JP4357583B2 - Adhesive composition - Google Patents

Description

  The present invention relates to an adhesive composition having excellent adhesive strength, low odor, good workability, and environmental considerations.

  Although organic curable adhesives such as urethane resin adhesives, epoxy resin adhesives, and modified silicone resin adhesives, some types contain organic solvents, organic solvents can cause explosions and fires. For example, a type that does not contain an organic solvent is used. Since these adhesives do not contain a solvent, the viscosity tends to be high, and the coating workability is poor as it is, so the viscosity is adjusted by adding a relatively high boiling liquid compound called a diluent. ing.

On the other hand, there is also a negative effect due to the addition of a diluent, which may reduce adhesive strength, have an odor, or may be separated from the resin component. Patent Document 1 discloses a diluent having good compatibility with a urethane prepolymer, but there is room for improvement in adhesive strength and odor.
JP 2006-22298 A

  As another problem, since many adhesives use petroleum-derived raw materials, it is not certain whether these raw materials can be obtained continuously. Furthermore, when these adhesives are incinerated together with the adherend, carbon dioxide and the like are discharged, which is also a problem from the viewpoint of the global environment.

  An object of the present invention is to provide an adhesive composition such as a one-component moisture-curable urethane resin adhesive that has excellent adhesive strength, low odor, good workability, and is environmentally friendly. .

  The present invention is an adhesive composition comprising a 2-ethylhexyl ester compound of a fatty acid derived from vegetable oil, preferably rapeseed oil or soybean oil. The effect of the present invention is more prominently exhibited when the adhesive composition contains a urethane prepolymer, that is, in a one-component moisture-curing urethane resin adhesive.

  The adhesive composition of the present invention is particularly useful as an adhesive for on-site construction in which application is performed with a trowel or the like because the viscosity can be easily adjusted, so that the application workability is good, the adhesive strength is excellent, and the odor is small. In addition, because the raw material derived from vegetable oil is used, the carbon dioxide emitted during incineration is derived from the carbon dioxide taken into the plant during growth, and it is an adhesive that considers the global environment from the viewpoint of carbon neutrality. is there.

  The adhesive composition of the present invention contains a 2-ethylhexyl ester compound of a fatty acid derived from vegetable oil. Vegetable oils include linseed oil, sunflower oil, soybean oil, corn oil, peanut oil, cottonseed oil, sesame oil, rapeseed oil, olive oil, palm oil, coconut oil, castor oil and the like. Vegetable oil-derived fatty acids include cabrylic acid, cabric acid, lauric acid, myristylic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid, eicosenoic acid, behenic acid, erucic acid, lignoceric acid, etc. By converting these fatty acids into 2-ethylhexyl ester, a 2-ethylhexyl ester compound of fatty acid derived from vegetable oil can be obtained. What isolate | separated each fatty acid from vegetable oil may use the thing which 2-ethylhexyl-esterified, and what was 2-ethylhexyl-esterified with mixing each fatty acid may be used. The compounding amount of the 2-ethylhexyl ester compound of vegetable oil-derived fatty acid varies depending on the type and amount of other raw materials constituting the adhesive composition, the intended properties, etc., but preferably 5 to 5 for the entire adhesive composition. About 15% by weight is used.

  Examples of the resin component of the adhesive composition include urethane resin, epoxy resin, and modified silicone resin. A urethane prepolymer is used in a one-part moisture-curing urethane resin. The urethane prepolymer is obtained by a reaction between a compound having two or more active hydrogens such as polyol and a polyvalent isocyanate compound.

  Examples of the compound having two or more active hydrogens include polyether polyols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, polypropylene glycol, and adipine Examples include polyester polyols obtained by reacting acids, sebacic acid, terephthalic acid and the like with diols, polycarbonate polyols, polybutadiene polyols, polyisoprene polyols, and polyolefin polyols such as hydrogenated products thereof.

  As isocyanate compounds, 2,4′-diphenylmethane diisocyanate (2,4′-MDI), 4,4′-diphenylmethane diisocyanate (4,4′-MDI), polymeric diphenylmethane diisocyanate (p-MDI) tolylene diisocyanate, naphthalene In addition to aromatic polyfunctional isocyanates such as diisocyanate, aliphatic polyfunctional isocyanates such as hexamethylene diisocyanate and isophorone diisocyanate can be used.

  Various additives such as a filler such as calcium carbonate, a tackifier resin, a catalyst, a dehydrating agent, and an anti-aging agent may be added to the adhesive composition in the present invention as necessary.

  Hereinafter, based on an Example and a comparative example, this invention is demonstrated in detail. However, the present invention is not limited to the examples.

Method for synthesizing urethane prepolymer 1 After adding 300 parts by weight of TLM (manufactured by Toyokuni Oil Co., Ltd., average molecular weight 1500, product name), which is a trifunctional castor oil-modified polyol, into a separable flask, the mixture is stirred at 60 ° C. under reduced pressure for 2 hours. After that, 333 parts by weight of 4,4′-MDI was added and reacted for 2 hours at 80 ° C. in a nitrogen atmosphere to synthesize urethane prepolymer 1 having an NCO weight percentage of 12%.

Method for synthesizing urethane prepolymer 2 After 200 parts by weight of TLM, which is a trifunctional castor oil-modified polyol, was put into a separable flask and stirred at 60 ° C. for 2 hours under reduced pressure, 187.6 weight of 4,4′-MDI was added. A urethane prepolymer 2 having an NCO weight percentage of 10% was synthesized by reacting at 80 ° C. for 2 hours under a nitrogen atmosphere.

Example 1
M-300J (trade name, manufactured by Maruo Calcium Co., Ltd.), which is calcium carbonate, was added to 30 parts by weight of urethane prepolymer 1 and 1 part by weight of PTSI (trade name, manufactured by PCI) as a dehydrating agent in a planetary mixer. 36 parts by weight and 18 parts by weight of BF200 (trade name, manufactured by Bihoku Powder Chemical Co., Ltd.), which is calcium carbonate, were added and stirred for 30 minutes under reduced pressure. After stirring under reduced pressure, 10 parts by weight of Vedisol MO (trade name, manufactured by Kaneda Co., Ltd.), which is a 2-ethylhexyl ester compound of rapeseed oil-derived fatty acid, 44V20 (trade name, manufactured by Sumika Bayer Urethane Co., Ltd.), 7.5, polymeric MDI 1 part by weight, 0.1 part by weight of SCAT-1 (trade name, manufactured by Nitto Kasei Co., Ltd.), which is a tin-based catalyst, is stirred for 15 minutes under reduced pressure, and is a one-part moisture-curable urethane resin adhesive The adhesive composition of Example 1 was obtained. The viscosity was 16 Pa · s / 23 ° C. (BM type viscometer, No. 6 rotor, 20 rpm).

Examples 2-4
In Example 1, except having changed the compounding quantity of each compounding material as described in Table 1, it manufactured like Example 1, and obtained each adhesive composition of Examples 2-4.

Example 5
After 23 parts by weight of urethane prepolymer 2 and 1 part by weight of PTSI were put into a planetary mixer, 39 parts by weight of M-300J and 13 parts by weight of BF200 were added and stirred for 30 minutes under reduced pressure. After stirring under reduced pressure, 20 parts by weight of Vedisol MM (trade name) produced by 2-ethylhexyl ester compound of fatty acid derived from soybean oil, 10 parts by weight of 44V20, 0.1 part by weight of SCAT-1 were added, and the pressure was reduced. Was stirred for 15 minutes to obtain an adhesive composition of Example 5 which is a one-component moisture-curable urethane resin adhesive.

Comparative Examples 1-3
In Example 1, instead of using 10 parts by weight of Bezisol MO, diisononyl adipate (DINA) was used in the same manner as in Example 1 except that the blending amounts shown in Table 1 were used. Obtained.

Test method Each adhesive composition was applied to a flexible board using a comb-shaped iron (applying amount 550 g / m ² ), a wooden floor (adhesive surface was attached to a calp), and 1 in a 23 ° C., 50% RH atmosphere. After weekly curing, a plane tensile test was conducted at a tensile speed of 3 mm / min. Table 1 summarizes the results.

Each of the adhesive compositions of the examples has a viscosity of 20 Pa · s / 23 ° C. or less, and is thus excellent in applicability with a trowel or the like. Further, since the normal strength is 0.4 N / mm ² or more, the adhesion performance is also good. On the other hand, the adhesive composition of Comparative Example 1 using a conventional diluent has a high viscosity and is inferior in applicability. Further, in Comparative Examples 2 and 3 in which the viscosity is lowered by increasing the amount of the diluent, the normal strength is lowered.

Claims (2)

A one-component moisture-curable urethane resin adhesive composition comprising a vegetable oil-derived fatty acid 2-ethylhexyl ester compound and a urethane prepolymer . The one-component moisture-curable urethane resin adhesive composition according to claim 1, wherein the vegetable oil is rapeseed oil or soybean oil.