KR20120078007A - Laminated adhesive composition for steel - Google Patents

Abstract

PURPOSE: An adhesive composition for laminate steel sheets comprises excellent adhesion, durability, water resistance, and storage stability even in low temperature, and to effectively prevent the change of adhesion and durability even in long-term exposure. CONSTITUTION: An adhesive composition for laminate steel sheets comprises a polyester-polyurethane resin having crystallinity, silane-modified epoxy resin, epoxy silane, phosphoric acid-modified ester resin, a crosslinking agent, a latent epoxy hardener, an epoxy curing accelerator, and block isocyanate. The polyester-polyurethane resin consists of 100.0 parts by weight of polyester polyol with molecular weight of 800-2500, and 5-15 parts by weight of isocyanate. The silane modified epoxy resin is formed by addition reaction of silane coupling agent to an epoxy resin with the epoxy equivalent of 400-6000 g/eq.

Description

Laminated adhesive composition for steel sheet

It relates to an adhesive composition for laminated steel sheet. More specifically, the present invention relates to an adhesive for laminating soft and hard polyvinyl chloride (PVC) film, PET, fluorine film, and the like by applying an adhesive on a cold rolled steel plate or a plated steel sheet, and particularly, at a low temperature, excellent adhesion, heat resistance, water resistance, and The present invention relates to an adhesive composition for laminated steel sheets having storage stability.

Laminated steel sheets in which plastic films subjected to printing or embossing are bonded to steel sheets are used for home appliances, interior and exterior building materials of homes, etc., and are used as materials with enhanced aesthetics and luxury compared to conventional metal coatings. These laminated steel sheets are generally manufactured by coating an adhesive on a steel sheet and bonding a plastic film together.

In particular, the laminated steel sheet is coated with an adhesive on a cold rolled steel sheet or a plated steel sheet to pass a drying furnace at a predetermined temperature for a predetermined time to apply a soft and hard polyvinyl chloride (PVC) film to the upper surface of the sheet while the applied adhesive is activated by heat. It is produced by adhering while pressing by the pressure of the roll. Such a lamination method is used as a material with high designability or high quality compared to conventional metal coating, and has the advantage of making a large amount of products in less time than metal coating.

On the other hand, as a material for plastic films adhered to a steel sheet, for example, polyvinyl chloride has been widely used and used conventionally, and a laminated steel sheet using a polyolefin film as an alternative material having a performance equivalent to that of the polyvinyl chloride laminate steel sheet. Also known.

As a conventional adhesive agent used when laminating a polyvinyl chloride film on a steel sheet, for example, an epoxy resin, an amino resin adhesive, a polyester polyol, and a polyisocyanate resin adhesive are known. There is a liquid type. When laminating a polyvinyl chloride film on a steel plate using these, the required physical properties are generally achieved. However, since a polyolefin film is a hard-adhesive material, when the adhesive agent for polyvinyl chloride film laminates is used as it is, there exists a problem that a bad adhesion will arise.

On the other hand, the adhesive composition useful for bonding a flexible polyvinyl chloride film or the like on a plated steel sheet such as zinc or chromium has been disclosed in Korean Patent Publication No. 2008-0027549, but the adhesive composition is used to bond the film and the plated steel sheet. In order to achieve the high temperature of the surface temperature of the steel sheet at least 200 to 250 ℃, for this purpose the temperature of the drying furnace should be at least 250 to 350 ℃. In other words, in order to bond polyvinyl chloride or the like onto a plated steel sheet such as zinc or chromium according to a conventional method, the temperature of a drying furnace which should be used for solvent lubrication and adhesive activity should be high, and as the temperature of the drying furnace increases, manufacturing cost increases. And there was a disadvantage that the instability of the temperature increases.

Therefore, there is a need for an adhesive composition for laminated steel sheets having excellent adhesion, heat resistance, water resistance and storage stability even at low temperatures.

In addition, there is a need for an adhesive composition for a steel sheet for laminates, which does not change in adhesive strength and durability even after prolonged exposure.

In addition, by having an excellent adhesion even at low temperatures, there is a need for an adhesive composition for laminated steel sheets that can reduce manufacturing costs and reduce temperature instability.

The present invention has been made by the above-described needs, and a first object of the present invention is to provide an adhesive composition for laminated steel sheets having excellent adhesion, heat resistance, water resistance and storage stability even at low temperatures.

In addition, a second object is to provide an adhesive composition for a steel sheet for laminate, which does not change in adhesive strength and durability even after long exposure.

In addition, a third object is to provide an adhesive composition for laminated steel sheets that can have excellent adhesion even at low temperatures, thereby reducing manufacturing costs and reducing temperature instability.

The object of the present invention as described above is a polyester-polyurethane resin having crystallinity; Silane-modified epoxy resins; Epoxy silanes; Phosphoric acid modified ester resins; A crosslinking agent; Latent epoxy curing agents; Epoxy curing accelerators; It can be achieved by providing an adhesive composition for a laminated steel sheet comprising a block isocyanate and a mixed solvent.

Moreover, polyester- polyurethane resin is 100 weight part of polyester polyols whose molecular weight is 800-2500; And 5 to 15 parts by weight of isocyanate.

The polyester polyol may be formed by synthesizing terephthalic acid and glycols in order to have crystallinity, and having an acid value of 1 to 10 KOHmg / g.

The polyester-polyurethane resin may have a number average molecular weight of 20000 to 80000.

In addition, the silane-modified epoxy resin may be formed by addition reaction of a silane coupling agent to an epoxy resin having an epoxy equivalent of 400 to 6000 g / eq.

In addition, the phosphoric acid-modified polyester resin may be characterized in that the phosphite system.

The crosslinking agent may be a single molecule such as glycols or an oligomer obtained by polyesterification.

In addition, the latent epoxy curing agent may be at least one of an amine adduct, dihydrazide, and dicyandiamine.

In addition, epoxy curing accelerators include 2-methyl imidazole, 2-phenyl imidazole, 2-ethyl-4-methyl imidazole, 1- Benzyl-2-methyl imidazole, 1-cyanoethyl-2-ethyl-4-methyl imidazole, 1- 1-cyanoethyl-2-methyl imidazole-trimellitate and 2-phenyl-4-methyl-5-hydroxymethyl imidazole (2-phenyl-4-methyl- 5-hydroxymethyl imidazole) can be characterized in that at least one.

In addition, the block isocyanate may be blocked by any one of 3,5-dimethylpyrazole, diethyl malonate, and methyl ethyl ketoxime.

Furthermore, with respect to the total weight of the whole composition, 50-80 weight part of polyester-polyurethane resins; 1 to 10 parts by weight of the silane-modified epoxy resin; 0.1 to 2 parts by weight of epoxy silane; 0.1 to 5 parts by weight of phosphoric acid modified ester resin; 0.1 to 0.2 parts by weight of a crosslinking agent; 0.01 to 1 part by weight of latent epoxy curing agent; 0.01 to 1 part by weight of an epoxy curing accelerator; 3 to 15 parts by weight of block isocyanate; And 20 to 40 parts by weight of a mixed solvent.

In addition, the adhesive composition for a laminated steel sheet may be characterized by having a nonvolitile of 35%.

According to one embodiment of the present invention, the present invention is used by adding a silane-modified epoxy resin, epoxy silane, phosphate-modified ester resin, crosslinking agent, latent epoxy curing agent, epoxy curing accelerator, block isocyanate together with polyester-polyurethane As the adhesive, it is possible to ensure excellent adhesion, especially to soft and hard polyvinyl chloride film films.

In addition, low-molecular-weight silane used as an adhesion promoter together with polyester-polyurethane is added and reacted with epoxy, so that even when the composite film is used for a long time, it has an excellent effect of having excellent durability even in environments such as adhesion and hot water resistance.

On the other hand, when laminating a film on a steel sheet, it contains polyester polyurethane with strong adhesive strength as a main component, and it has excellent adhesion, heat resistance, water resistance, chemical resistance, etc. It can ensure and effectively prevent the change in adhesive strength and durability even in long time exposure.

Hereinafter, preferred embodiments of the present invention will be described in detail. In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

<Configuration of Adhesive Composition>

The present invention relates to a low-temperature type polyurethane adhesive composition for film laminate steel sheet, in particular polyester-polyurethane resin, silane-modified epoxy resin, epoxy silane, phosphoric acid-modified with crystallinity obtained by reacting with isocyanate using polyester polyol Ester resins, crosslinking agents, latent epoxy curing agents, epoxy curing accelerators, block isocyanates and mixed solvents.

The polyester-polyurethane resin may be obtained by polymerizing an isocyanate with a polyester polyol obtained by polymerizing an aromatic dibasic acid compound, an aliphatic dibasic acid compound and a glycol. The polyester polyol used in the present invention is a polyester polyol having an -OH group at the sock end, and has a number average molecular weight of 500 to 3,000, preferably 800 to 2500, and may be used for viscosity and ease of manufacture. The average molecular weight can be less than 2,000.

The aromatic dibasic acid compound may include at least one selected from the group consisting of isophthalic acid, terephthalic acid, phthalic anhydride, trimellitic acid, dimethyl terephthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, naphthalic acid, and the like. The base acid compound may include at least one selected from the group consisting of adipic acid, sebacic acid, azeraic acid, fumaric acid, succinylic acid, glutonic acid, trimetic acid, hemimelic acid, and the like.

Glycols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, dipropylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, trimethylene glycol, methyl Propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5 pentanediol, 2-methyl-1,8 octanediol, 1 Glycols, such as 9, nonanediol, hexylene glycol, trimethylpentanediol, and hydrogenated bisphenol A, can be used alone or a mixture thereof can be used.

On the other hand, the production method of the polyester polyol is polycondensation by heating the glycol and aromatic and aliphatic dibasic acid to 200 to 260 ℃ in the presence of an esterification catalyst to produce a crystalline polyester polyol, and to the crystalline polyester polyol Other glycols, aromatic dibasic acids and aliphatic dibasic acids are polycondensed by heating to 200 to 280 ° C. in the presence of an esterification catalyst, and vacuum at 700 mmHg at a temperature of 200 to 280 ° C. when the acid value of the reaction mixture reaches around 15 KOHmg / g. The esterification reaction is continued under reduced pressure. When the acid value of the reaction mixture reaches around 5 KOHmg / g, the desired polyester polyol can be obtained by stopping the reaction and cooling.

The polyester polyol usable in the present invention may have an acid value of 1 to 10 KOHmg / g, preferably 1 to 5 KOHmg / g. When the acid value is less than 1 KOHmg / g, the reaction time is long, the molecular weight is large, and the pot life is shortened during the adhesive reaction is not preferable, when the excess of 10 KOHmg / g is not preferable because the large pot life is long.

The polyester-polyurethane of the present invention is prepared by using the polyester polyol as described above, wherein the polyester-polyurethane may be prepared by further adding an organic isocyanate to the polyester polyol.

Here, as organic diisocyanate, Preferably xylene diisocyanate, 4.4- diphenylmethane diisocyanate, 2.6- dilene diisocyanate, 1.6-hexamethylene diisocyanate, isophorone diisocyanate, 4.4'-methylene bis cycloisocyanate, 1.4 -Tetramethylene diisocyanate, 1.4-cyclohexanediisocyanate, toluene-2.6-diisocyanate, naphthalin 1.5-diisocyanate, 4-methoxy-1.3-phenylene diisocyanate, 4-chloro-1.3phenylenedi isocyanate, 2.4-dimethyl -1.3-phenylene diisocyanate, etc. can be used, and can be used individually or in mixture of 2 or more types. In addition, a polyfunctional polyisocyanate such as a compound in which 3 mol of 2.6-trilene diisocyanate is added to 1 mol of trimethylolpropane may be used in combination.

In addition, the organic diisocyanate may be included in an amount of 1 to 20 parts by weight, preferably 5 to 15 parts by weight, based on the total weight of the polyurethane polyol, and it is preferable to maintain such a content range in terms of adhesion, water resistance and flexibility.

The organic diisocyanate may also be used such that the isocyanate groups are equivalent ratios of 0.2 to 1, preferably 0.5 to 0.8, relative to the hydroxyl groups of the polyol. In this case, when the equivalent ratio is less than 0.2, there may be a problem that the adhesion strength is lowered due to less urethane bonds, and when it exceeds 1, there is no residual hydroxyl group, which is difficult to manufacture and is not suitable for use.

Isocyanate is preferably used having a high reactivity and the reaction temperature may be 70 to 140 ℃, preferably 80 to 120 ℃. The reaction temperature is preferably polymerized at a low temperature in the early stage, and the polymerization is carried out by raising the temperature as the polymerization proceeds. In terms of reaction rate, an ideal polymer product can be obtained. If the high temperature reaction from the beginning, the non-ideal bonds may increase, resulting in poor physical properties.

The number average molecular weight of the polyester-polyurethane may be 20000 to 80000, preferably 30000 to 70000. If the number average molecular weight is less than 20000, the adhesive strength is weak, and in particular, the heat resistance and the water resistance are weak, and there is a problem of being easily peeled off when contacted with hot water. There is a problem that is difficult to obtain.

The adhesive composition for laminated steel sheets of the present invention is prepared by adding a silane-modified epoxy resin, an epoxy silane, a phosphoric acid-modified ester resin, a crosslinking agent, a latent epoxy curing agent, an epoxy curing accelerator, and a block isocyanate to a polyester-polyurethane resin having crystallinity.

The adhesive composition for laminate steel sheets contains a silane-modified ring-opening epoxy resin. By adding this epoxy resin, adhesiveness with a steel plate, heat resistance, and boiling water resistance can be provided.

Since the silane-modified epoxy resin has been replaced by hydroxyl group by opening the epoxy functional group of the epoxy resin itself, it has more hydroxyl groups than general epoxy resin of the same molecular weight, so it is strongly adsorbed on the steel sheet to provide stronger adhesion, heat stability and boiling resistance. Grant.

The epoxy silane compound serves as an adhesion aid, and serves to improve adhesion and heat resistance of the adhesive layer. The epoxy functional group of the epoxy silane compound is easy to bond with the organic compound, and reacts with the curing agent to improve the strength of adhesion. The functional group attached to the silane may include a chlorine group, a methoxy group, an ethoxy group, a methacryloxy group, and the like, and the functional group is rapidly hydrolyzed upon heating to give strong adhesion through hydrogen bonding with a metallic material and an inorganic compound. Improve adhesive strength.

The epoxy silane compound may be included in an amount of 0.1 to 2 parts by weight, preferably 0.1 to 1 part by weight. If the content of the epoxy silane compound is less than 0.1 parts by weight, the adhesive strength is lowered or the silane compound is not properly exhibited. If the content of the epoxy silane compound is more than 2 parts by weight, the boiling resistance is lowered due to the property of hydrolysis. Indicates.

Phosphoric acid-modified ester resin is used to act as a plasticizer in order to improve the flexibility or processability of the adhesive, it is preferable to use a phosphite system here. Examples of the phosphite system include tri-cresyl phosphate (TCP), tri-2-ethyl hexyl phosphate (TOP), cresyl diphenyl phosphate (CDP), and tri-aryl phosphate (TAP).

The phosphoric acid modified ester resin may be included in an amount of 0.1 to 5 parts by weight, preferably 1 to 2 parts by weight. If the content of the phosphoric acid-modified ester resin is less than 0.1 parts by weight, there is a problem in adhesion, and if it exceeds 5 parts by weight, there is a problem in hot water resistance.

On the other hand, the phosphoric acid-modified polyester resin can be obtained by ester-reacting epoxy and phosphoric acid, the reaction temperature is 80 to 130 ℃, preferably at 110 ℃.

The crosslinking agent is added to the adhesive, and those having a -OH group at the terminal are used. What can be used as a crosslinking agent can use what has a molecular weight from a low molecular weight to an oligomer, and can use two or three functional groups. This is because the adhesive force is rather weak when the number of functional groups is large.

Here, as the crosslinking agent, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, tri Glycols such as methylene glycol and methyl propanediol may be used, and any of those having -OH groups at the terminal may be used as oligomers, such as synthesized isocyanate in a ratio of 1: 1/4 equivalent to the above-mentioned glycol.

The latent epoxy curing agent is added to improve the low temperature curing and adhesion performance of the adhesive composition, and the epoxy curing agent should be added to the latent curing agent because the urethane adhesive should be one-component type. In the medium / high temperature latent curing agent, the reaction may be performed at 100 ° C. or higher, and an amine adduct, dihydrazide, or dicyan diamine may be used. An amine adduct type or dihydrazide type can be used, More preferably, an amine adduct type can be used. Moreover, you may use the other epoxy latent hardener which has physical properties equivalent to these. The epoxy latent curing agent may be included in an amount of 0.01 to 1 parts by weight, and preferably 0.1 to 0.5 parts by weight, based on the total weight of the adhesive composition for the laminate steel sheet. At this time, when the content of the curing agent is less than 0.01 parts by weight or more than 1 part by weight, a problem occurs that the adhesive strength is lowered.

Since the curing accelerator should have the property that the adhesive strength should come out within 1 to 2 minutes in the process, it is added to promote the reaction of epoxy, and when the accelerator is added, the adhesion is greatly improved by gelling the epoxy more quickly. In general, accelerators used in curing amines may be phenol, alkylphenol, tertiary amine, etc., which are compounds having an -OH group, and mercaptanes having -SH groups are used as the low temperature and rapid curing accelerators. .

As the epoxy curing accelerator, imidazole is used, in particular, 2-methyl imidazole, 2-phenyl imidazole, 2-ethyl-4-methyl imidazole (2-ethyl-4 -methyl imidazole, 1-benzyl-2-methyl imidazole, 1-cyanoethyl-2-ethyl-4-methyl imidazole (1-cyanoethyl-2-ethyl-4 -methyl imidazole), 1-cyanoethl-2-methyl imidazole-trimellitate and 2-phenyl-4-methyl-5-hydroxymethyl imidazole (2 -phenyl-4-methyl-5-hydroxymethyl imidazole) can be used.

On the other hand, the epoxy curing accelerator may be included in 0.01 to 1 parts by weight, preferably from 0.05 to 0.1 parts by weight. If the content of the epoxy curing accelerator is less than 0.01 parts by weight, there is a curing rate problem, if it exceeds 1 part by weight may have a storage problem.

Block isocyanates include 4.4'-diphenylmethane diisocyanate, 2.6-dylene diisocyanate, 1.6-hexamethylene diisocyanate, isophorone diisocyanate, 4.4'-dicyclohexyl methane diisocyanate, 1.3-xylene diisocyanate, 1,4- Tetramethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,4-cyclohexanediisocyanate, toluene-2,6-diisocyanate, 1,5-naphthalene diisocyanate, 4-methoxy-1,3-phenyl Blocking dienedisocyanate, 4-chloro-1,3phenylenediisocyanate, 2,4-dimethyl-1,3-phenylenediisocyanate or a mixture thereof with a blocking agent such as 3.5-Dimethyl Pyrazole, Diethyl Malonate, Methylethyl keoxime, Caprolactan Ones may be used, and one or more may be mixed.

Here, the block isocyanate is blocked by dissociation temperature according to the blocking agent, and is blocked with 3,5-dimethylpyrazole, diethyl malonate and methyl ethyl ketoxime. And 3,5-dimethylpyrazole and diethyl malonic acid are used as blocking agents.

As a mixed solvent of an adhesive agent, any solvent with a boiling point of 70-150 degreeC can be used, Preferably the solvent which has a boiling point of 100-140 degreeC is preferable.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

< Example >

Manufacturing example  One: Polyol  Manufacture of A

200 parts by weight of terephthalic acid and 100 parts by weight of ethylene glycol were added to a stirrer, a thermometer, a column, a condenser and a four-necked flask, followed by dehydration and condensation at 220 ° C. The solution was heated to 150 ° C and dissolved. Subsequently, after dehydration condensation was carried out from 150 degreeC to 260 degreeC, it transesterified by 700 mmHg vacuum and synthesize | combined the terminal hydroxyl group containing polyester polyol. The acid value of the polyol obtained at this time was 3 mg / KOH, and the molecular weight was 2,000.

Manufacturing example  2: Polyol  Manufacture of B

300 parts by weight of terephthalic acid and 120 parts by weight of ethylene glycol were put in the same apparatus as in the preparation of polyol A, and dehydrated and condensed to 220 ° C. Then, 200 parts by weight of sebacic acid, 300 parts by weight of isophthalic acid and 300 parts by weight of neopentyl glycol were added. In the same manner, a terminal hydroxyl group-containing polyester polyol was synthesized. The acid value of the polyol obtained at this time was 3 mg / KOH, and the molecular weight was 2,000.

Manufacturing example  3: Polyol  Manufacture of C

250 parts by weight of terephthalic acid, 10 parts by weight of ethylene glycol, 150 parts by weight of neopentylglycol were added to the same device as in the preparation of polyol A, and dehydrated and condensed to 220 ° C. Was added, and the terminal hydroxyl group-containing polyester polyol was synthesized in the same manner as in Production Example 1. The acid value of the polyol obtained at this time was 3 mg / KOH, and the molecular weight was 2,000.

Manufacturing example  4: PU Preparation of -A

400 parts by weight of the polyester polyol A prepared in Preparation Example 1 in a stirrer, a thermometer, a condenser, a cooler, and a four-necked flask, and a mixed solvent (mixture of 1: 1 mixed with xylene and piacetate, "mixed solvent" 100 parts by weight was added and the mixture was dissolved by heating to 100 ° C. 10 parts by weight of 4,4 diphenyl methane diisocyanate (hereinafter referred to as "MDI") was added thereto, followed by reaction until the isocyanate peak of 2270 cm-1 disappeared by infrared spectroscopy while maintaining the reaction temperature of 80 to 100 ° C. Thereafter, MDI was further added in the same manner until the desired molecular weight was obtained, and the reaction was continued until the isocyanate peak of 2207 cm-1 disappeared while maintaining the reaction temperature of 90 to 110 ° C. Polyester solvent (PU-A) was prepared by adding a mixed solvent so that the solid content was 40%. The prepared PU-A had a solid content of 40%, a solution viscosity of 3,200 cps / 25 ° C, and a number average molecular weight of 50,000.

Manufacturing example  5: PU Preparation of -B

Polyurethane resin polyurethane polyol was prepared in the same manner as in Preparation Example 3, except that 360 parts by weight of polyester polyol A prepared in Preparation Example 1 and 40 parts by weight of polybutadiene diol were used instead of 400 parts by weight of polyester polyol A ( PU-B) was prepared. The prepared PU-B had a solid content of 40%, a solution viscosity of 3,300 cps / 25 ° C, and a number average molecular weight of 50,000. As polybutadiene diol, Poly-bd HT (1,4-trans 80% and 1,2-vinyl 20%, molecular weight 2,800) of Idemitsu Petrochemical Co., Ltd. was used.

Manufacturing example  6: PU Preparation of -C

Instead of the polyester polyol A, a urethane solution (PU-C) was prepared in the same manner as in Preparation Example 3 using the Polyester Polyol B prepared in Preparation Example 2. The prepared PU-C had a solid content of 40%, a solution viscosity of 3,300 cps / 25 ° C, and a number average molecular weight of 50,000.

Manufacturing example  7: PU Manufacture of D

Instead of polyester polyol A, the urethane solution (PU-D) was prepared in the same manner as in Preparation Example 3 using the Polyester Polyol C prepared in Preparation Example 3. The prepared PU-D had a solid content of 40%, a solution viscosity of 3,300 cps / 25 ° C, and a number average molecular weight of 50,000.

Manufacturing example  8: PU Manufacture of -E

The same method as in Preparation Example 3, except that 360 parts by weight of the polyester polyol A prepared in Preparation Example 1, 20 parts by weight of polybutadiene diol, and 20 parts by weight of polycarbonate diol were used instead of 400 parts by weight of polyester polyol A. Polyurethane resin polyurethane polyol (PU-E) was prepared. The prepared PU-E had a solid content of 40%, a solution viscosity of 3,300 cps / 25 ° C, and a number average molecular weight of 50,000.

Manufacturing example  9: Silane  Preparation of Modified Epoxy Resin

In a four-necked flask equipped with a stirrer, a thermometer and a condenser, 100 parts by weight of an epoxy equivalent of a bisphenol A type epoxy equivalent of 900 to 1000 and 40 parts by weight of ethyl acetate were added and dissolved at 80 ° C. To this, 7 parts by weight of 3-aminopropyltriethoxysilane were added and, upon complete stirring, benzyltriethylammonium chloride was added as a catalyst. The temperature was raised while paying attention to the exotherm, and the reaction was performed while maintaining the reaction temperature at 120 ° C for 3 hours. Thereafter, a vacuum reaction at 700 mmHg was carried out for 10 minutes under reduced pressure, followed by cooling to obtain 147 parts by weight of a mixed solvent to prepare a silane-modified epoxy composition.

Manufacturing example  10: Preparation of Phosphate Ester Resin

In a four-necked flask equipped with a stirrer, a thermometer, and a condenser, 90 parts by weight of epoxy resin of bisphenol A type having an epoxy equivalent of 900 to 1000 and 10 parts by weight of phosphoric acid were added and reacted at 90 ° C. Benzyltriethylammonium chloride was added as catalyst. The temperature was raised while paying attention to the exotherm, and the reaction was performed while maintaining the reaction temperature at 110 ° C for 3 hours. After the reaction was completed, the mixture was cooled to 100 parts by weight of a mixed solvent to prepare a silane-modified epoxy composition.

Example  1-6 and Comparative example  1-2

The silane-modified epoxy resin, epoxy silane, and phosphoric acid-modified polyester together with the polyester polyurethane resins (PU-A to PU-E) having crystallinity prepared in Production Examples 4 to 8 in the composition as shown in Table 1 below. A polyurethane adhesive composition was adjusted to 35% solids by using a resin, a crosslinking agent, a latent epoxy curing agent, an epoxy curing accelerator, an adhesion promoter, a block isocyanate, and a mixed solvent (mixing of xylene and piacetate in a 1: 1 ratio). . In Table 1, the content unit of each component is parts by weight.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 PU-A 100 - - - - 100 100 - PU-B - 100 - - - - - 100 PU-C - - 100 - - - - - PU-D - - - 100 - - - - PU-E - - - - 100 - - - Phosphoric Acid Ester Resin 2 2 2 3 1.5 2 6 2 Crosslinking agent 0.05 0.1 0.1 0.05 0.05 0.05 0.1 - Silane-Modified Epoxy Resin 2.5 5 5 2.5 5 5 0.5 5 Epoxy Silane (Coupling Agent) 0.5 One One 0.5 One One 0.1 One Latent epoxy curing agent 0.5 0.5 0.5 One 0.5 0.5 0.5 0.5 Epoxy curing accelerator 0.1 0.05 0.01 0.1 0.1 0.1 0.1 0.05 Block isocyanate 10 10 10 10 10 10 10 10 Mixed solvent 24 25 25 24 24 27 26 24 Solid content (%) 35 35 35 35 35 35 35 35 1. Dow Corning Products (Epoxysilane)
2. Ajinomoto fine Techno products (potential epoxy curing agent, epoxy curing accelerator)
3. Baxenden products (block isocyanates)

Experimental Method: Steel Sheet Specimen Example

The polyurethane adhesive compositions of Examples 1 to 6 and Comparative Examples 1 and 2 were applied to a steel sheet (EGI, GI, CR steel sheet) using a bar coater so as to be a combination as shown in Table 2 below, and the film was coated with a laminating machine. Adhesion specimens were prepared by adhering. At this time, the temperature of the steel sheet was 160 ~ 170 ℃ and the coating amount of the polyurethane adhesive was applied so as to be 4 ~ 7 g / ㎡ after drying.

division First film 2nd film Steel plate combinations 1 EGI Soft and Rigid Polyvinyl Chloride Films Steel plate combination 2 GI Soft and Rigid Polyvinyl Chloride Films Steel plate combination 3 CR Soft and Rigid Polyvinyl Chloride Films

The test plate for evaluating various properties of the adhesive agent and the adhesive of the present invention is bonded in an atmosphere of a steel sheet temperature of 160 ~ 170 ℃ at a tensile speed of 30 M / min, 2.5 kgf / cm 2 pressure, immediately put into a water bath immediately after lamination A laminated steel sheet was obtained. In addition, in order to stabilize the laminated steel sheet, the adhesive properties were measured with the specimens obtained after being left indoors for 2 hours.

Test Method 1: Adhesive Test Ericsen  Experiment)

As a test method to check the adhesion between the steel sheets (EGI, GI, CR) and the PVC layer, first, the width of 50 mm in the width of 5 mm on the surface of the specimen (PVC / AL foil / PET, PVC / PP / PET layer, etc.) / Cross cut with two rows of knives. The specimen is tested with an Ericsson tester by pushing the cross-cut area up to 6 mm deep at the speed of 5 to 20 mm / min from the back side to the surface to test for peeling between the disc and the PVC / PP / PET layer. At this time, the film cutting surface of the specimen should not be peeled off.

Test Method 2: Salt spray  Test

As a test method for measuring the degree of corrosion of the product, cross cut the film surface of the specimen with a sharp knife one by one horizontally and vertically, and then spray the 5% saline solution at a temperature of 35 ° C. for 90 minutes in the tester and observe the cross-cut area. . However, specimen cuts shall be tested after being completely sealed.

Test Method 3: Navigator  Test

As a test method for measuring the heat resistance of a product, the specimen is immersed in boiling water for 2 hours, then taken out and left for half a day before the surface is observed.

Test Method 4: Navigator  after Ericsen  exam

The specimen prepared in Test Method 3 was extruded 6 mm with an Eriksen tester under the same conditions as in the Ericsen test, and the peeling state of the film in the upper center portion was visually observed.

Test Method 5: cross  Cut test

In order to measure the adhesive strength between the film layer and the disc, the surface of the film layer is cut into a checkerboard shape 11 times at intervals of 1 mm with a razor blade.

Test Method 6: Heat Test

After the specimen prepared in the steel sheet specimen preparation example was left for 1 hour in a hot air oven at 150 ℃ after the Eriksen test, the peeling state of the film was visually observed.

Test criteria and results of adhesive properties

Evaluation of all adhesive properties was expressed by dividing into the following five steps. In addition, the test results are shown in Table 3.

◎: Very good, ◎ ~ ○: Excellent, ○: Good, △: Poor state

×: State very bad

division
Ericsen test Salt Water Spray Spray Test Navigability Test Ericsson Test After My Boiling Cross Cut Test Heat test Example 1 ◎ ◎ ○ ◎ ◎ ~ ○ ◎ ~ ○ Example 2 ◎ ~ ○ ◎ ◎ ~ ○ ○ ◎ ○ Example 3 ◎ ◎ ◎ ◎ ~ ○ ◎ ◎ ~ ○ Example 4 ◎ ◎ ◎ ~ ○ △ ◎ ~ ○ ○ Example 5 ◎ ◎ ◎ ~ ○ △ ◎ ○ Example 6 ◎ ◎ ◎ ◎ ◎ ◎ Comparative Example 1 ○ ◎ ~ ○ △ × ○ △ Comparative Example 2 ◎ ~ ○ ◎ ~ ○ ○ ○ ○ ◎

As shown in Table 3, Examples 1 to 6 according to the present invention is obtained by the normal addition of additives, excellent effects in Ericsen, saline solution portion, boiling resistance, boiling after Ericsen, cross-cut and heat test, etc. It can be seen that.

On the other hand, the adhesive composition of Comparative Example 1 is an excessive amount of phosphate ester resin is good results in the Eriksen test, but may cause problems in the heat-resistant side and forced peeling, the adhesive composition of Comparative Example 2 does not add a crosslinking agent Problems in terms of crosslinking density may cause problems in terms of heat resistance.

Although the technical spirit of the present invention has been described above, this is intended to exemplarily describe the best embodiment of the present invention, but not to limit the present invention. In addition, it is obvious that any person skilled in the art may make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (12)

Polyester-polyurethane resin having crystallinity; Silane-modified epoxy resins; Epoxy silanes; Phosphoric acid modified ester resins; Crosslinking agents; Latent epoxy curing agents; Epoxy curing accelerators; And block isocyanate; adhesive composition for a laminated steel sheet, comprising:
The method of claim 1,
The polyester polyurethane resin,
100 parts by weight of a polyester polyol having a molecular weight of 800 to 2500; And
5 to 15 parts by weight of isocyanate; Adhesive composition for a laminated steel sheet, characterized in that consisting of.
The method of claim 2,
The polyester polyol,
It is formed by synthesizing terephthalic acid and glycols to have crystallinity,
Adhesive composition for laminated steel sheets, characterized in that the acid value is 1 to 10 KOHmg / g.
The method of claim 1,
The polyester-polyurethane resin has a number average molecular weight of 20000 to 80000 adhesive composition for a laminated steel sheet.
The method of claim 1,
The silane-modified epoxy resin is an adhesive composition for a laminated steel sheet, characterized in that the epoxy equivalent of the epoxy equivalent of 400 to 6000g / eq by adding a silane coupling agent.
The method of claim 1,
The phosphoric acid-modified polyester resin adhesive composition for a laminated steel sheet, characterized in that the phosphite system.
The method of claim 1,
The crosslinking agent is a single molecule such as glycols, or
An adhesive composition for laminated steel sheets, which is an oligomer obtained by polyesterization.
The method of claim 1,
The latent epoxy curing agent is an adhesive composition for a laminated steel sheet, characterized in that at least one of the amine adduct (amine adduct), dihydrazide (dihydrazide) system and dicyandi diamine (DICY) system.
The method of claim 1,
The epoxy curing accelerator is 2-methyl imidazole, 2-phenyl imidazole, 2-ethyl-4-methyl imidazole, 1-benzyl 2-methyl imidazole, 1-cyanoethyl-2-ethyl-4-methyl imidazole, 1-sia 1-cyanoethl-2-methyl imidazole-trimellitate and 2-phenyl-4-methyl-5-hydroxymethyl imidazole (2-phenyl-4-methyl-5 -hydroxymethyl imidazole) at least any one of the adhesive composition for a laminated steel sheet.
The method of claim 1,
The block isocyanate is an adhesive composition for laminated steel sheet, characterized in that blocked with any one of 3,5-dimethylpyrazole, diethyl malonate and methyl ethyl ketoxime.
The method of claim 1,
Regarding the total weight of the total composition,
50 to 80 parts by weight of polyester-polyurethane resin;
1 to 10 parts by weight of the silane-modified epoxy resin;
0.1 to 2 parts by weight of epoxy silane;
0.1 to 5 parts by weight of phosphoric acid modified ester resin;
0.01 to 0.2 part by weight of a crosslinking agent;
0.01 to 1 part by weight of latent epoxy curing agent;
0.01 to 1 part by weight of an epoxy curing accelerator;
3 to 15 parts by weight of block isocyanate; And
20 to 40 parts by weight of a mixed solvent; adhesive composition for a laminated steel sheet comprising a.
12. The method of claim 11,
The adhesive composition for a laminated steel sheet is an adhesive composition for a laminated steel sheet, characterized in that the nonvolitile is 35%.