JP5454899B2 - Adhesive composition - Google Patents

Description

  The present invention relates to an adhesive composition for joining polyester members.

  Conventionally, polyvinyl chloride pipes (hereinafter referred to as “PVC pipes”) have been used for various pipes. However, since the PVC pipe contains chlorine, there is a risk of generating chlorine-based gas when incineration is performed after use, and therefore a special processing method has to be used at the time of processing. Therefore, in recent years, piping materials made of polyester resin such as polyethylene terephthalate (hereinafter referred to as “PET”) that do not contain chlorine in the resin and can be processed by a normal processing method have been proposed.

  As an adhesive for this polyester resin piping material, Patent Document 1 discloses a low-viscosity adhesive containing a polyurethane-based or modified silicone-based component containing a low-viscosity organic solvent.

  However, the joint between the pipe and the joint is usually larger at the joint outlet outlet inner diameter than the inner diameter of the receptacle or the outer diameter of the pipe is getting closer to the end. The tube may be pushed back by the elasticity of the resin. In particular, when a low-viscosity adhesive that does not dissolve or swell the resin is applied, this pushback is likely to occur. If the bonded portion is pushed back before the adhesive is cured, there is a problem that sufficient adhesive force cannot be exhibited and an accident due to poor bonding occurs.

JP 2006-103017 A

  In view of the above-described conventional problems, the present invention is an adhesive composition suitable for bonding a polyester resin member, in which at least one of them is bonded to a pipe and a joint made of polyester. It aims at providing the adhesive composition which makes it possible to suppress the pushing-back of a part.

As a result of researches to solve the above-mentioned problems, the present inventors have included an inorganic material that can be easily crushed at the time of joining a pipe and a joint, so that the inorganic material can be easily crushed at the time of joining. Thus, the present inventors have found that it is possible to suppress the push-back of the joint portion and have reached the present invention.
In other words, the present invention
(1) An adhesive composition for joining a pipe and a joint, at least one of which is made of polyester, comprising an adhesive and an inorganic substance (A) that is easily crushed when joining the pipe and the joint, The inorganic material (A) has a particle size in the range of 0.05 to 1 mm, and comprises 0.1 to 5 parts by weight of the inorganic material (A) with respect to 100 parts by weight of the adhesive composition. Agent composition,
(2) It is preferable that this inorganic substance (A) is calcium carbonate.
In (1) and (2) above,
(3) It is preferable that the adhesive is a one-component moisture curable polyurethane adhesive,
(4) The one-component moisture-curable polyurethane adhesive is preferably obtained by reacting a polyisocyanate (C) with a polyol (B) containing at least a polyoxyalkylene polyol and a polyester polyol. .
(5) A solvent (D) can be mix | blended with the said adhesive agent.

  By taking the above configuration, the inorganic substance blended in the adhesive composition is easily crushed at the time of joining, and has the effect of suppressing the pushing back of the pipe due to the elasticity of the resin that occurs at the time of joining the pipe and the joint.

Each component used in the adhesive composition of the present invention will be described in detail below.
As the adhesive in the present invention, polyurethane, modified silicone, epoxy and the like can be used as long as they exhibit an effective adhesive force with respect to the polyester resin. Furthermore, the one-component moisture-curable polyurethane adhesive obtained by reacting the polyol (B) containing at least a polyoxyalkylene polyol and a polyester polyol with the polyisocyanate (C) has a thick adhesive layer. It is preferable because it exhibits a high adhesive strength.

  Next, the inorganic substance (A) component that is easily crushed when the pipe and the joint used in the present invention are joined will be described. Here, “Easily crushed when joining the pipe and the joint” means that when the pipe is pushed into the joint and joined, it is crushed by pushing with a normal human force that does not damage the pipe and the joint. Say. This inorganic substance (A) is crushed between the pipe and the joint when the pipe and the joint are joined, and acts as a slip stopper, thereby preventing pushback when the pipe and the joint are joined. Examples of the inorganic substance (A) that can be easily crushed at the time of joining the pipe and the joint include calcium carbonate, diatomaceous earth, calcined clay, clay, talc, bentonite, shirasu balloon, and glass balloon. Of these, calcium carbonate is preferred. Moreover, it is preferable that a particle size is 0.05-1.0 mm, and it is further preferable that a particle size is 0.2-0.6 mm. Moreover, 0.1-5 weight part is preferable with respect to 100 weight part of adhesive compositions, and, as for the usage-amount, 1-3 weight part is more preferable.

  Next, the polyol (B) component in the one-component moisture-curable polyurethane adhesive suitably used in the present invention will be described. The polyol (B) contains at least a polyoxyalkylene polyol and a polyester polyol.

  Examples of the polyoxyalkylene polyol include a polymer obtained by ring-opening addition polymerization of alkylene oxide, and a polymer obtained by ring-opening addition polymerization of alkylene oxide with an initiator. Initiators include low-molecular-weight compounds such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, and shoelacese. Examples thereof include alcohols, polyhydric phenols such as bisphenol A, low molecular polyamines such as ethylenediamine, low molecular amino alcohols such as diethanolamine, or a mixture of two or more thereof. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, or a mixture of two or more thereof. That is, the polyoxyalkylene polyol is a polyoxyalkylene polymer containing two or more hydroxyl groups in the molecule. Specifically, for example, polyoxyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol , Poly (oxyethylene) -poly (oxypropylene) -glycol and poly (oxyethylene) -poly (oxybutylene) -glycol, among which polyoxypropylene glycol is particularly preferred. In the present invention, the polyoxyalkylene polyol has a number average molecular weight of 500 to 40,000, more preferably 2,000 to 30,000, particularly 10 from the viewpoint of lowering the viscosity of the curable composition and high elongation of the cured product. The average number of hydroxyl groups per molecule is preferably 2 to 8, particularly preferably 2 to 4, and the total degree of unsaturation is 0.07 (meq / g) or less. In particular, a narrow molecular weight distribution of 0.04 (meq / g) or less is preferable.

  Examples of the polyester polyol include one or more of polycarboxylic acids such as adipic acid, sebacic acid, terephthalic acid, hexahydroterephthalic acid and trimellitic acid, acid esters, acid anhydrides, ethylene glycol, 1,3 -Propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, glycerin, trimethylolpropane, pentaerythritol, etc. Polyester polyol or polyester amide polyol obtained by dehydration condensation reaction with one or more of low molecular weight alcohols, low molecular weight amines such as hexamethylenediamine and xylylenediamine, and low molecular weight amino alcohols such as monoethanolamine. Ol. Also, for example, lactone polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular alcohols, low molecular amines, and low molecular amino alcohols as initiators. And polycarbonate polyol. Of these, polycarbonate polyol is preferred because of its good water resistance, adhesion and the like. The content ratio of the polyoxyalkylene polyol and the polyester polyol is preferably 1 to 30 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the polyoxyalkylene polyol. When the content ratio of the polyester polyol with respect to 100 parts by weight of the polyoxyalkylene polyol is less than 1 part by weight, the adhesive strength is remarkably reduced, and when it exceeds 30 parts by weight, workability and water resistance are lowered. In addition, polyolefin polyols, acrylic polyols, animal and plant polyols, copolyols thereof, and the like can be used as the polyol (B) component.

  Next, the polyisocyanate (C) component used in the present invention will be described. Examples of the polyisocyanate (C) include toluene diisocyanate (TDI), phenylene diisocyanate, diphenyl diisocyanate, naphthalene diisocyanate, diphenyl ether diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (polymeric MDI), and mixtures thereof. Aliphatic polyisocyanates such as aromatic aliphatic polyisocyanates such as hexamethylene diisocyanate, pentamethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, cyclohexane diisocyanate, methylene bis (cyclohexyl isocyanate), isophorone diisocyanate Further adduct modified products of these organic polyisocyanates, biuret modified products, isocyanurate modified product, uretonimine modified product, uretdione modified product include modified polyisocyanates such as carbodiimide modified products. Of these, aromatic polyisocyanates are preferable, and toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) are more preferable. These can be used alone or in admixture of two or more.

  Next, the solvent (D) component that can be used in the present invention will be described. Examples of the solvent (D) include ester solvents such as ethyl acetate, ketone solvents such as methyl ethyl ketone, aliphatic solvents such as n-hexane, alicyclic solvents such as cyclohexane, and aromatic solvents such as toluene and xylene. Any known organic solvent that does not react with the curing component of the adhesive can be used alone or in admixture of two or more. Of these, ethyl acetate is preferred when used in a one-component moisture-curable polyurethane adhesive.

In the adhesive of the present invention, additives such as a curing accelerating catalyst, a filler, a colorant, a thixotropic agent, and an adhesiveness imparting agent can be used as necessary.
Examples of the curing accelerating catalyst include organic tin compounds such as tin 2-ethylhexanoate, dibutyltin dilaurate, dibutyltin bisacetate and dibutyltin bisacetylacetonate, and tertiary amines such as triethylenediamine and N-ethylmorpholine. Kind. Among these, when used for a one-component moisture-curable polyurethane adhesive, an organometallic catalyst having an organic tin compound as a representative example is preferable. The amount of the curing accelerating catalyst used is preferably 0.005 to 10 parts by weight, more preferably 0.1 to 2 parts by weight, with respect to 100 parts by weight of the isocyanate group-terminated urethane prepolymer.

  As the filler, in addition to the inorganic component (A), for example, calcium carbonate, fatty acid-treated calcium carbonate, fumed silica (colloidal silica), precipitated silica, anhydrous silicic acid, hydrous silicic acid, magnesium carbonate, diatomaceous earth, Baked clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, zinc oxide, activated zinc white, shirasu balloon, glass balloon, wood powder, pulp, cotton chip, mica, walnut shell powder, rice husk powder And powdery fillers such as graphite, fine aluminum powder and flint powder, and fibrous fillers such as asbestos, glass fiber, glass filament, carbon fiber, Kepler fiber and polyethylene fiber.

Examples of the adhesion imparting agent include a coupling agent such as a silane coupling agent.
Examples of the colorant include inorganic pigments such as iron oxide, chromium oxide, and titanium oxide, and organic pigments such as phthalocyanine blue and phthalocyanine green.
Examples of the thixotropic agent include fatty acid-treated calcium carbonate (also mentioned as a filler), hydrogenated castor oil, calcium stearate, zinc stearate, and colloidal silica.
In the adhesive of the present invention, each additive component can be used alone or in combination of two or more.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further in detail, it is not limited to this.

[Synthesis Example 1]
In a warming reaction vessel equipped with a stirrer, thermometer, nitrogen seal tube and cooler, under a nitrogen gas stream, 390 g of ethyl acetate, polyoxypropylene triol (actol T-4000, Mitsui Chemicals, number average molecular weight 4, 000) 479 g and 63 g of polycarbonate diol (Nipporan 980N manufactured by Nippon Polyurethane Industry Co., Ltd., hydroxyl value 56.1), and a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (T manufactured by Nippon Polyurethane Industry Co., Ltd.). -80, mixing ratio: 2,4-isomer / 2,6-isomer = 8/2, molecular weight 174) 66 g and zirconium octylate 0.05 g were gradually added with stirring and stirred at 70-80 ° C. for 1 hour. When the isocyanate group content falls below the theoretical value, the reaction is terminated, and the isocyanate group-containing urethane The prepolymer U-1 was synthesized. The measured isocyanate group content by titration of this isocyanate group-containing urethane prepolymer was 1.3% by mass, and the viscosity was 7,000 mPa · s / 25 ° C.

  In a mixing vessel equipped with a stirrer and a nitrogen seal tube, 100 g of an isocyanate group-containing urethane prepolymer U-1 was charged under a nitrogen gas stream. In this, 22 g of ethyl acetate and calcium carbonate (manufactured by Hitachi Crushed Stone Co., Ltd. 2.4 g (particle diameter 0.3 to 0.5 mm) was gradually added with stirring to prepare an adhesive composition.

[Comparative Example 1]
In Example 1, an adhesive composition was prepared in the same manner except that calcium carbonate was not used.

[Comparative Example 2]
An adhesive composition was prepared in the same manner except that the amount of calcium carbonate added in Example 1 was 12 g.

[Comparative Example 3]
An adhesive composition was prepared in the same manner except that the calcium carbonate added in Example 1 was Whiten B (manufactured by Shiraishi Calcium Co., Ltd., average particle size 3.6 μm).

<Push-back measurement test>
Using a straight pipe made of PET (Showa Denko Construction Materials Co., Showa Eco Pipe 100A) and a PET fitting (Showa Denko Construction Materials Co., Showa Eco Pipe Fitting EPDS100) adjusted for 1 day under conditions of 23 ° C. and 55% relative humidity Then, the sample well stirred in the container was applied to the joint receiving port and the straight pipe, and the straight pipe was inserted into the joint receiving port to a position corresponding to the stopper. After holding for 30 seconds, the distance at which the straight pipe was pushed back after 1 minute was measured.
Table 1 shows the results of the push-back measurement test using Example 1 and Comparative Examples 1 to 3.
From the results of Example 1 and Comparative Examples 1 to 3, it was confirmed that pushing back of the joint portion is suppressed by adding an appropriate amount of calcium carbonate having an appropriate particle diameter.

Claims (6)

At least one of an adhesive composition for bonding the pipe and the joint is made of polyester, containing an adhesive, and easily crumble inorganic during bonding of the tube and the joint (A), the inorganic substance (A ) Is selected from calcium carbonate, diatomaceous earth, calcined clay, clay, talc, bentonite, shirasu balloon and glass balloon, the inorganic substance (A) has a particle size in the range of 0.05 to 1 mm, and the inorganic substance (A) An adhesive composition comprising 0.1 to 5 parts by weight per 100 parts by weight of the adhesive composition.   The adhesive composition according to claim 1, wherein the inorganic substance (A) is calcium carbonate.   The adhesive composition according to claim 1 or 2, wherein the adhesive is a one-component moisture-curing polyurethane adhesive.   The one-component moisture-curable polyurethane-based adhesive is obtained by reacting a polyol (B) containing at least a polyoxyalkylene polyol and a polyester polyol with a polyisocyanate (C). Adhesive composition.   The adhesive composition according to any one of claims 1 to 4, wherein the adhesive contains a solvent (D). A method of joining a pipe and a joint, at least one of which is made of polyester, using an adhesive composition, wherein the adhesive composition is 0.1% relative to 100 parts by weight of the adhesive and the adhesive composition. -5 parts by weight of an inorganic substance (A), wherein the inorganic substance (A) is selected from calcium carbonate, diatomaceous earth, calcined clay, clay, talc, bentonite, shirasu balloon and glass balloon, A granular material having a particle diameter of 0.05 to 1 mm that can be easily crushed when the joint is joined. After the method is applied to the pipe and the joint, the adhesive composition is coated with the inorganic material (A) in the adhesive composition. Pushing the tube into the joint with a force such that at least a portion of the tube breaks.