JPH0713227B2 - Anti-adhesion agent for hot melt adhesives - Google Patents

Description

TECHNICAL FIELD The present invention relates to an anti-adhesion agent for hot melt adhesives.

(Prior art) In general, adhesives cure and adhere due to solvent volatilization, chemical reaction, etc., whereas hot-melt adhesives cure and adhere by heating and melting and cooling. Therefore, it has many excellent characteristics such as fast adhesion, wide range of adhesion, safety, harmlessness, and economical. For this reason, the fields of application of hot melt adhesives have recently been increasing in food,
Cartons and seals for chemicals, toys and various parts,
Box making of various paper containers Packaging for corrugated cardboard cases, bag making, phonebooks, magazines, booklets, etc.
For binding various kinds of documents such as spine binding, furnishing for furniture and cabinets, pasting cores for plywood, pasting decorative paper and decorative items, adhering aluminum sashes, woodworking construction, other can manufacturing, shoe manufacturing , Has expanded into a wide range of fields such as automobiles, electric parts, and general work such as do-it-yourself carpenters, and its demand has increased, but at the same time, problems due to hot melt adhesives have arisen.

That is, the hot melt adhesive is made of a thermoplastic material which is solid at room temperature, and includes, for example, polyethylene and its copolymers, polyesters, polyvinyl acetate and its copolymers, butyral, polymethylmethacrylates, polyvinyl ethers, polyurethanes. The system and the polycarbonate type are widely used.

These pot melt adhesives are melted in an applicator generally called an applicator, directly applied to an adherend in a molten state, and then cooled and solidified.

The molten hot-melt adhesive may be applied to the adherend completely, but in reality, it may run off or stick out from the adherend, and may be in a place other than the adherend, such as a metal part of the coating machine or May adhere to synthetic resin parts.

The hot melt adhesive adhered to the applicator or the like instantly solidifies to cause a situation in which the applicator is soiled or causes trouble. However, the solidified hot melt adhesive is difficult to remove due to its nature, and it is dangerous and too laborious to remove it by melting it by applying heat again and removing it, or scraping it in the solidified state, Moreover, it cannot be completely removed.

(Problems to be Solved by the Invention) Therefore, a method of chemically dissolving and removing the solidified hot melt adhesive may be considered. However, since the main component of the hot melt adhesive is a resin, for example, a coating machine When attempting to dissolve and remove the hot melt adhesive adhering to the synthetic resin portion, the problem occurs that the synthetic resin portion is also dissolved at the same time as the hot melt adhesive is melted.

Thus, there is a demand for a hot-melt adhesive remover that completely removes the hot-melt adhesive and that satisfies the condition that the material of the removed portion is not damaged, but a sufficient one has not been obtained yet.

On the other hand, as described above, it is also possible to pre-apply the anti-adhesion agent for the hot-melt adhesive on the portion where the troublesome hot-melt adhesive may adhere.

However, the parts to which the hot melt adhesive may adhere are various in terms of materials such as metals and synthetic resins, and in terms of temperature, from room temperature to a high temperature around 200 ° C. which is the melting point of the hot melt. The difference is large. As described above, it is difficult to apply the composition to a portion having a large difference in terms of material and temperature so as not to lower the adhesion preventing ability of the hot melt adhesive for a long period of time, and still satisfy these conditions. No such hot melt anti-adhesive agent has been developed.

Therefore, the present invention provides a hot-melt adhesive in which the anti-adhesion ability of the hot-melt adhesive does not decrease over a long period of time even if it is applied to various materials or a portion having a large temperature difference. The purpose is to develop an anti-adhesion agent.

(Means for Solving the Problems) Then, in order to achieve the above object, as a result of earnest research, the present invention is a hot melt obtained by dissolving an oil-soluble silicone oil and a water-soluble silicone oil in a flon solvent. An adhesive anti-adhesive agent is proposed.

That is, according to the study by the inventors of the present application, in a portion where the temperature is close to 200 ° C., adhesion can be prevented by applying an oil-soluble silicone oil having excellent heat resistance that is less decomposed and evaporated by heat. However, when the material is synthetic resin, it does not have a sufficient anti-adhesion effect, and water-soluble silicone oil has an excellent anti-adhesion effect on synthetic resins, but it is weak to heat and near 200 ° C, Decomposition or evaporation may occur and the anti-adhesion effect may not be maintained.

However, according to the present invention, by dissolving the oil-soluble silicone oil and the water-soluble silicone oil in a CFC-based solvent in a specific ratio according to the purpose, an oil-soluble silicone oil showing an excellent anti-adhesion effect in a high temperature portion is obtained. The characteristics of silicone oil and water-soluble silicone oil, which has an excellent anti-adhesion effect on materials such as synthetic resins, are fully utilized, and it is possible to obtain one that satisfies all the conditions that should be provided as an anti-adhesion agent for hot melt adhesives. Was found.

As the oil-soluble silicone oil that can be used in the present invention, those having excellent heat resistance are desirable, and dimethyl silicone, alkyl-modified silicone oil, epoxy-modified silicone oil, amino-modified silicone oil, carboxy-modified silicone oil, alcohol-modified silicone oil ( OH group 1.4% or less), fluorine-modified silicone oil, oil-soluble alkyl polyether modified silicone oil (ethylene oxide content 40% or less), oil-soluble epoxy polyether modified silicone oil (ethylene oxide content 40% or less), etc. Alternatively, two or more kinds can be used in combination.

As the water-soluble silicone oil, a kind of polyether modified silicone oil modified with dimethyl silicone oil and containing 40% or more of ethylene oxide, water soluble alkyl polyether modified silicone oil, water soluble epoxy polyether modified silicone oil, etc. Alternatively, two or more kinds can be used in combination.

The CFC-based solvent used as the solvent in the present invention is
It is preferable because it has relatively little toxicity, a high evaporation rate, and no flammability.

Specifically, trichlorofluoromethane (CFC 11: boiling point 2
3.8 ℃), dichlorofluoromethane (CFC21: boiling point 8.9)
℃), pentachlorofluoroethane (Freon 111: Boiling point 13
7.2 ° C), 1,1,2,2-tetrachlorodifluoroethane (CFC 112: boiling point 92.8 ° C), 1,1,1,2-tetrachlorodifluoroethane (CFC 112a: boiling point 90.6 ° C), 1,1,2- Trichlorotrifluoroethane (Freon 113: Boiling point 47.6 ° C), 1,
1,1-trichlorotrifluoroethane (CFC 113a: boiling point
45.7 ° C), 1,2-dichlorotetrafluoroethane (CFC 114: boiling point 3.6 ° C), 1,1-dichlorotetrafluoroethane (CFC 114a: boiling point 3.6 ° C), 1,2-dibromotetrafluoroethane (CFC 114B ₂₎ : Boiling point 47.5 ° C, 2,2-dichloro-1,1,1-trifluoroethane (CFC 123: Boiling point 28.7)
℃), 2-chloro-1,1,1-trifluoroethane (CFC 133a: boiling point 6.1 ° C), 1,1-dichloro-1-fluoroethane (CFC 141b: boiling point 32.0 ° C) and their homologues. be able to.

Of these, particularly preferred are Freon 113, Freon 113a,
It is a CFC solvent with a boiling point in the range of 40 to 50 ° C, such as CFC 114B ₂ .

This invention is one in which an oil-soluble silicone oil and a water-soluble silicone oil are added and dissolved in a chlorofluorocarbon-based solvent.
When the amount is 5 Wt% or less and 0.1 Wt% or less, a sufficient anti-adhesion effect cannot be obtained, and even when it is 5 Wt% or more, the anti-adhesion effect does not change, and the surface becomes sticky, which is inconvenient.

Furthermore, the mixing ratio of the oil-soluble silicone oil and the water-soluble silicone oil is appropriately determined depending on the properties of the surface to which this agent is applied.

For example, in the case of metal parts such as aluminum, where the emphasis is on preventing adhesion to parts that reach high temperatures around 200 ° C, the mixing ratio should be such that oil-soluble silicone oil is blended more than water-soluble silicone oil. The ratio is 1 to 3 parts by weight of the latter and 2 to 3 parts by weight of the former. If the emphasis is on preventing adhesion to plastics or low temperature parts, the above proportions may be mixed.

(Effects of the Invention) That is, the anti-adhesion agent of the hot melt adhesive according to the present invention can be used for all materials, and can maintain its performance for a long time without impairing its performance even at a high temperature portion of 200 ° C. By applying such an anti-adhesion agent for a hot melt adhesive in advance to a portion or the like where the hot melt adhesive does not adhere, it is possible to prevent stains and troubles caused by the hot melt adhesive.

(Examples) Examples of the present invention will be shown below, but the present invention is of course not limited to these examples.

Formulation 1 Dimethyl silicone oil (10,000cst) 2.0Wt% Polyether-modified silicone oil 1.0Wt% Freon 113 97.0Wt% Formulation 2 Alkyl-modified silicone oil 1.5Wt% Epoxy polyether-modified silicone (containing 60% ethylene oxide) 3.0Wt % Freon 113 95.5Wt% Comparative formulation example 1 Dimethyl silicone (10,000cst) 3.0Wt% Freon 113 97.0Wt% Comparative formulation example 2 Polyether-modified silicone oil 3.0Wt% Freon 113 97.0Wt% Sample obtained by the above formulation Use the following (1)-
The test of (3) was performed.

(1) Adhesion Prevention Test for Synthetic Resin Five acrylic plates of the same quality are prepared, one is uncoated, and the remaining 4
A fixed amount of the above sample is applied to each sheet. A fixed amount of melted hot melt adhesive (having ethylene vinyl copolymer as a main component) is applied to these. After the hot melt adhesive was cooled and solidified, the adhesion of the hot melt adhesive to the acrylic plate was examined. Further, the acrylic plate was replaced with an ABS resin plate and a polycarbonate resin plate, and the adhesion was similarly observed.

◯: Good ... Easy to peel off and can be used as an adhesion preventive agent.

Δ: Fair ... It is difficult to peel off and lacks the adhesion preventive power.

X: No addition ... It does not peel off at all and adheres completely.

(2) Adhesion Prevention Test in High Temperature Part In test (1), the acrylic plate was changed to an aluminum plate, and a sample was similarly applied. The aluminum plate is heated to 200 ° C. and maintained at 200 ° C. for 1 hour, and then a fixed amount of solid hot melt adhesive is dropped onto the coated surface in fixed amounts and melted. Furthermore, after leaving it at 200 ° C. for 1 hour, it is further left until it returns to room temperature.
The state of the cold-solidified hot melt adhesive on the aluminum plate and its adhesion to the aluminum plate were investigated. The results are shown in Table 2.

A: Easy to peel off.

◯: Easy to peel off.

Δ: Hard to peel off.

X: Not peeled at all.

In the table, the state of the hot melt adhesive when ◎ ○ is
Since the attached surface is difficult to get wet, it looks like a small ball, whereas when it is ×, the wetness is wide.

(3) Test of persistence of anti-adhesion force In Test (1), the adhesive was peeled off, the hot melt adhesive melted was applied to the same place again, the same test was repeated, and this was repeated. , I checked how many times it will not come off. The results are shown in Table 3.

Further, in the test (2), the sample was applied to an aluminum plate and kept at 200 ° C. for 1 day and 8 hours, and then the adhesive was dropped in the same manner, and it was examined whether or not it peeled off. In regard to the above, the number of days after which a cycle of 200 ° C. and 8 hours was repeated was examined. The results are shown in Table 4.

As is clear from the above results, in the formulation examples 1 and 2 in which both the oil-soluble silicone oil having excellent heat resistance and the water-soluble silicone oil having excellent adhesiveness are blended, the adhesion is caused by the difference in material and the high temperature. It was found that the preventive property is not weakened and the durability is excellent.

Claims (1)

[Claims] 1. An anti-adhesion agent for a hot melt adhesive, comprising an oil-soluble silicone oil and a water-soluble silicone oil dissolved in a chlorofluorocarbon solvent.