JP4269073B2 - Reactive hot melt curable composition and curing method - Google Patents

Description

The present invention is useful for adhesives, pressure-sensitive adhesives, coating agents, sealing agents, etc., is environmentally friendly, has excellent high-speed workability and operability, and has excellent cured physical properties such as heat resistance. It relates to a curing method.

In recent years, curable compositions such as adhesives, pressure-sensitive adhesives, coating agents, and sealing agents are increasingly required to have higher performance, higher functionality, higher productivity, and safety and environmental friendliness. However, in reality, it is difficult to satisfy all of these requirements, and efforts continue to seek the ideal. In order to achieve high performance and high functionality, competition is being held at the level of how to improve productivity and environmental performance. Above all, improvement in productivity is an important factor, and it is important to be able to work at high speed.

Regarding high-speed workability, for example, cyanoacrylate instantaneous adhesives and light (ultraviolet) curable adhesives are prominent as reactive adhesives. However, when cyanoacrylate is bonded to a large area, curing progresses in the middle of the coating process, and the work cannot be performed. Also, when bonding a thick adhesive layer with a gap or the like, the adhesive flows and does not cure. Have the disadvantages. In the light (ultraviolet) curing type, although curing is fast, there is a disadvantage that curing cannot be expected at a portion where light is not transmitted.

A hot melt adhesive is prominent as a hot melt adhesive. The adhesive is fixed by cooling the thermoplastic resin melted by heating. Therefore, the initial adhesiveness is extremely excellent and the workability is good. In addition, the adhesive is ideal because it does not contain solvents and is excellent in terms of environment and safety. However, the greatest drawback of this adhesive is that the heat resistance is essentially inferior because the resin softens and flows above the softening point of the thermoplastic resin as the main component. Therefore, it is not suitable for adhesion of members that require heat resistance.

In order to improve this heat resistance, a reactive hot melt adhesive that crosslinks a thermoplastic resin by a reaction after adhesion application and fixation is prominent. As a typical example, a polyurethane-based reactive hot melt adhesive (hereinafter referred to as moisture) mainly composed of a urethane prepolymer resin having an isocyanate group at the molecular end, using an isocyanate group and water (humidity in the air, etc.) for the crosslinking reaction. Abbreviated as curable polyurethane), for example, disclosed in JP-A-5-17736, JP-A-2001-316654, JP-A-2002-155259, and the like.

However, the moisture-curable polyurethane has the following problems although the heat resistance is improved. That is, since moisture is used for the crosslinking reaction, the reaction is affected by humidity. In addition, low water content materials such as metals and non-polar plastics do not supply sufficient water (adherent water) necessary for the reaction. As a result, in a low humidity and low moisture content material, sufficient crosslinking reaction may not be exhibited, and heat resistance is unstable.

Further, when the adhesive is exposed to moisture, it has a drawback of being cured during storage, or being cured in a coating machine to block the nozzle. Further, since carbon dioxide gas is generated when reacting with moisture, the cured product foams, and there is a problem that the physical properties and appearance are deteriorated. Furthermore, since the thermoplastic polymer which is the main component of the adhesive is produced with an excess of isocyanate, unreacted isocyanate remains in the adhesive. For this reason, when the adhesive is heated and applied, the unreacted isocyanate becomes a vapor, and its vapor toxicity is concerned in terms of environment and safety, and improvement of facilities such as ventilation is necessary.

A cross-linking system that replaces water has also been proposed. For example, JP-A-5-70754 and JP-A-9-31428 disclose a two-component type reactive hot melt adhesive. These are intended to improve the heat resistance by forming a cross-link by reaction between the functional groups contained in the two agents, but it is necessary to mix well under heating in order to carry out the reaction of the functional groups. Etc. had difficulties. Japanese Patent Application Laid-Open No. 2002-212533 discloses a heat-reactive hot melt adhesive. However, in order to obtain a preferable heat resistance, it is necessary to heat at a high temperature of about 200 ° C. or higher after fixing the adhesive.

In the production of the moisture curable polyurethane adhesive, first, an excess diisocyanate is added to the reaction vessel in the presence of dehydration and inert gas in the presence of a bifunctional diol, etc. Accordingly, a solvent, a tackifier and the like are added, and polymerization is carried out for several hours under heating and mixing to produce a polyurethane polymer having an isocyanate group at the terminal. This production takes a long time for the reaction, and handles a highly viscous liquid and a highly viscous liquid. Therefore, it is necessary to take out the reaction liquid, wash the reaction tank, etc., and the workability is poor. Furthermore, in order to use it as an adhesive, it was necessary to fill the melting tank of the coating machine, heat and melt the polymer, and heat the entire coating machine. As a result, the heat load of the adhesive and the coating machine was large.

On the other hand, although high-speed workability as reactive hot melt cannot be obtained, there is another attempt to increase productivity by combining high-speed workability and excellent operability at room temperature. Among them, contact bonding is prominent. Contact adhesion is performed by applying an adhesive on both surfaces of an adherend and applying high adhesive force, that is, tack, which develops after a predetermined open time. There is no need for temporary holding because it exhibits excellent strength immediately after bonding. In addition, since the tack state (high adhesion state, not so-called sticking) is maintained for a while (tack range), it is convenient for correction of a bonding portion in large-area bonding or precision bonding, and operability is extremely good. .

As such a contact adhesive, a solvent-type rubber adhesive is prominent. However, this rubber-based adhesive has problems of toxicity to human body due to solvent, fire and environmental pollution. A rubber emulsion adhesive is also prominent, and this requires a lot of energy to evaporate and remove water, and the evaporation time is long, so high speed workability cannot be expected. Therefore, the emergence of a reactive contact adhesive that does not use a solvent is desired, and research is still ongoing. As this adhesive, a prepolymer having a hydrolyzable silicon group in the molecule is used, and moisture in the air (water) is used in the reaction to cause tackiness by polymerizing and cure one liquid moisture. A curable contact adhesive is prominent. These are described in, for example, Japanese Patent Application Laid-Open No. 3-263478, but this has a problem that it takes a long time to develop tack. Japanese Patent Application Laid-Open No. 2003-27032 reports a urethane resin contact adhesive that has a short time to tack appearance, a large adhesive strength immediately after the tack, and an excellent operability with a long tack range.

However, these moisture-curing types have excellent operability, but have the following problems. That is, although tack development is improved, tack development takes about 5 minutes at room temperature. For example, in production sites where the line speed of the bonding process is fast and high workability is required, it is sufficiently fast. I can not say. In addition, since humidity in the air is used for the reaction, the reaction is affected by the temperature and humidity, so temperature and humidity management is important. In particular, the curing rate is affected by the thickness of the cured product layer. That is, since the surface of the cured product has a sufficient supply amount of air (humidity), curing is fast. However, the inside is not sufficiently supplied with moisture from the surface, so that curing becomes extremely slow, and sufficient tack cannot be obtained, making it difficult to control the tack. Furthermore, in the adhesive design and the cured product design, one of the reaction sources is limited to moisture (water), so that the cured product design is limited. Therefore, it cannot be denied that various designs (for example, high hardness, high strength, etc.) that meet the needs are difficult.

For example, JP-A-2002-275449 also proposes a two-component reaction type (separation coating type) contact adhesive. However, in order to obtain predetermined physical properties, it is necessary to use a high concentration of organic peroxide and reducing agent having a low thermal decomposition temperature. In addition, when the two liquids are bonded separately without being mixed, the operability is improved, but the composition balance may be lost, and there is a concern about the formation of an uncured part and the residual monomer remaining. Therefore, it is not suitable for sealing with a thick cured product layer. As described above, the adhesives and the like conventionally used for improving productivity also have such problems.
JP-A-5-17736 JP 2001-316654 A JP 2002-155259 A JP-A-5-70754 Japanese Patent Laid-Open No. 9-31428 JP 2002-212533 A JP-A-3-263478 JP 2003-27032 A JP 2002-275449 A Unsaturated polyester chemistry [quoted / by Eiichiro Takiyama, polyester resin: issued on August 30, 1973 (Nikkan Kogyo Shimbun)

The present invention overcomes the problems of conventional reactive hot melt adhesives, etc., is environmentally friendly and excellent in high-speed workability and operability, is improved in cured properties such as heat resistance, and can be used for multipurpose applications It is an object to provide a reactive hot melt curable composition and a curing method.

The inventor has intensively studied the problems of conventional curable compositions. As a result, selected from a specific polymer, a specific reactive substance for synthesizing the polymer, a specific cross-linking agent, a specific polymer forming catalyst, a specific cross-linking catalyst, etc., and from a specific composition ratio It has been found that the reactive hot-melt curable composition of the present invention can solve the problems of the conventional curable composition, and the present invention has been completed.

That is, the present invention provides: Reactive hot characterized in that it contains a urethane polymer having a molecular end at the hydroxyl group, a softening temperature of 30 to 200 ° C. and capable of forming a crosslink, and a crosslink catalyst coated with a heat-meltable substance. A melt-curable composition.

2. The reactive hot-melt curable composition according to claim 1, further comprising an acrylate or methacrylate having a boiling point of 180 ° C. or higher as a crosslinking agent .

3. A curing method comprising applying the reactive hot-melt curable composition according to claim 1 or 2 and promoting post-curing by heating after fixing.

Terms used in this application will be described.
The “fast fixing-post-curing type” of the “fast fixing-post-curing type curable composition” refers to so-called temporary fixing with initial fast fixing and strong crosslinking with subsequent curing. As used herein, “adhesion” refers to a certain kind of adhesive force accompanying a change from a so-called liquid to a solid, and this includes so-called “adhesion” of the boundary region between the liquid and the solid. “Crosslinking” usually refers to chemical crosslinking, but also includes physical crosslinking (where heat resistance is improved). “Tack” means the same meaning as “high adhesion”. The “polymer” of the present invention refers to a thermoplastic polymer, and includes a prepolymer having a relatively low molecular weight. In addition, a polymer (such as an initial polymer) that retains fluidity even if it is a thermosetting polymer is included in the “polymer”. Further, “two agents” means “two liquids”, and “agents” mean “liquids”, but include those that are easily liquefied by heating even if they are solid at room temperature.

From the above results, new problems that overcome the problems of conventional reactive hot melt adhesives, are environmentally friendly, have high-speed workability and operability, improve cured properties such as heat resistance, and can be used for multipurpose applications Reactive hot-melt curable compositions and curing methods were obtained. As a result, the present invention has a great industrial advantage.

The present invention will be described in detail below. The main object of the present invention is to provide high-speed workability, excellent operability, and excellent characteristics of a reactive hot melt in order to obtain high productivity.

The present invention consists of the following matters alone or in combination. 1. Fast fixation (initial fixation) is performed using a polymer having a relatively low molecular weight, and is post-cured (crosslinked) to change to a crosslinked body. This improves physical properties such as heat resistance. 2. The fast fixing means is fixed by cooling the polymer melted by heating (hereinafter referred to as a melt-type polymer). Also, the two agents are reacted to synthesize a highly adhesive polymer in an extremely short time and fix with this adhesive force (hereinafter referred to as a synthetic polymer). Either method is used. 3. The post-curing means is centered on chemical crosslinking, mainly radical crosslinking. 4). Both the melt-type polymer and the synthetic-type polymer are obtained by changing the softening temperature of the polymer by the same technique and by controlling the molecular weight and structure of the polymer. As a guide, when the softening temperature is about 35 ° C. or higher, it is used as a molten mold, and when it is 35 ° C. or lower (room temperature and high adhesion), it is used as a synthetic mold.

5). When the softening temperature of the polymer is 35 ° C. or higher, it is used as a reactive hot melt composition, and when it is 35 ° C. or lower, it is used as a contact-type composition. 6). The polymer structure is controlled by controlling the hard segment and the soft segment constituting the polymer. 7. Further, the cured product (crosslinked product) is controlled by controlling the polymer and the crosslinking agent. 8). For rate control, polymer synthesis and tack development time are controlled by a synthesis catalyst. The tack range and post-crosslinking are controlled by a crosslinking catalyst. In addition, heating is used to shorten post-curing. 9. A coating technique for coating a catalyst or the like is used for improving heat stability and storage stability and for one-liquefaction technique. 10. Improves uniform and deep curability of cured products. 11. As a new economical synthesis method for polymer synthesis, synthesis is performed directly in a coating machine.

The present invention provides the curable composition of the present invention. A reactive hot-melt curable composition comprising a polymer of the present invention and / or a reactive substance for synthesizing the polymer (one reactive substance and the other reactive substance) as a main component, and further 2 An agent-reactive hot melt curable composition is provided. The composition is useful for adhesives, pressure-sensitive adhesives, coating agents, sealing agents, paints and the like. And the hot-melt curable composition of this invention is an easy environment type, and its heat resistance is favorable. Also, it can be either one-component type or two-component type. In the one-pack type, the operability is further improved, and in the two-part type, the thermal stability and the storage stability are further improved.

The polymer used as the main component of the curable composition of the present invention desirably softens and flows at a relatively low heating temperature. Therefore, the softening flow temperature of the polymer is highly sticky at ordinary temperature or a temperature range of about 30 ° C to 200 ° C, more preferably a temperature range of about 40 ° C to 120 ° C. Those having a so-called highly adhesive state at a softening temperature of about 30 ° C. or lower to around room temperature are also useful. However, when the fluidization has further progressed from the highly adhesive state at normal temperature, the initial fixing property referred to in the present invention is lowered, and the function as the composition of the present invention may not be performed. Further, when the temperature is 200 ° C. or higher, a high temperature is required to fluidize the polymer, and the polymer may be deteriorated. Also, in the presence of a crosslinking agent, the thermal stability may be extremely decreased. is there. Furthermore, it is desirable that the polymer of the present invention can be crosslinked at 140 ° C. or lower, preferably at room temperature, in the presence of a curable catalyst or the like. Any polymer that satisfies such conditions can be used in the present invention.

As examples, the following polymers may be used alone or modified. These are polyaddition / polycondensation type polymers such as polyurethane, polyamide, polyester, epoxy, silicone, etc., and addition polymerization type polymers such as polyolefin, ethylene vinyl acetate copolymer, and styrene-butadiene-styrene (SBS). , Thermoplastic elastomers such as styrene-isoprene-styrene (SIS) and hydrogenated products thereof. Moreover, what has a reactive group in the molecule | numerators, such as liquid rubber, a reactive adhesive substance, etc., dicyclopentadiene resin, etc. can be mentioned. However, it is not limited to these.

It is desirable that a more preferable polymer be easily crosslinked in the presence of a promoter and also a polymerization catalyst comprising a polymerization initiator. More preferably, it is desirable that the accelerator alone be crosslinked. Therefore, as the polymer, those containing an ethylenically saturated group in the molecule or those generating radicals in the polymer by a catalyst or the like are used. The position of the unsaturated group may be present either at the molecular end or inside the molecule. The polymer can also be used as a mixture of a polymer having the unsaturated group in the polymer molecule and a polymer having no unsaturated group.

A preferred polymer is polyurethane. Polyurethane has a high reaction rate, no reaction by-products, can be easily synthesized, and various molecular weights and structures can be selected by appropriately selecting the number of equivalents of reactants, the number of functional groups, and the skeletal structure. It is very convenient to obtain a composition suitable for multi-purpose use. Furthermore, polyurethane is useful in obtaining a thermoplastic elastomer or a highly adhesive body excellent in heat resistance by controlling the hard segment and soft segment constituting the polyurethane main chain.

Moreover, as a reactive substance for this polymer synthesis | combination, the monomer and / or prepolymer which are used for synthesize | combining a linear polymer are preferable, and a liquid is preferable at normal temperature. In addition, any substance that forms a polymer can be used. For example, if tack can be stably obtained, a means for expressing tack by chemical bonds, ionic bonds, hydrogen bonds, etc., and reactive substances used for tack formation are polyaddition type substances, addition polymerization type substances, etc. Any of these may be used. One reactive substance in the present invention refers to a functional monomer and / or prepolymer having a functional group that reacts with the other functional group and is used in the synthesis of the polymer, and the other reactive substance is It refers to a functional monomer and / or prepolymer having a functional group that is used in the polymer synthesis and reacts with one functional group to give a polymer.

For example, functional monomers and / or prepolymers used for synthesizing polyaddition / polycondensation polymers such as polyurethane, polyamide, polyester, epoxy, and silicone are useful. Other reactive substances include addition polymerization type, ring-opening polymerization type monomers and / or prepolymers, coupling agents utilizing a reaction between functional groups, metal cation species and organic acid anion species, etc. Etc. are also effective. However, it is not limited to these. On the other hand, the cured product obtained by post-curing preferably has a thermally irreversible chemical bond. The cured product can be formed by radical crosslinking or reaction between functional groups, but radical crosslinking is desirable.

One of the preferable reactive substances is a functional monomer and / or prepolymer for forming polyurethane, and a functional monomer and / or prepolymer having an isocyanate group (NCO group). These include, for example, aromatic diisocyanates such as diphenylmethane 4, '4 diisocyanate (MDI) and derivatives of MDI (including prepolymers of MDI and modified MDI), castor oil modified MDI, TDI derivatives (prepolymer of TDI), , 6-hexamethylene diisocyanate and other aliphatic diisocyanates, or isophorone diisocyanate, xylidene diisocyanate, hydrogenated xylidene diisocyanate and other alicyclic diisocyanates, but are not limited to these and are known in urethane chemistry Things can be used.

Among these, MDI derivatives which are advantageous in terms of safety because of a fast curing speed, excellent heat resistance, and low vapor pressure among isocyanates are suitable. As the MDI derivative, those having an NCO group equivalent of about 125 to 3000 and an average number of functional groups of NCO groups of about 2 to 3 are suitable. If the equivalent weight exceeds 3000, curing tends to be slow and the viscosity tends to increase. On the other hand, if the average number of functional groups is less than 2, it is difficult to form a polymer.

The other reactive substance of the preferable reactive substance is a functional monomer and / or prepolymer having an organic active hydrogen group. Examples of the organic active hydrogen group include —OH group, —COOH group, —NH 2 group, —NHR group, —SH group, and the like. Among these, —OH group (hydroxyl group) is suitable in terms of excellent reactivity with isocyanate (NCO) group, safety (low toxicity, low odor), and low price. Examples of functional monomers and / or prepolymers in which the organic active hydrogen group is —OH group include, for example, polyether polyol, polyester polyol, castor oil, castor oil-modified polyol, terminal hydroxyl group-stopped liquid polybutadiene and its hydrogenated product, and terminal hydroxyl group terminated Examples thereof include liquid polyisoprene and hydrogenated products thereof, and terminal hydroxylated modified silicone oils. Moreover, low molecular weight diols such as ethylene glycol, propylene glycol, triethylene glycol, and polyethylene glycol, and low molecular weight triols such as glycerin are used as chain extenders. However, it is not limited to these, The well-known thing used by urethane chemistry can be used.

Among these, preferable monomers and / or prepolymers are polyols having an —OH group equivalent in the range of about 31 to 10,000 and an average functional group number of about 2 to 3, and a diol having an average functional group number of 2 is particularly suitable. The reason is that when the equivalent exceeds 10,000, curing tends to be slow. In addition, the viscosity increases and the operability decreases. Further, if the average number of functional groups exceeds 3, the formed polymer may be crosslinked. On the other hand, when the average number of functional groups is less than 2, synthesis of the polymer becomes difficult.

Furthermore, a reactive substance having an ethylenically unsaturated group in the molecule is suitable as the functional monomer and / or prepolymer for forming polyurethane. The reason is that the substance itself can both form a linear polyurethane and form a crosslink. Moreover, it is because it is easy to form a bridge | crosslinking with the monomer and oligomer which have an ethylenically unsaturated group. Examples of the reactive substance having an unsaturated group in the molecule include liquid isoprene and liquid polybutadiene terminated with hydroxyl groups at both terminals, and both 1.4-type polybutadiene and 1.2-type polybutadiene are useful. In addition, substances having an ethylenically unsaturated group such as an active hydrogen group and an acrylic (methacrylic) group in the molecule, and substances having an ethylenically unsaturated group such as an isocyanate group and an acrylic (methacrylic) group in the molecule are also included. Useful. However, it is not limited to these.

Furthermore, the equivalent standard is important for obtaining the polymer of the present invention. The equivalent standard (NCO group / OH group equivalent ratio) for polyurethane synthesis is in the range of 3.5 / 1 to 1 / 3.5. If the corresponding ratio is 3.5 / 1 or more and 1 / 3.5 or less, the molecular weight does not increase in any case, so that the molecular weight necessary for initial fixation or tack cannot be obtained. A suitable applicable amount ratio is suitably in the range of 2.5 / 1 to 1.3 / 1, or 1 / 1.1-1 to 2.5. The polyurethane formed in this range has a softening temperature of approximately 100 ° C. or lower, and a solid or preferable tack can be obtained at room temperature. And both a melt type polymer and a synthetic type polymer are obtained.

Furthermore, in this range, the molecular weight can be easily adjusted and the reaction can be completed in a short time. As a result, a melt polymer having a constant melt viscosity can be obtained in a very short time. Further, in the synthetic polymer, tack can be expressed in a short time. Further, the tack can be kept stable until the crosslinking reaction is started. On the other hand, when the equivalent ratio is in the range of 1.3 / 1 to 1 / 1.1, the molecular weight increases, and the molecular weight changes greatly even if the equivalent ratio slightly varies. As a result, it becomes difficult to control the melt viscosity of the molten polymer or to control the tack of the synthetic polymer.

When the ratio is within the range of 2.5 / 1 to 1.3 / 1, the synthesized polyurethane forms a relatively low molecular weight polymer in which most of the molecular end groups are terminated with NCO groups. The This is useful for conventional moisture curable polyurethanes and the like. However, it becomes easy to foam. On the other hand, when the amount ratio is 1/1/1 to 1 / 2.5, a polymer having a relatively small molecular weight in which most of the molecular end groups are terminated with OH groups is formed.

An even more preferable applicable amount ratio is 1 / 1.1-1 / 2. The polyurethane formed in this range has an OH group at the molecular end and almost no NCO group. Therefore, it is extremely useful because it can eliminate conventional problems such as polyurethane foaming, solidification by moisture during storage, and isocyanate vapor toxicity due to residual unreacted isocyanate, making it easy to operate and environmentally friendly. .

In the composition of the present invention, a crosslinking agent is used in order to efficiently perform the crosslinking reaction. The crosslinking agent used is an addition polymerization type monomer and / or oligomer having an unsaturated group such as methacrylate or acrylate. In addition, all of those capable of forming a crosslink such as a crosslinking agent such as a coupling agent utilizing a reaction between functional groups, a functional monomer having 3 or more functionalities, and / or a prepolymer can be exemplified. Among these, addition polymerization monomers such as acrylates and methacrylates, oligomers, and prepolymers are preferable. Preferred acrylates and methacrylates have a boiling point of about 180 ° C. or higher at normal pressure, more preferably about 200 ° C. or higher, or an extremely low vapor pressure at room temperature, and a vapor pressure of 0.1 Torr at room temperature, more preferably 0.01 Torr, more preferably 0.001 Torr or less. That is, it is substantially non-volatile and odorless. By using these monomers, the inhalation of vapor into the human body is reduced and the safety is further improved, and at the same time, the environmental pollution is improved.

Any acrylate or methacrylate may be used as long as the conditions described above are satisfied. For example, urethane acrylate, urethane methacrylate, polyester acrylate, polyester methacrylate, epoxy acrylate, epoxy methacrylate, mono-, g-, tri-acrylate, mono-, di-, tri-methacrylate, trimethylolpropane trimethacrylate, etc. Those used in chemistry are mentioned. In addition to those that exhibit radical polymerizability other than acrylate and methacrylate, for example, dry oil such as linseed oil is also useful. However, it is not limited to the substance illustrated here.

The addition amount of acrylate and methacrylate used here is 1 to 50 with respect to the total amount including the polymer or the reactive substance for synthesizing the polymer (one reactive substance and the other reactive substance). It can be used in the range of% by weight. When the addition amount exceeds 50% by weight, the polymer containing the cross-linking agent (both in the melt type polymer and the synthetic type polymer) is easily fluidized. Therefore, fixation by cooling cannot be obtained in the melt type polymer, and it is difficult to express tack in the synthetic type polymer. If the amount added is less than 1% by weight, the amount of cross-linking is reduced and the effect as a cross-linking agent is hardly expected.

As the catalyst used for polymer synthesis of the composition of the present invention, any catalyst that promotes the formation of a polymer can be used, and among them, a known polyurethane synthesis catalyst is useful. Among them, for example, tertiary amine catalysts such as triethylenediamine, organotin catalysts such as dibutyltin dilaurate as metal catalysts, octenoates such as iron, chromium, nickel and zinc, or naphthenates, acetylacetone Complex compounds and the like. The synthesis time of the melt-type polymer under heating and the tack development time of the synthesis-type polymer at room temperature can be controlled by the addition amount of these catalysts.

The addition amount of these catalysts is 0 with respect to 100 parts by weight of the total amount of all the reactive substances including the polymer or the reactive substance for synthesizing the polymer (one reactive substance and the other reactive substance) and the crosslinking agent. .01 to 5 parts by weight. In the synthesis of a synthetic polymer, the addition amount of 5 parts by weight can be cured sufficiently fast, and tack can be developed within 30 seconds at room temperature, and a curing rate close to that of an instantaneous adhesive can be obtained, so no further use is required. . Moreover, if it is 0.01 parts or less, a high curing rate cannot be obtained. A more preferable addition amount is 0.1 to 3 parts by weight, and an even more preferable addition amount is 0.3 to 1.5 parts by weight. Within this range, tack can be developed within 1 minute at room temperature, and high-speed workability is possible. Such a high-speed workability cannot be expected with the conventional contact type. Further, in the synthesis of a melt-type polymer under heating, the reaction rate is increased by heating, and ultrafast synthesis of several seconds to several tens of seconds is possible. This is not very desirable in the production of conventional moisture curable polyurethanes.

As the crosslinking catalyst of the composition of the present invention, a polymerization catalyst such as a metal soap alone or a polymerization catalyst comprising a polymerization initiator and a polymerization accelerator is useful. By adjusting the combination of these catalysts or the amount of the catalyst, it is possible to adjust the crosslinking start time of the synthetic polymer at room temperature, that is, the tack range, and also to control the post-curing, that is, the crosslinking time. The tack range can be adjusted in several minutes to several hours, and the post-curing can be adjusted in several tens minutes to several hours, and crosslinking can be arbitrarily controlled at a sufficiently high speed. Moreover, the post-curing time can be further shortened by heating or reheating these post-curing. These can also be carried out similarly in the post-curing of the molten polymer.

As the catalyst used here, for example, a known catalyst in unsaturated polyester chemistry [cited by Eiichiro Takiyama, polyester resin: issued on August 30, 1973 (Nikkan Kogyo Shimbun)] can be applied. Among them, metal soaps such as cobalt naphthenate, manganese naphthenate, and copper naphthenate are particularly useful as polymerization accelerators. As the polymerization initiator, organic peroxides such as cumene hydroperoxide (CHP) and methyl ethyl ketone peroxide having a high thermal decomposition temperature are useful. When coexisting with isocyanate, peroxyesters such as t-butyl peroxylaurate are useful, but are not limited thereto.

The amount of the polymerization accelerator used here is 0.002 to 5 parts by weight with respect to 100 parts by weight of the total amount of all the reactive substances. When the addition amount is 5 parts by weight, sufficiently fast curing can be obtained, so that it is not necessary to use any more. On the contrary, if it is less than 0.002 parts by weight, a high speed cannot be obtained. A preferred amount is 0.01 to 3 parts by weight, and a more preferred amount is 0.1 to 2 parts by weight. The amount of the polymerization initiator is 0.005 to 5 parts by weight with respect to 100 parts by weight as a whole. A preferred amount is 0.01 to 3 parts by weight, and a more preferred amount is 0.1 to 2 parts by weight. These polymerization accelerators and polymerization initiators can accelerate the crosslinking reaction with a small amount of use. As a result, the amount of heavy metal and peroxide used can be reduced, leading to improvements in the environment and safety.

The composition of the present invention normally uses both a polymer synthesis catalyst and a crosslinking catalyst, except when the synthesis of the polymer is carried out quickly, for example, without using catalyst as an isocyanate and active hydride. . Therefore, the combination of both catalysts is important to maintain good catalyst stability. When both catalysts are used, the stability is significantly impaired by the reaction between the catalysts or the reaction between the catalyst and another reactive substance (polymerizable monomer). For example, when a polymerization initiator and an accelerator coexist, a redox reaction occurs rapidly. Therefore, it is necessary to separate both into a first agent and a second agent. For example, since the isocyanate contained in the first agent easily reacts with the active hydride, the active hydride needs to be separated into the second agent. Moreover, the polymerizable monomer used as the crosslinking agent is easily polymerized by the generated radical. Therefore, radical generation needs to be suppressed during storage.

Regarding the maintenance of storage stability at room temperature, in the presence of the isocyanate of the first agent (isocyanate side), it is possible to have a metal soap alone or a combination of metal soap and organotin. However, the presence of the polymerization initiator (hydroperoxide) acts in the direction of decreasing the stability, and the coexistence of organotin significantly decreases the stability. On the other hand, in the presence of the second agent (diol side) diol, the stability is not lowered even if a polymerization initiator (hydroperoxide) and organotin are allowed to coexist. If two agents are used in this manner, both the polymer synthesis catalyst and the crosslinking catalyst can be stably present. However, it is not limited to these.

Furthermore, in order to further improve the stability in the presence of the catalyst, a method of coating the surface of the catalyst or the like is effective. The polymer of the present invention and / or the polymerizable substance that is also a cross-linking agent are promoted for cross-linking and polymerization by air (oxygen) in the presence of a polymerization accelerator such as metal soap. It is further promoted under heating. Addition of a polymerization inhibitor is effective for improving the stability. However, the addition of a polymerization inhibitor may hinder curing when the addition amount is increased. On the other hand, the method of coating the polymerization accelerator with an easily heat-meltable substance or the like exhibits excellent stability and is not inhibited from curing.

The term “coating” as used herein includes not only coating with a coating material and microencapsulation, but also dispersing and encapsulating the material to be coated, and means that the material to be coated is shielded from air. . The easily meltable substance refers to a substance that is easily melted by heating. It also includes elution, dissociation, sustained release, etc. of substances coated with heat. They may be any organic, inorganic, natural or synthetic substances that are inert to the material to be coated, are solid at room temperature, and can be easily melted by heating. More preferably, it is a thermoplastic substance exhibiting air barrier properties and having a relatively low molecular weight. The activity is expressed when the material melts and the coated material is eluted by heating near or above the melting temperature of the easily meltable material.

. They include, for example, wax and rosin as natural products, low-molecular polyethylene, low-molecular polyolefin, low-molecular polystyrene, low-molecular polyester, petroleum resin, etc. as synthetic products, and water-soluble waxes such as polyethylene glycols. It is done. However, it is not limited to these. Among these, waxes that can be used in a wide range of melting temperatures and have a high melting rate are useful. Preferred waxes have a melting point of 40-180 ° C, more preferably a wax having a melting point of about 40-130. More preferably, it is about 45 to 115 ° C.

The substance to be coated here is selected from accelerators, polymerization initiators and polymerizable substances. Accelerators need to be coated and used. A polymerization initiator and a polymerizable substance are coated as necessary. The coating may be any one of a coating of an accelerator alone, a coating of a polymerization initiator alone, a coating of a mixture of an accelerator and a polymerizable substance, and a coating of a polymerization initiator and a polymerizable substance. Moreover, you may use 1 or more types of these coating bodies. Thus, by coating, even if an accelerator and a polymerization initiator coexist, direct contact of both can be avoided and both can be stably coexisted.

As a result, both can coexist and can be used as a one-drug type, or separated and used as a two-drug type. The one-part type is useful for obtaining a reactive hot-melt curable composition having excellent operability. In the one-agent type, any of accelerator coating (single system), accelerator coating, and polymerization initiator coating (combination system) can be used. The single system is an oxidation polymerization system, and the combined system is a redox polymerization system. The former uses oxygen in the air for curing, and is effective for a thin cured product layer that can be sufficiently supplied with air. When the cured product layer is thick, the inside of the cured product is suppressed from being supplied with air, so that the deep curability may be deteriorated. On the other hand, the latter (redox system) does not have such a worry. In addition, as an advantage of coating, there is an effect in suppressing vapor generation of a substance to be coated during heating. In addition, when handling the product, contact with the skin can be prevented, which is effective in improving the environment and safety.

As for the coating method, either the material to be coated is directly mixed with the easily meltable material, or the material to be coated is mixed with a small amount of a nucleating agent such as inorganic powder and then mixed with the easily meltable material. The method may be used. The mixture is mixed at a temperature equal to or higher than the melting point of the easily heat-meltable material, homogenized, cooled and solidified, and pulverized before use. In addition, known microencapsulation methods and the like can also be applied, but are not limited thereto.

The weight ratio of the material to be coated and the easily meltable material is 1 to 50% by weight for the material to be coated and 99 to 50% by weight for the easily meltable material. A more preferred weight ratio is 3 to 30% by weight of the material to be coated, 97 to 70% of the easily meltable material, and an even more preferred weight ratio is 5 to 20% by weight of the material to be coated, easily meltable The material is 95-80%. If the amount of the material to be coated is 1% or less, the amount of the easily heat-meltable material used is increased, which may be impractical. Moreover, if it is 50% or more, there is a possibility that it is not partially covered.

Addition of a polymerization inhibitor is useful as long as it does not interfere with curing. A known radical polymerization inhibitor can be used. For example, hydroquinone monomethyl ether, hydroquinone and the like can be mentioned, but not limited thereto. A suitable inhibitor amount used is 0.001 to 0.2 parts by weight with respect to 100 parts by weight of the total amount of all reactive substances. A preferred inhibitor amount is 0.001 to 0.05 parts by weight.

The composition of this invention can mix | blend various additives as needed. As examples of additives, liquid tackifiers such as terpene resins, rosin derivatives and dicyclopentadiene resins, particularly liquid tackifiers having reactive unsaturated groups are useful. Plasticizers such as fumarate ester, adipic acid ester and phosphate ester, and reactive plasticizers. Waxes such as montan wax and polyethylene wax. Inorganic fillers such as calcium carbonate, calcium sulfate, magnesium silicate, magnesium carbonate, alumina, quartz powder, silica, hemihydrate gypsum, zeolite, cement and talc. Furthermore, various metal powders, various organic powders, colorants, heat stabilizers, antioxidants, light stabilizers and the like can be added. However, it is not limited to these. In addition, polymers can be added as long as fluidity is not hindered.

In the curable composition of the present invention, the reactive substance forming the polymer, the crosslinking agent, and the reaction conditions can be appropriately selected from many options. For example, with regard to polymers, the sol-like adhesive, gel-like adhesive, gel-like solid, rubbery, flexible and hard polymers can be freely prepared by controlling the structure of the hard segment and soft segment. it can. Based on these polymers, it can be modified into many cured bodies (crosslinked bodies) using crosslinking agents having various structures. As a result, by changing the structural properties (skeletal structure, functional group, number of functional groups, polarity, molecular weight) of the reactive substance and cross-linking agent used, in addition to strength, low temperature to high temperature thermal characteristics, water resistance, It is easy to change various properties such as chemical resistance, gas barrier properties, and electrical / optical properties. As a result, it is suitable for obtaining a material suitable for multipurpose use.

The present invention further provides a curing method useful for the polymers and compositions of the present invention. Provided is a curing method in which the curable composition of the present invention is used to accelerate curing by heating after application and fixation of the composition. In more detail, the said fixed thing of this invention curable composition shows the outstanding adhesion holding characteristic with respect to a heating. Furthermore, there is a characteristic that the curing becomes very fast by heating. Therefore, the fixed object can be accelerated by heating without dripping (flowing) of the fixed object. As a result, quick post-curing heating is possible, and the post-curing time can be greatly shortened. Furthermore, a hardened | cured material can be made into a firmer hardening body.

In particular, a method in which the coating is used and cured at or near the melting temperature of the easily meltable material of the coating is useful. If a covering is used, the polymerization initiator and the polymerization accelerator can coexist at a temperature lower than the melting temperature of the heat-fusible substance, and after the melting temperature, the polymerization initiator and the polymerization accelerator cause a rapid reaction. Curing can be done instantaneously. By using this curing method, the efficiency of the bonding process and the like can be greatly improved. This method is particularly useful for bonding that requires high workability, such as continuous bonding of films, sheets, plate-like plastic suprastics, plastic soot metal films, sheets, plate-like laminates, and the like. Furthermore, the present curing method is particularly useful for the method of accelerating the curing of the curable composition in addition to the present invention.

(Examples) The present invention will be described below with reference to experimental examples. For each substance used in this test, commercially available materials and reagents were used except for the following synthesis examples. Moreover, the evaluation test etc. were based on the following method.

[Synthesis of Polymer] (Synthesis Example 1) 20 mg equivalent of diphenylmethane-4,4-diisocyanate (manufactured by Wako Pure Chemicals, MDI), terminal hydroxyl group-stopped liquid 1,2 polybutadiene (manufactured by Nippon Soda, G1000: bifunctional, equivalent number) 750) 26 milligram equivalents were collected in a heated 100 ml stainless steel flat bottom vessel equipped with a stir bar. When the container was sealed with a polyethylene film to prevent the intrusion of air and moisture and stirred for 30 minutes on a hot plate maintained at an external temperature of 100 ° C., the viscosity did not increase. Stirring was further continued for 30 minutes to obtain a highly viscous liquid. The viscous liquid was transferred to an aluminum foil container and cooled to room temperature to solidify to obtain a light yellow transparent polymer. The softening temperature of the polymer was about 70 ° C. The polymer was allowed to stand in air at room temperature for 7 days, but the polymer did not foam.

(Synthesis Example 2) URICN 2023 (manufactured by Ito Oil, castor oil-modified MDI, bifunctional, equivalent number 260): 20 milligram equivalent, G1000: According to the method of Synthesis Example 1 except that 26 milligram equivalent was used. When cooled to room temperature, a pale yellow transparent polymer that solidified but showed some tackiness was obtained. The softening temperature of the polymer was about 45 ° C. The polymer was allowed to stand in air at room temperature for 7 days, but the polymer did not foam.

(Synthesis Example 3) URICN 2023: 20 milligram equivalent, P-700 (manufactured by Asahi Denka, polyether diol, bifunctional, equivalent number 350): The method of Synthesis Example 1 was used except that 26 milligram equivalent was used. A pale yellow transparent polymer which solidified upon cooling to room temperature but showed tackiness was obtained. The softening temperature of the polymer was about 40 ° C. The polymer was allowed to stand in air at room temperature for 7 days, but the polymer did not foam.

(Synthesis Example 4) URICN 2023: 20 milligram equivalent, terminal hydroxyl group-stopped liquid 1,4 polyisoprene (Idemitsu Petrochemical, ip: bifunctional, equivalent number 1220) Except for using 26 milligram equivalent, the method of Synthesis Example 1 was used. It was. A pale yellow transparent polymer which solidified upon cooling to room temperature but showed tackiness was obtained. The softening temperature of the polymer was about 40 ° C. The polymer was allowed to stand in air at room temperature for 7 days, but the polymer did not foam.

(Synthesis Example 5) The method of Synthesis Example 1 was used except that URICN 2023: 20 milligram equivalent, G1000: 13 milligram equivalent, and P-700: 13 milligram equivalent were used. When cooled to room temperature, it solidified, but a light yellow transparent polymer showing slight tackiness was obtained. The softening temperature of the polymer was about 40 ° C. The polymer was allowed to stand in air at room temperature for 7 days, but the polymer did not foam.

(Synthesis Example 6) The method of Synthesis Example 1 was used except that URICN2023: 26 milligram equivalent and G1000: 20 milligram equivalent were used. Upon cooling to room temperature, it solidified to obtain a light yellow transparent polymer. The softening temperature of the polymer was about 75 ° C. When the polymer was allowed to stand in air at room temperature for 7 days, the polymer foamed slightly.

(Synthesis example 7) NCO / OH equivalent ratio, NCO excess system (moisture curing type similar compounding system): MDI: 50 milligram equivalent, triethylene glycol (manufactured by Wako Pure Chemical Industries): 10 milligram equivalent, P-700: 10 milligram equivalent According to the method of Synthesis Example 1, except that was used. A pale yellow transparent highly viscous liquid was obtained. Solidified upon cooling to room temperature. The softening temperature of the polymer was about 55 ° C. When the polymer was allowed to stand in air at room temperature for 7 days, the polymer foamed significantly.

[Synthesis of terminal NCO type liquid prepolymer]: (Synthesis Example A) MDI: 15 milligram equivalent, terminal hydroxylated liquid polybutadiene (Idemitsu Petrochemical, R45HT: OH group content 0.83 mol / kg) 5 milligram equivalent The sample was taken into a heated 30 ml sample tube equipped with a stir bar. The sample tube is sealed with a polyethylene film to block intrusion of air and moisture, and when stirred for 40 minutes on an aluminum plate (thickness 10 mm) maintained at an external temperature of 100 ° C., the viscosity does not increase, and stirring is continued for 30 minutes to flow A liquid was obtained. This fluid was cooled to room temperature together with the sample tube to obtain a pale yellow transparent highly viscous liquid. The average number of equivalents (calculated value) of the liquid was about 800.

(Synthesis Example B) MDI: 7.5 milligram equivalent, polyether diol (Asahi Glass, Exenol 4010: bifunctional, equivalent number 4800) 2.5 milligram equivalent was used, except that the external temperature was 115 ° C. According to the method of Example A. Fluidized at room temperature to obtain a cloudy liquid. The average equivalent number (calculated value) of the liquid was about 2500.

[Preparation of coated body] (Coated body 1) 0.1 gram of cobalt naphthenate (manufactured by Wako Pure Chemical Industries, Ltd.) was added to 0.3 gram of powdered silica (SBY-61 manufactured by Tosoh Silica), and room temperature in a 50 ml beaker After mixing with 1 gram of wax (FNP115 manufactured by Nippon Seiki: melting point 115 ° C.), the mixture was further melted and mixed at a temperature of 120 ° C. on a heated aluminum plate (thickness 5 mm) to obtain a uniform solution. A cooled solidified body was obtained. The solidified body was pulverized to obtain a coated body 1.

(Coatings 2-9) Using the compounding ingredients shown in Table 3, coatings 2-9 were prepared by the method of coating 1. Table 3 shows the prepared coatings. The following reagents were used for the preparation of the covering.
Wax: Nippon Seiki HNP9: melting point 75 ° C.
Petroleum resin: QUINTON 1500 made by Nippon Zeon, softening temperature 100 ° C.
Ester gum: Superester A-75 manufactured by Arakawa Chemical Co., Ltd. Softening temperature 75 ° C.
-Cumene hydroperoxide: Wako Pure Chemicals.
Trimethylolpropane trimethacrylate: Light ester TMP manufactured by Kyoeisha Chemical.

[Explanation of test method]: (Measurement of softening temperature of polymer): Heated aluminum plate (thickness) on a hot plate using a small piece of polymer test agent (thickness of about 0.5 mm, 5 mm square) 5 mm, 100 mm square) was heated at a constant rate (heating rate increased at 10 ° C. per minute), and the temperature at which the polymer started to soften and flow was measured. As an indicator of fluidization temperature, the temperature at which stringing occurred when the needle was brought into contact with the polymer surface and pulled up was used.

(Measurement of heat resistance) A small piece of test agent (thickness of about 0.5 mm, 5 mm square) is cut with a cutter knife, and the heated aluminum plate on the hot plate is heated at a constant rate (heating rate is increased to 10 ° C per minute) And the melting state of the acute angle surface of the small piece cut edge was observed with a magnifying glass, and the temperature at which the piece was melted (the acute angle cut edge collapsed by melting) was measured.

(Fixability test) About 0.2 to 0.5 g of a test agent is melted at a predetermined heating temperature with a heated aluminum plate, stirred and fluidized for about 10 seconds, the fluid is quickly scraped, and a polypropylene having a thickness of 1 mm. (PP) was transferred onto the sheet (room temperature), crimping sandwiched between PP film having a thickness of 0.3 mm was peeled film was held for about 0.5 minutes. Judgment: ○ The fluidized liquid solidified at room temperature, and the film was peeled off at the interface or was highly tacky. X The fluid is flowing and the film is easily peeled off.

((After) Curability Test) (A) In the case of a melt polymerization system: A test piece was prepared in the same manner as in the adhesion test. The film was peeled off, cured for a predetermined time at room temperature and in an air atmosphere, and the heat resistance measurement was performed. As the curing (crosslinking) progressed, the heat resistance increased and the curability was evaluated. (B) In the case of a synthetic polymer system: As the test agent, the test agent used in the tack development test was cured for a predetermined time at room temperature and in an air atmosphere, and the above heat resistance measurement was performed. As the curing (crosslinking) progressed, the heat resistance increased and the curability was evaluated.

(Storage stability test) A test agent was melt-mixed at a predetermined temperature (below the melting temperature of a readily meltable substance) on a heated aluminum plate to prepare a sheet having a thickness of about 0.5 mm on a PP film. The sheet was allowed to stand at room temperature in air for a predetermined time, and the heat resistance of the sheet was measured to evaluate the stability. Judgment: ○ Good heat resistance temperature does not change. X If the stability deteriorates, curing (crosslinking) proceeds and the heat resistant temperature increases.

(Thermal stability test) (A) Measurement of gelation time: In order to evaluate the flow stability during heating, about 0.2 g of the test agent was taken on a heated aluminum plate, and a ferrite magnet having a smooth surface ( 4 mm thick and 10 mm in diameter) and melted so that air does not enter the aluminum / ferrite interface, and the magnet was repeatedly moved by hand for about 1 to 2 seconds at intervals of about 15 seconds. The time during which the magnet was difficult to move due to the gelation of the melt was measured (unit of time is (minutes)) . (B) Measurement of gelation temperature: Instead of the constant temperature and gelation time of (A), the temperature was raised from room temperature at a constant rate (10 ° C./min), and the gelation temperature of the melt was measured. The measurement was performed in accordance with (A) and the temperature at which the magnet was difficult to move.

(Tack expression time) Using the first agent and the second agent having the formulation shown in Table 7 , both agents were mixed on a 1.5 mm thick polyethylene sheet (300 mm × 200 mm) at room temperature and spread thinly. The time during which tack was developed by the reaction of the two liquids was examined. Tack is manifested by the tack that develops after quickly pressing 10mm square (adhesion surface) x 30mm length of mild steel (weight 23.5g) to the mixed solution, then quickly standing the sheet vertically and keeping the mild steel level. The time during which the mild steel was held for 10 seconds without causing a shift was referred to as the tack development time.

(Tack range) The situation in which the tack generated above changes with the elapsed time was examined. The tack was measured as described above. Judgment, ○: No change in tack. X: Curing progressed and tack disappeared. Δ: Tack disappeared a little.

(Water resistance) (A) Boiling water immersion test: A test agent (thickness 1 mm, 10 mm square) cured for 7 days at room temperature was immersed in boiling water for 1 hour, taken out from the water, and the appearance was observed. Judgment: ○ No change in external shape. X Swells. Δ: Whitening is observed but there is no swelling. (B): The test agent of (A) was immersed in room temperature water for 15 days. The determination was based on the method (A).

(Adhesiveness) In order to evaluate the adhesiveness to various materials, using copper, polycarbonate, PET, bakelite, and wood (veneer), the two agents in Table 9 were mixed at room temperature, applied to each material, and thinly stretched at room temperature. Cured for 7 days to cure. (Various materials are used as standard materials. Surface treatment of materials is untreated). The cured product was subjected to a peeling test with a cutter knife. Judgment: ○ Don't peel off (bonded firmly). X Interface peeling. Δ Partially bonded.

(Deep part curability) In order to evaluate the curability of the cured product (surface curing, internal curing, uniform curing) using the two agents in Table 7 , the two agents were mixed at room temperature, and an aluminum bottle cap (diameter 30 mm, depth 25 mm), and the cured state was observed after 1 hour at room temperature, 1 day, and 7 days later. The numerical values in the table indicate the thickness of the cured layer cured from the surface.

Explanation of numerical values of the compounding tests in the table: The numerical values in Tables 1 to 3 indicate parts by weight. Numerical values in Tables 4 to 6 indicate parts by weight. However, the numerical values of the coverings 1 to 9 in Table 4 indicate the amounts of substances to be coated (the coverings 1 to 6 are the amount of cobalt naphthenate). The same applies to the amount of covering in Tables 5 to 6. The numerical values of the first agent (isocyanate) and the second agent (polyol) in Table 7 indicate milligram equivalents. The other components of the first agent and the second agent represent parts by weight per 100 parts by weight of each agent.

Hereinafter, the present invention will be described by way of examples.

(Example 1) . With respect to the reactive hot-melt curable composition, a blending test shown in Table 1 was conducted in order to evaluate the sticking property and (post-) curability of the thermoplastic polymer alone system. In the blending test, each component was collected so that the total amount thereof was about 2 grams at a ratio shown in the blending recipe, and mixed at a temperature of about 90 ° C. for about 15 seconds to prepare a test agent. The results of the evaluation test are also shown in the same table.

From the results in Table 1, the following can be said. Adhesiveness is good. The fixing time is determined by the cooling time of the melt, and both are fixed within 30 seconds, indicating that the initial fixing property is extremely excellent. (Post) It can be seen that curability proceeds even with the polymer alone. Further, it can be seen that a polymer having a high unsaturated group content is easily cured (crosslinked). It can also be seen that curing proceeds with the accelerator alone.

(Example 2) . With respect to the reactive hot-melt curable composition, a blending test shown in Table 2 was conducted in order to evaluate the sticking property and (post-) curability in the thermoplastic polymer / polymerizable material combination system. The blending test was performed according to the method of Example 1 . The polymerizable substances used in the experiment include the light ester TMP described above, light ester 3EG (chemical name: triethylene glycol dimethacrylate), light ester 14EG (polyethylene glycol dimethacrylate), and light ester HO (made by Kyoeisha Chemical). 2 hydroxyethyl methacrylate). The results of the evaluation test are also shown in the same table.

From the results in Table 2, the following can be said. Although the sticking property is good, the sticking property tends to decrease when the addition amount of the polymerizable substance increases, and it can be said that the sticking property can no longer be maintained when the addition amount exceeds about 50%. This is considered to be due to the plasticization (solubilization) effect by the polysynthetic substance. (Post) curability is greatly accelerated by the addition of a small amount of polymerizable material, indicating that cross-linking is effectively formed. Further, it is not recognized that the adhesiveness is lowered in this added region. It can be seen that the (post) cure rate can be controlled almost arbitrarily by adjusting the catalyst.

Table 3 shows a list of the coated bodies prepared for confirming the effects of the coated bodies with respect to the reactive hot melt curable composition. The coated body was prepared according to the method described above.

(Example 3) In order to see the effect of the coated body in the coated body addition system, room temperature storage stability, thermal stability,
The catalyst activity was evaluated. Table 4 shows a blending test for evaluating the storage stability. The results of the evaluation test are also shown in the table. Table 5 was subjected to a blending test for evaluating thermal stability. The results of the evaluation test are also shown in the table. Table 6 shows a blending test for evaluating the catalyst activity. The results of the evaluation test are also shown in the table.

From the results in Table 4, the following can be said. The room temperature storage stability can be kept extremely stable by using a covering. From the results of Table 5, it can be seen that the thermal stability is also significantly improved by using the covering. If it is a polymerization initiator and a polymerization accelerator that have been subjected to a coating treatment, they can coexist under heating (below the melting temperature of an easily heat-meltable substance). From the results of Table 6, it can be seen that, with respect to the catalytic activity, by heating to a temperature equal to or higher than the melting temperature of the easily meltable substance, no inhibition of curing is observed and stable curing (catalytic activity) is maintained. From this, it can be seen that the effect of the covering is remarkable.

(Reference Example 1) Regarding the two-component mixed fast fixing-post-curing composition, in order to evaluate a proper blended product in a synthetic polymer-crosslinking agent combined system, an expression of proper tack and tack range is shown. The compounding test of Table 7 was conducted. For those with tackiness and tack range, the test is performed by mixing the two agents at room temperature for about 10 seconds, and measuring tack development, tack range and (post-) curability, cured product internal curability, adhesion and water resistance. did. The results are also shown in the table.

From Table 7 , the proper blended product has good tack expression, tack range, curability inside the cured product, and water resistance. Further, the adhesiveness was relatively good except for the poor adhesion to aluminum. As a comparative example, a one-part moisture curing type of silicone was shown. This has good adhesion. However, the tack development is relatively long, and it can be said that control is difficult because the tack range is different from the inside of the cured product surface. Also, the internal curability is not sufficient.

Claims (3)

Reactive hot characterized in that it contains a urethane polymer having a molecular end at the hydroxyl group, a softening temperature of 30 to 200 ° C. and capable of forming a crosslink, and a crosslink catalyst coated with a heat-meltable substance. Melt curable composition. The reactive hot melt curable composition according to claim 1, further comprising an acrylate or methacrylate having a boiling point of 180 ° C. or higher as a crosslinking agent. A curing method comprising applying the reactive hot-melt curable composition according to claim 1 or 2 and promoting post-curing by heating after fixing.

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