TWI477524B - Polyurethane resin and application thereof - Google Patents

Description

Polyurethane resin and its utilization

The present invention relates to aluminum foil, adhesive film or rubber sheet (hereinafter collectively referred to as "film"), which has high adhesion and adhesion, and is quite suitable as a coating, a toner composition or an adhesive composition. A polyurethane resin having a resin component, an adhesive composition capable of performing film coating using the polyurethane resin, a film adhesive film layering method using the adhesive composition, and a film adhesive film laminate.

In a coating, an ink composition, and an adhesive composition having high adhesion and adhesion to a film, an aromatic polyester resin containing a terephthalic acid component or an isophthalic acid component is generally used. A polyurethane resin composed of an ester resin (hereinafter referred to as "polyester polyol resin") or a polyurethane-urea resin.

In the coating method of the above-described adhesive composition or the like, when the adhesive composition is a solventless type (a type containing no solvent), the adhesive composition is extruded in a molten state at a higher temperature exceeding 100 ° C. a film-like, linear or dot-like coating on a film; on the other hand, if the composition of the adhesive is a solvent-containing type, the adhesive is dissolved in an organic solvent or dispersed in water. The state is applied to the coating before the solvent component is volatilized.

However, if the resin used in the composition of the adhesive has a hydroxyl group having a molecular weight of about 0.4 to 4 mol/kg, the molecular weight of the polymer is low. It can be formed in a solvent-free state at a lower temperature of 100 ° C or lower, forming 10 Pa. s below the viscosity. At this time, the adhesive composition can be subjected to film-like melt coating on a large film area. Such a method using a solvent-free binder composition is evaluated as a method in which the environmental load is small because it is not necessary to use an energy source for drying the solvent and does not use an organic solvent.

For example, in the case where an adhesive composition is used to obtain a film laminate, the adhesive composition can be applied over a large area without using an organic solvent to form a film having a film thickness of 0.5 to 5 μm. The use of a squeeze roll coating method and an adhesive composition suitable for the coating method are disclosed in the specifications of Patent Documents 1 to 3 and Japanese Patent Application No. 2005-189329.

A polyurethane resin produced by using an aromatic polyester resin having a high adhesion to a film and having a low molecular weight as a polyol component, and a polyurethane obtained by denaturation of the above aromatic polyester resin with polyisocyanate - a urea resin or an aromatic polyester resin having a molecular weight of about 0.04 to 0.4 mol/kg at a molecular weight, and a film-like melting for a large area without using an organic solvent. When the coating composition of the coating is used, the above various resins are difficult to apply because the melt viscosity is too high.

In addition, the adhesive composition of the above-mentioned extrusion-type roll coating method is described in Patent Document 1 or Patent Document 3, and contains free inorganic in order to improve the adhesion and adhesion to the aluminum foil. Acid, organic acid or acid anhydride. on The acid or the like promotes hydrolysis of the polyester resin which is a main component of the adhesive composition by hydrolysis reaction with the ester, and has a side effect of deteriorating the quality of the resin. As described in Patent Document 2 or Patent Document 3, in order to reduce the melt viscosity of the resin, a substance obtained by mixing a large amount of a polyol component other than the aromatic polyester polyol does not contain a free inorganic acid, an organic acid or an acid. In the case of an anhydrate, the adhesive composition composed of the above aromatic polyester polyol has a problem that the adhesion to the film and the adhesion are insufficient.

As disclosed in Japanese Patent Application No. 2005-189329, in the above-mentioned circumstances, the acid component constituting the polyester resin, although containing a high concentration of phthalic acid, can form a low melt viscosity and can be used as a film in a large area. A solventless coating of a polyester resin having a specific composition. The polyester resin exhibits high adhesion to the film even if it does not contain a free inorganic acid, an organic acid or an acid anhydride.

However, when the polyester resin described in Japanese Patent Application Laid-Open No. 2005-189329 is used as a polyester polyol (main agent) as an adhesive composition, it is required in the same manner as other currently known adhesive compositions. The problem of hardening it for a long time. If a catalyst which promotes the hardening reaction of the polyester resin is used, the time required for the polyester resin to be hardened can be easily shortened. However, in this case, the life of the adhesive composition is shortened, which causes a problem in practical use.

Therefore, the method of using a solvent-free adhesive composition, the method of drying energy without a solvent, or the method of reducing the environmental load by using no organic solvent is used. The method obtains a high evaluation, but the method of coating a larger area after melting the solvent-free adhesive composition, especially in the field of a film requiring high adhesion, is always impossible. Get a breakthrough.

[Patent Document 1] Japanese Patent Publication No. 08-60131

[Patent Document 2] JP-A-2002-249745

[Patent Document 3] JP-A-2003-321664

The object of the present invention is to provide a polyurethane resin (Polyesterpolyol) which is effective as an adhesive composition, wherein the adhesive composition has high adhesion and adhesion to the film, and Low melt viscosity allows solventless coating at low temperatures. Further, another object of the present invention is to provide an adhesive composition comprising the urethane resin and having a reduced working life without shortening the curing time, and a film layering method using the adhesive composition, and The laminate of the film.

The above object is achieved by the following invention. That is, the present invention provides a polyurethane resin (c) characterized by a polyurethane resin obtained by reacting a polyhydric alcohol with a polyisocyanate, characterized in that the above polyol is 100 mol% of the total polyol. At least 80% by mole of the polyester polyol (a) (hereinafter referred to as "polyol (a)"), and when the total acid component of the polyol (a) is 100% by mole, at least There are 80 The molar % is a phthalic acid component and/or an isophthalic acid component; when the total alcohol component of the polyol (a) is 100% by mole, at least 50% by mole of the carbon number is 8 or less. The alkyl group is bonded to form 2 to 3 diol components by an ether bond; the above polyol (a) has an average of 0.55 to 5 mol/kg of hydroxyl groups at the molecular terminal; and the above polyisocyanate is 100% of polyisocyanate. In the case of % by mass, at least 70% by mass of the diisocyanate (b) having no ring structure and having a molecular weight of 250 or less in its own structure is contained.

In order to achieve the above-mentioned known technique, the inventors of the present invention found that the above-mentioned polyurethane resin (c) of the present invention has high adhesion to the film while having a low melt viscosity. That is, the polyurethane resin of the invention of the present invention has a melt viscosity of 10 Pa at 80 ° C. s below.

It is more worth mentioning that the polyurethane resin (c) of the present invention has the same melt viscosity at 80 ° C and the polyol (a) used to produce the polyurethane resin (c) (i.e., the acid component used). The polyol component is the same, and the melt viscosity is lower than that of the polyester polyol (a') having the same molecular weight as the urethane resin (c).

Comparing the polyurethane resin (c) of the present invention with the above polyol (a'), in the conventionally known common sense, the polyurethane resin (c) is considered to have a very high melt viscosity, but it can be found in the present invention. , polyurethane resin (c) is almost invisible The melt viscosity increases, and even more surprisingly, it is even lower than the melt viscosity of the above polyol (a').

Further, in the adhesive composition formed of the curing agent (II) having the main component (I) and polyisocyanate as a main component, the above-mentioned urethane resin (c) is used as a main component of the main component (I) (i.e., main When 50 to 100% by mass of the agent is used, the adhesive composition can shorten the time required for curing without using a curing catalyst.

Further, the above-mentioned adhesive composition is suitable for a film coating method in which a film thickness of about 0.5 to 5 μm is applied over a large area of a film to produce a film laminate.

Further, in the above-mentioned adhesive composition of the present invention, 50 to 100% by mass of the above-mentioned main component (I) is the above-mentioned melt viscosity at 80 ° C of 10 Pa. The urethane resin (c) below s is such that the isocyanate group content of the curing agent (II) is at least 10% by mass, and the stoichiometric ratio of the terminal group of the above main agent (I) to the above curing agent (II) (isocyanate group / When the hydroxyl group is 1.0 to 5.0 and the nonvolatile content is at least 98% by mass, and the composition is substantially free of an organic solvent, the film lamination processability of the adhesive composition and the adhesiveness of the laminate can be found. Very good.

According to the present invention, it is possible to provide a polyurethane resin which has high adhesion and adhesion to a film and which has a low melt viscosity and can be subjected to a solventless coating at a low temperature.

Further, since the urethane resin does not have a reduced life as the curing time is shortened, it can be effectively used as a main component of the adhesive composition, and by using the adhesive composition, a film having a low environmental load can be provided. Lamination method and film laminate.

The present invention will be described in more detail below with reference to the preferred embodiment.

The polyol (a) used in the production of the polyurethane resin (c) of the present invention, when the total amount of the acid component is 100 mol%, the acid component has at least 80 mol% of the phthalic acid component and/or The phthalic acid component; if the phthalic acid component and/or the isophthalic acid component are less than 80 mol% of the total acid component, the adhesion of the obtained urethane resin (c) to the film is lowered. Regarding the adhesion of the polyurethane resin (c) to the film, it is desirable to contain a higher proportion of phthalic acid in the total acid component, preferably the proportion of the above phthalic acid component accounts for at least 90% of the total acid component. Mole%, more preferably 100% by mole.

Further, in order to lower the melt viscosity of the obtained polyurethane resin (c) and to improve the solubility of the polyurethane resin (c) in an organic solvent, among the acid components constituting the polyol (a), the ratio of the phthalic acid component is It is preferable that the phthalic acid component is high, and it is most preferable that the phthalic acid component in the acid component is 100 mol%. Examples of the effective acid component of the phthalic acid component include phthalic acid, anhydrous phthalic acid, and/or an alkyl ester thereof. Further, examples of the effective acid component of the isophthalic acid component include isophthalic acid and/or an alkyl ester thereof. In addition to this, as a total As the acid component to be polymerized, a currently known acid can be used, and a dibasic acid is preferable.

The polyol (a) used in the production of the polyurethane resin (c) of the present invention is a polyester polyol formed from the acid component and the ethanol component, and when the total ethanol component is 100 mol%, at least 50 mol% must be a diol component formed by combining 2 to 3 alkyl groups having 8 or less carbon atoms by ether bonding. When the above-mentioned ethanol component is less than 50 mol% and does not pass through ether bonding to bond an alkyl group having 8 or less carbon atoms, the melt viscosity of the polyol (a) is improved. Therefore, it is preferable that the content of the diol component is at least 70 mol% of the total ethanol component, and more desirably 100 mol%.

Further, when the diol component is an ethanol component in which an alkyl group having more than 3 carbon atoms of 8 or less is bonded by ether bonding, the heat resistance of the polyurethane resin (c) obtained by the polyol (a) It will be lowered, and the deterioration of quality due to the heat of the urethane resin (c) at the time of melt coating will be more remarkable. Therefore, the polyol (a) constituting the urethane resin (c) of the present invention has a heat resistance of the obtained urethane resin (c) in consideration of the diol component, and the combination thereof constitutes the diol component and carbon. When the number is 8 or less, the number of ether bonds is preferably 1.

Further, when the diol component is formed of an alkyl group having a carbon number of more than 8 or more, the higher molecular weight lowers the content of the phthalic acid component as an acid component in the polyol (a). The adhesion of the polyurethane resin (c) obtained from the alcohol (a) to the film is lowered. Therefore, if the adhesion to the film is taken into consideration, The number of carbon atoms of the alkyl group constituting the above ethanol component is preferably 8 or less.

When the total component of the above ethanol component is 100 mol%, as a diol component which constitutes at least 50 mol% of an alkyl group bonded by 2 to 3 carbon atoms or less by ether bonding, it is possible to use, for example, digan. The alcohol, triethylene glycol, dipropylene glycol, and other triethylene glycol are added to the alkylene glycol having a carbon number of 8 or less, and one or two ethylene oxide, ethylene oxide, tetrahydrofuran, and the like are additionally opened. Other ethanol components which can generate copolymerization are preferably ethylene glycol having two hydroxyl groups, although the currently known ethanol component can be used.

Further, the polyol (a) used in the production of the urethane resin (c) of the present invention is preferably a polyester polyol having a hydroxyl group having an average of 0.55 to 5 mol/kg at the molecular terminal. When the content of the hydroxyl group exceeds 5 mol/kg, the adhesion of the obtained polyurethane resin (c) to the film is lowered. On the other hand, if the hydroxyl group content of the polyol (a) is less than 0.55 mol/kg, the melt viscosity of the obtained polyurethane resin (c) is increased, and when it is used as an adhesive composition, it is difficult to Film coating is carried out on a large area in the case of a solvent.

The method for producing the polyol (a) used in the production of the polyurethane resin (c) of the present invention can be carried out by a method for producing a polyester resin known in the prior art, that is, by using the above polybasic acid and/or its alkane. The ester is obtained by coexisting with the above-mentioned polyvalent ethanol as needed and the esterification catalyst, and optionally, in the presence of an oxidation inhibitor, by a polycondensation reaction at a temperature of from 140 to 250 °C. The esterification catalyst can be used as currently known, but it is preferably a titanium alkoxide. As the oxidation preventive agent, those known to date can be used, but a phosphite system is preferred.

The polyisocyanate (b) used in the production of the polyurethane resin (c) of the present invention is a diisocyanate having no ring structure and a molecular weight of 250 or less on the carbon skeleton. The desirable diisocyanate may, for example, be cyclobutane diisocyanate, hexamethylene diisocyanate, 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate or the like.

In the production of the polyurethane resin (c) of the present invention, a compound containing active hydrogen such as a polyhydric alcohol other than the above may be used, but the amount thereof is less than 20 mol% in the total polyol. When the ratio of the other active hydrogen-containing compound is increased, the adhesion and adhesion of the obtained polyurethane resin (c) to the film are lowered, and the melt viscosity is also improved. Therefore, it is preferable that the ratio of the other active hydrogen-containing compound is 10 mol% or less of the total polyol component, and more desirably 0 mol%. As the other active hydrogen-containing compound, a polyurethane resin raw material such as a currently known polyol or polyamine can be used.

In the production of the urethane resin (c) of the present invention, although polyisocyanate other than the above may be used, the other polyisocyanate should not constitute 30% by mass of the entire polyisocyanate. When the ratio of the other polyisocyanate is increased, the melt viscosity of the obtained polyurethane resin (c) is increased. Therefore, the amount of other polyisocyanate used is preferably 15% by mass or less, and more preferably 0% by mass. As the other polyisocyanate, polyisocyanate, polyisocyanate polymer, polyisocyanate adduct, terminal isocyanate type prepolymer, and the like which are currently known in the polyurethane resin raw material can be used.

In the method for producing the polyurethane resin (c) of the present invention, a method for producing a polyurethane resin which is currently known can be applied. That is, the above-mentioned polyol (a), a known other polyhydric alcohols compound or a polyamine compound, and the like, an active hydrogen-containing compound, and the above-mentioned polyisohydrogenate (b) and The currently known polyisocyanate compound to be added is obtained by a polyaddition reaction at a normal temperature of -250 ° C, if necessary, in the presence of a urethane catalyst, and optionally in the presence of an organic solvent. A urethane catalyst can be used as currently known, but a stannous salt system is preferred.

In the production of the above urethane resin (c), if a solvent-free adhesive composition is actually obtained, it is preferable not to use an organic solvent, but an organic solvent may be used as needed, and then a method known in the art is used. Remove organic solvents. The organic solvent can be used as known, but it is preferably a ketone system and/or an ester group.

The main component (polyol) (I) used in the adhesive composition of the present invention, when the total polyol is 100% by mass, 50 to 100% by mass of the above is the polyurethane resin (c) of the present invention. The main component (I) used in the adhesive composition of the present invention, when the total polyol is 100% by mass, wherein other polyol components may be used in an amount of from 0 to 50% by mass, but the proportion of the above other components is increased. The adhesion and adhesion of the adhesive composition to the film are reduced. Therefore, the ratio of the above other components is preferably 20% by mass or less, and more preferably 0% by mass.

The hardener (polyisocyanate) (II) used in the adhesive composition of the present invention is a polyisocyanate having an isocyanate group content of at least 10% by mass. Isocyanate When the content of the base is less than 10% by mass, the amount of the curing agent required for curing is increased, and as a result, the content of the urethane resin (c) is lowered, and the adhesion and adhesion of the adhesive composition to the film are improved. reduce. As the polyisocyanate of the hardener (II), a currently known polyisocyanate compound having an isocyanate group content of at least 10% by mass can be used.

The main component (I) and the hardener (II) used in the adhesive composition of the present invention have a stoichiometric ratio (hydroxyl group, hydroxyl group) of a terminal group (hydroxyl group, isocyanate group) of 1.0 to 5.0. The ideal is 1.5~3.0. If the stoichiometric ratio of the terminal group is less than 1.0, the hardening of the adhesive composition cannot be completed. On the other hand, if the stoichiometric ratio of the terminal group exceeds 5.0, a large amount of water must be supplied in order to achieve hardening, resulting in hardening. It takes a long time. Further, since the content of the urethane resin (c) is lowered, the adhesion and adhesion of the adhesive composition are lowered for the film.

The adhesive composition of the present invention may be blended with a coloring agent, a dispersing agent, a surfactant, a foaming agent, an antifoaming agent, a viscosity adjusting agent, and a levelling agent, which are currently known pigments or dyes, as needed. , stabilizers, UV absorbers, coupling agents, adhesion inhibitors, catalysts, service life extenders, plasticizers, fillers, etc. are obtained. In particular, the catalyst has been used in the past in order to shorten the curing time, but it is disadvantageous in that the life is shortened. The adhesive composition of the present invention is used in a smaller amount than in the conventional method even when a catalyst is used, and is effective for extending the service life.

The adhesive composition of the present invention, wherein the nonvolatile matter accounts for at least 98% by mass, is preferably one which does not substantially contain an organic solvent. Here, the reason why the "actual" non-volatile content is less than 100% by mass is considered to be the addition of a small amount of water to be mixed, or the carbonic acid gas generated by the reaction between the polyisocyanate and the water, and the ethanol component which is decomposed by the coupling agent. Will form a volatile component.

A method of laminating a film using the adhesive composition of the present invention can be applied to a conventionally known lamination method. Basically, the main agent (I) and the hardener (II) are heated and melt-mixed to prepare an adhesive composition, and then the adhesive film is coated with an adhesive composition, and then with other adhesive films, or sheets, or plates. Cooperating with other types of substrates, followed by hardening and aging at room temperature or under heating conditions, but the adhesive composition can be applied to both sides of the film as needed, and in order to promote post-coating Following the flat dispersion of the composition of the agent, a heating step or a placing step can also be added.

The preparation method of the adhesive composition of the present invention can be carried out by using the main agent (I) and the hardener (II), respectively, using different pumps, using a mixer to automatically calculate the supply and mixing and pouring the device. It is desirable that the parts to be used are appropriately mixed and prepared into an adhesive composition. Since the adhesive composition prepared by mixing the main component (I) and the curing agent (II) starts to undergo a hardening reaction immediately after the mixing and preparation, and the viscosity is gradually increased, it is not preferable to prepare a large amount of the preparation.

The coating method of the adhesive composition of the present invention can be applied to a conventionally known coating method. Specific examples thereof include a squeeze roll coating method, a reverse roll coating method, a curtain coating method, and a knife coating method. Film thickness and coating method of the composition of the subsequent agent The method varies depending on the characteristics of the film substrate (coated film) or the necessary subsequent functions. For example, when the film substrate is thin and the surface smoothness is high and the use of a high bonding strength is not required, the coating film thickness of the adhesive composition is preferably about 1 to 5 μm, and the coating method in this case is preferable. The squeeze roll coating method is ideal. Further, when the film base material is thick and the smoothness of the adhesive surface is poor, and the use of a high adhesive strength is required, the coating film thickness of the adhesive composition is preferably about 5 to 100 μm, and in addition to the squeeze roll coating method. The method is ideal.

The adhesive film substrate of the present invention is laminated to a film substrate, which is currently known for surface treatment, and is represented by polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinyl alcohol. And various ethylene plastic copolymers, polyamines represented by 6 nylon, polyesters represented by polyethylene terephthalate (PET), and the like, and foams thereof, and coated on the above surface There are various known polymer coating agents represented by polyvinylidene chloride, and a film substrate formed by metal evaporation, oxidized cerium evaporation, and inorganic layer represented by alumina evaporation, and the like. A metal material typified by aluminum foil, copper foil, or the like, a woven fabric, a non-woven fabric, paper, or the like, a monomer or a substrate which has been laminated in advance.

Among them, aluminum foil and PET are the most suitable adhesive film substrates which exhibit excellent adhesion of the adhesive composition of the present invention, and a laminate having the characteristics of the present invention can be formed by using the laminate of these adhesive film substrates.

(Example)

The synthesis examples, examples, comparative examples and reference examples are listed below, and the invention is made A specific description.

[Synthesis Example a-1~a-10] <Method for Producing Polyol (a1: Synthesis Example a-1)>

538 g of anhydrous phthalic acid, 462 g of diethylene glycol, and 1 g of triphenyl phosphate were placed in a flask, and the mixture was heated for 5 hours to 230 ° C while stirring under a nitrogen stream, and then esterified by distilling off water. . When the water distillation was just stopped, 0.1 g of tetra-n-butoxytitanium polymer was added, the temperature was raised to 250 ° C, and polymerization was carried out under a reduced pressure of 10 torr to obtain a polyhydric hydroxyl group having a concentration of 1.9 m/kg. Alcohol (a1). The polyol (a1) has a melt viscosity of 0.9 Pa at 80 ° C. s.

<Method for Producing Polyol (a2: Synthesis Example a-2)>

In the same manner as the polyol (a1), a polyol (a2) having a hydroxyl group concentration of 1 mol/kg was obtained from 554 g of anhydrous phthalic acid and 462 g of diethylene glycol. The polyol (a2) has a melt viscosity of 0.5 Pa at 80 ° C. s.

<Method for Producing Polyol (a3: Synthesis Example a-3)>

In the same manner as the polyol (a1), a polyol (a3) having a hydroxyl group concentration of 1.8 mol/kg was obtained from 603 g of isophthalic acid and 462 g of diethylene glycol. The polyol (a3) has a melt viscosity of 12 Pa at 80 ° C. s.

<Method for Producing Polyol (a4: Synthesis Example a-4)>

In the same manner as the polyol (a1), a polyol (a4) having a hydroxyl group concentration of 5.3 mol/kg was obtained from 429 g of anhydrous phthalic acid and 571 g of diethylene glycol. The polyol (a4) has a melt viscosity of 0.2 Pa at 80 ° C. s.

<Method for Producing Polyol (a5: Synthesis Example a-5)>

In the same manner as the polyol (a1), a polyol (a5) having a hydroxyl group concentration of 0.50 mol/kg was obtained from 568 g of anhydrous phthalic acid and 432 g of diethylene glycol. The polyol (a5) has a melt viscosity of 12 Pa at 80 ° C. s.

<Method for Producing Polyol (a6: Synthesis Example a-6)>

In the same manner as the polyol (a1), a polyol (a6) having a hydroxyl group concentration of 2.1 mol/kg was obtained from 603 g of terephthalic acid and 462 g of diethylene glycol. The polyol (a6) has a melt viscosity of 60 Pa at 80 ° C. s. Further, the molten state of the resin at 80 ° C is a heterogeneous state in which a part of the crystal component is dispersed.

<Method for Producing Polyol (a7: Synthesis Example a-7)>

The same as the polyol (a1), a polyhydric alcohol having a hydroxyl group concentration of 2.1 mol/kg was obtained from 538 g of anhydrous phthalic acid and 463 g of neopentyl glycol. 7). The polyol (a7) has a melt viscosity of 430 Pa at 80 ° C. s.

<Method for Producing Polyol (a8: Synthesis Example a-8)>

In the same manner as the polyol (a1), a polyol (a8) having a hydroxyl group concentration of 2 mol/kg was obtained from 539 g of adipic acid and 441 g of 1,4-butanediol. The polyol (a8) has a melt viscosity of 0.2 Pa at 80 ° C. s.

<Method for Producing Polyol (a9: Synthesis Example a-9)>

In the same manner as the polyol (a1), a polyol (a9) having a hydroxyl group concentration of 1 mol/kg was obtained from 583 g of adipic acid and 417 g of 1,4-butanediol. The polyol (a9) has a melt viscosity of 0.5 Pa at 80 ° C. s.

The above polyols a1 to a9 are shown in Table 1.

(abbreviation)

APA: anhydrous phthalic acid

IPA: isophthalic acid

TPA: terephthalic acid

AA: adipic acid

DEG: diethylene glycol

NPG: neopentyl glycol

BD: 1,4-butanediol

Examples c1 to c4, Comparative Examples c1 to c6 <Polyurethane Resin (c)> Example c1 (polyurethane resin c1)

The flask was charged with 1053 g of a polyol (a1) and 73.4 g of hexamethylene diisocyanate, and a polyaddition reaction was carried out at 75 ° C for 8 hours while stirring under a nitrogen stream to obtain a hydroxyl group concentration of 1 mol. /kg of polyurethane resin (c1). The resin has a melt viscosity of 4 Pa at 80 ° C. s.

Example c2 (polyurethane resin c2)

In the same manner as the urethane resin (c1), a polyurethane resin (c2) having a hydroxyl group concentration of 1 mol/kg was obtained from 1053 g of the polyol (a1) and 90.8 g of the lysine diisocyanate. The resin has a melt viscosity of 5.7 Pa at 80 ° C. s.

Comparative Example c1 (Polyurethane Resin c3)

In the same manner as the urethane resin (c1), a polyurethane resin (c3) having a hydroxyl group concentration of 1 mol/kg was obtained from 1053 g of the polyol (a1) and 94.6 g of isophorone diisocyanate. The resin has a melt viscosity of 15 Pa at 80 ° C. s.

Comparative Example c2 (Polyurethane Resin c4)

In the same manner as the urethane resin (c1), a polyurethane resin having a hydroxyl group concentration of 1 mol/kg was obtained from 1053 g of the polyol (a1) and 105.2 g of 4,4'-diphenylmethane diisocyanate (c4). . The resin has a melt viscosity of 18 Pa at 80 ° C. s.

Example c3 (polyurethane resin c5)

In the same manner as the urethane resin (c1), a urethane resin (c5) having a hydroxyl group concentration of 0.50 mol/kg was obtained from 1053 g of the polyol (a2) and 42.4 g of hexamethylene diisocyanate. The resin has a melt viscosity of 9 Pa at 80 ° C. s.

Example c4 (polyurethane resin c6)

Same as polyurethane resin (c1), from polyol (a3) 1053g In 65.3 g of hexamethylene diisocyanate, a polyurethane resin (c6) having a hydroxyl group concentration of 1 mol/kg was obtained. The resin has a melt viscosity of 9.5 Pa at 80 ° C. s.

Comparative Example c3 (Polyurethane Resin c7)

In the same manner as the urethane resin (c1), a urethane resin (c7) having a hydroxyl group concentration of 1 mol/kg was obtained from 1053 g of the polyol (a4) and 347.8 g of hexamethylene diisocyanate. The resin has a melt viscosity of 6.5 Pa at 80 ° C. s.

Comparative Example c4 (Polyurethane Resin c8)

In the same manner as the urethane resin (c1), a polyurethane resin (c8) having a hydroxyl group concentration of 1 mol/kg was obtained from 1053 g of the polyol (a6) and 89.2 g of hexamethylene diisocyanate. The resin has a melt viscosity of 51 Pa at 80 ° C. s. Further, the molten state of the resin at 80 ° C is a heterogeneous state in which a part of the crystal component is dispersed.

Comparative Example c5 (Polyurethane Resin c9)

The same as the urethane resin (c1), since the stirring could not be performed at 75 ° C, the temperature was changed to 120 ° C, and the hydroxyl group concentration of 1 mol was obtained from 1053 g of the polyol (a7) and 89.2 g of the hexamethylene diisocyanate. Kg of polyurethane Ester resin (c9). The melt viscosity of the resin at 80 ° C could not be measured (over 500 Pa.s).

Comparative Example c6 (Polyurethane Resin c10)

In the same manner as the urethane resin (c1), a urethane resin (c10) having a hydroxyl group concentration of 1 mol/kg was obtained from 1053 g of the polyol (a8) and 81.6 g of hexamethylene diisocyanate. The resin has a melt viscosity of 1 Pa at 80 ° C. s.

The melt viscosity of the polyester polyol (a2, a5, a9) having a similar concentration of the urethane resin and the hydroxyl group at 80 ° C is described in Table 2-2 for reference.

(abbreviation)

HDI: hexamethylene diisocyanate

LDI: lysine diisocyanate

IPDI; isophorone diisocyanate

MDI: 4,4'-diphenylmethane diisocyanate

(abbreviation)

HDI: hexamethylene diisocyanate

<Manufacturing method of compounding agent (a2-9)>

750 g of the polyol (a2) and 250 g of the polyol (a9) were mixed to obtain a compounding agent (a2-9). The concentration of the hydroxyl group of the main agent is 1 mol / Kg.

<Method for Producing Hardener (IIa)>

The TAKENATE D-165N500g of Takeda Pharmaceutical Industry was mixed with CORONATE HX500g of Japanese Polyurethane to obtain a hardener (IIa). The hardener had an isocyanate group concentration of 5.3 mol/kg (the isocyanate group content was 22% by mass).

<Method for Producing Hardener (IIb)>

Into the flask, DURANATE TPA-100865 g of Asahi Kasei and 135 g of a polyhydric alcohol (a1) were placed, and a polyaddition reaction was carried out at 75 ° C for 8 hours while stirring under a nitrogen stream to obtain a curing agent (IIb). The hardener had an isocyanate group concentration of 4.5 mol/kg (isocyanate group content of 19% by mass).

Examples 1 to 5 and Comparative Examples 1 to 12 <Adhesive Composition>

As the main component, the polyol (a2, a5, a9) obtained in the above synthesis example may be blended with a polyol (a2-9), a urethane resin (c1 to c10), and a hardener (IIa, IIb), according to Table 3. The ratios shown are mixed to obtain the adhesive compositions of the present invention and comparative examples.

〔Evaluation results〕

Table 3-2

Table 3-3

Regarding the evaluation described in the table, the method was carried out as follows.

(hydroxyl concentration)

The evaluation object was measured based on JIS K 0070.

(isocyanate group concentration)

The evaluation object was measured based on JIS K 1603.

(melt viscosity)

The evaluation object uses a BM type rotary viscometer (rotational Viscometer) measures the melt viscosity at 80 °C.

(painting property)

When the film coating was performed at a thickness of 2 μm by a squeeze roll coater, the coating suitability was evaluated.

○: Good appearance, △: abnormal appearance (poor smoothness of coating), X: no coating was possible

(aluminum foil adhesion)

For a 25 μm thick aluminum foil, the adhesive composition was subjected to a film coating at a thickness of 2 μm, and then bonded to a 60 μm thick corona surface treated linear low-density polyethylene resin, and after 7 days at 40 ° C When the coating film was directly peeled off from the aluminum foil at 25 ° C, the peeling state was evaluated.

○: The substrate is broken, X: It is easy to peel off, ND: It is impossible to apply and there is no data.

(PET adhesion)

The film composition was applied to a film having a thickness of 25 μm with a thickness of 2 μm, and then bonded to a linear low-density polyethylene resin having a thickness of 60 μm and a corona surface treatment for reinforcing the coating film at 40 ° C. After 7 days, when the film was peeled off from the PET with a direct-locking low-density polyethylene resin at 25 ° C, The peeling state was evaluated.

○: The substrate is broken, X: It is easy to peel off, ND: It is impossible to carry out the coating and there is no data to follow.

(hardenability)

When the PET adhesiveness was evaluated, the film was peeled off immediately after 3 days at 40 ° C, and the cured state of the adhesive composition was evaluated.

○: good hardening (no adhesion), X: no hardening (adhesive), ND: no coating, no data

As described above, according to the present invention, it is possible to provide a polyurethane resin which has high adhesion to a film, low melt viscosity, excellent film coating suitability, and a hardening time as a composition with a polyisocyanate. These resins are particularly suitable as a resin for an adhesive which can impart high adhesion to a film, in addition to being applicable to various applications.

Claims (3)

An adhesive composition characterized by comprising a main component (I) containing a polyol as a main component and a curing agent (II) having a polyisocyanate as a main component, if the above-mentioned main component When the total amount of the agent (I) is 100% by mass, 50 to 100% by mass thereof is obtained by a polyaddition reaction of the following polyol (1) with the following polyisocyanate (2) and its melt viscosity at 80 ° C For 10Pa. s below the urethane resin (c), and the hardener (II) has an isocyanate group content of at least 10% by mass, and the stoichiometric ratio of the terminal group of the above main agent (I) and the above hardener (II) (isocyanate) The base/hydrogen group is 1.0 to 5.0, the nonvolatile content is at least 98% by mass, and is substantially an organic solvent-free composition, and (1) the above polyol is 100 mol% of the total polyol, wherein At least 80% by mole of the polyester polyol (a), and when the total acid component of the polyester polyol (a) is 100% by mole, at least 80% by mole of the phthalic acid component and/or Or an isophthalic acid component, if the total ethanol component of the polyester polyol (a) is 100 mol%, at least 50 mol% thereof is an alkyl group bonded by an ether to 2 to 3 carbon atoms or less The diol component, the above polyester polyol (a), has an average hydroxyl group at the molecular end of 0.55 to 5 Mohr/kg; (2) The above polyisocyanate (when the total polyisocyanate is 100% by mass), at least 70% by mass of the diisocyanate (b) having a ring structure and a molecular weight of 250 or less in its structure. A method of laminating a method of laminating a plurality of sheets of a film or a sheet by using an adhesive composition as recited in claim 1 of the patent application. A laminate comprising the use of an adhesive composition in the first item of the patent application, wherein a plurality of sheets of film or paper are laminated.