even on lipophilic and oleophobic surfaces such as plastic and metal. In addition, the inventors have found that the composition is characterized in that it has a characteristic that it is a composition with little threading, good usability during re-adhesion, and easy machine setting.

The feature of the present invention is that it is non-curing type adhesion at room temperature unlike ordinary hot-melt adhesives, so that it can be re-adhered at room temperature. The composition of the present invention is solidified because it is gelled by cooling after heating and melting, but since it is originally liquid, the gel partially disintegrates and liquefies due to the external force of re-adhesion to obtain an adhesive effect be able to. Therefore, it is possible to provide a wide range of adhesives useful for transferring a product from a transport container to a main container, temporary fixing such as temporary fixing in construction and work, and fixing parts scheduled to be replaced in advance.

The polybutene used in the present invention is not particularly limited as long as it is a copolymer obtained by copolymerizing isobutylene and a small amount of butene-1, published by the Japan Food Additives Association "Food Additives Official Version 7". The listed polybutene is preferred.

Further, the content of polybutene used in the present invention needs to be 20 to 80 parts by weight. When the content of polybutene is less than 20 parts by weight, the low-temperature adhesive force, flexibility, re-adhesion and the like of the obtained hot melt adhesive composition are not sufficiently improved. Thus, the solubility of 12-hydroxystearic acid is lowered, and uniform gelation cannot be obtained as a whole, so that the stringiness cannot be improved and the usability is lowered.

The 12-hydroxystearic acid used in the present invention is not particularly limited, and hydroxystearic acid and the like listed in “Cosmetic Variety-Specific Ingredients” published by Yakuji Nippo Inc. can be used.

Moreover, 0.1-10 weight part is required for content of 12-hydroxystearic acid used for this invention, More preferably, it is 1-5 weight part. When the content of 12-hydroxystearic acid is less than 0.1 parts by weight, the resulting hot-melt adhesive composition of the present invention is insufficiently gelled, and the stringiness of polybutene appears strongly, so that it can be used. Decreases. Conversely, if it exceeds 10 parts by weight, gelation is strongly developed and the re-adhesion effect cannot be obtained.

In the present invention, the oil and / or wax, which is an oil component to be blended as an adhesive strength modifier, is not particularly limited, but there is no problem with the compatibility of 12-hydroxystearic acid and polybutene. Vegetable oils such as olive oil, jojoba oil, castor oil, rice bran oil, coconut oil, animal oils such as squalane, beef tallow and lanolin, synthetic oils such as silicon oil, polyisobutene, polyisoprene, fatty acid ester, Fatty acid glycerin, etc. as waxes, beeswax, mole, candelilla wax, carnauba wax, etc., hydrocarbons as liquid paraffin, ceresin, microcrystalline wax, petrolatum, etc., higher alcohols as cetanol, stearyl alcohol, octyldodecanol, etc. Higher fatty acids Is then, isostearic acid, lauric acid, myristic acid, and oleic acid. When there is a problem in compatibility, a phenomenon occurs in which the oil component bleeds and peels off the bonded surface after bonding by the hot melt method.

The product of the present invention can be blended with an antioxidant when heated for a long time. Examples of the antioxidant to be blended include dibutylhydroxytoluene, butylhydroxyanisole, tocopherol and the like.

The method for producing the hot-melt adhesive composition of the present invention is not special. For example, a predetermined amount of the above-mentioned various blended components are put into a mixer equipped with a heating device and a stirring device, and melted by a conventional method. By stirring and mixing uniformly, a desired hot-melt adhesive composition can be easily obtained.

EXAMPLES The present invention will be specifically described below with reference to examples, but the technical scope of the present invention should not be construed as being limited thereto. In addition, all the compounding quantities of the composition shown in the following table | surface are shown by weight%.

[Evaluation]
The evaluation was performed in the following two stages.
○ ・ ・ ・ Good, × ・ ・ ・ Bad

About the Example and the comparative example, it heat-mixed according to the conventional method, and obtained the sample. In addition, the used raw material is Nippon Petrochemical Co., Ltd. Holyten HV-1900, Kawaken Fine Chemical Co., Ltd. 12-hydroxystearic acid, American Witco Co., Ltd. carnation # 70, Nikko Rica Co., Ltd. ceresin 810.

Using the above sample, a high-density polyethylene plate and an aluminum plate were bonded and evaluated. The surface of the aluminum plate is anodized. In the bonding method, the sample is heated to 90 ° C., and 0.4 g is dropped on a high-density polyethylene plate, and the sample is held by an aluminum plate so that the sample becomes a circle having a diameter of 1 cm. Five samples were prepared for each sample, and evaluated whether the adhesive strength and re-adhesion were possible, and whether there was no stringiness and good usability. The adhesive strength was measured by storing the load at 20 ° C. for 4 hours after bonding, and then measuring the load when peeling the high-density polyethylene plate and the aluminum plate using a rheometer NRM-2002J manufactured by FUDO. At that time, the weight of the sample remaining on the aluminum plate was measured, and the residual ratio was calculated. Regarding the remaining rate, a value close to 50% seems to be a good result with no difference in the adhesion of different materials between a plastic such as polyethylene and a metal such as aluminum.

As a result of the above evaluation, Examples 1 to 5 were intended compositions with good re-adhesiveness and no drag and good usability. About Comparative Example 1, since there were few compounding of the polybutene which governs basic adhesion performance, adhesive force and re-adhesiveness were bad. In addition, a phenomenon of oil bleeding on the aluminum plate side was observed. In Comparative Example 2, since there was too much polybutene, stringing was severe and the usability was difficult. In Comparative Example 3, since 12-hydroxystearic acid was not blended, stringing was severe, the residual rate on the aluminum plate was low, and the re-adhesion effect was not obtained. About Comparative Example 4, since it gelled violently, most of the samples were attached to either side when peeled, or the gel did not collapse due to external force, and stable re-adhesiveness could not be obtained. It was.

Conventional gold pan-fixed pastes are used as a self-made or commercially available mixture of ceresin, polybutene, paraffin oil or the like, or a mixture obtained by adding modified starch to the above mixture. Ordinary metal pans are also used in the hot melt method. For fixing the metal pan, aluminum or stainless steel filled with bulk cosmetics is discharged after discharging the heated paste into a compact container or replacement container. Place a metal pan, and cool and solidify by natural cooling. With an ordinary metal pan fixing ladle, when replacing, the ladle hardly remains on the metal pan, and stable re-adhesiveness cannot be obtained. And when the gold-plated ladle composition obtained by this invention was used by the hot-melt method, the stable re-adhesion force was obtained. Moreover, since the transparency was good, the confirmation of printing on the back of the metal pan was good.

When this adhesive composition was applied in advance to a part to be temporarily fixed, it was highly convenient because it could be re-adhered at any time.

This paste composition for fixing a replacement part is highly convenient because the parts being transported are not damaged or lost.

The present invention can be used in various industrial fields, for example, when daily goods are stored and transported from the transport container to the main container, temporary fixing such as temporary fixing in construction and work, or replacement in advance. This is useful for fixing parts that are scheduled to be used in other fields.

Claims (2)

A hot melt adhesive composition comprising 0.1 to 10.0 parts by weight of 12-hydroxystearic acid, 20 to 80 parts by weight of polybutene, and oil and / or wax as an adhesive strength modifier. object. Oil and / or wax as an adhesive strength modifier is olive oil, jojoba oil, castor oil, rice bran oil, coconut oil, squalane, beef tallow, lanolin, silicon oil, polyisobutene, polyisoprene, fatty acid ester, fatty acid glycerin, wax, beeswax, The hot melt type according to claim 1, which is selected from molasses, candelilla wax, carnauba wax, liquid paraffin, ceresin, microcrystalline wax, petrolatum, cetanol, stearyl alcohol, octyldodecanol, isostearic acid, lauric acid, myristic acid, oleic acid. Adhesive composition.