JP2018076388A - Seal member and seal member manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal member high in cut-off performance.SOLUTION: A coated film is formed on a surface of a substrate consisting of elastic deformable isolated cells by a raw material consisting of an urethane prepolymer having at least one of an allyl ether group, a vinyl ether group, an acrylate group as a terminal functional group, and polythiol having a thiol group. The urethane prepolymer having the terminal functional group and the polythiol having the thiol group are cured with generation of an ene-thiol reaction between the terminal functional group and the thiol group by irradiation of light to provide a coated film. The coated film has high cut-off performance and low compressive permanent set. Therefor a seal member high in effect can be achieved by forming the coated film on a surface of the elastic deformable substrate.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a seal member including an elastically deformable base and a coating formed on at least a part of the surface of the base, and a method for manufacturing the seal member.

  In architecture, civil engineering, electronics, automobiles, and the like, processing such as water stop, heat insulation, and sound absorption is performed by filling the gaps between the respective members in a compressed state. As such a sealing member, a synthetic resin foam, a rubber foam or the like is generally used. Since the foam has an appropriate elastic force, it can follow and adhere to the irregularities on the surface of the member to be sealed, and exhibits excellent sealing properties. Further, in order to ensure further sealing performance, as described in the following patent document, a seal having a film formed on at least a part of the surface of an elastically deformable substrate such as a synthetic resin foam or rubber foam Development of materials is underway.

Japanese Patent No. 4602280 Japanese Patent No. 5746622 JP 2006-83236 A

  The present invention has been made in view of the above points, and has an object to provide a water-stopping sealing material that has sufficient adhesion between the surface coating provided on the surface of the foam and the foam and has a high water-stopping property. To do. In particular, it is an object of the present invention to provide a water-stopping sealing material having a high water-stopping property comprising a surface coating that adheres to and adheres to the irregularities on the surface of the member to be sealed, and a foam of closed cells.

  The sealing member of the present invention comprises a base composed of elastically deformable closed cells, a urethane prepolymer having at least one of an allyl ether group, a vinyl ether group and an acrylate group as a terminal functional group, and a polythiol having a thiol group. And a film formed on at least a part of the surface of the substrate.

  The sealing member manufacturing method of the present invention can elastically deform a raw material comprising a urethane prepolymer having at least one of an allyl ether group, a vinyl ether group and an acrylate group as a terminal functional group, and a polythiol having a thiol group. A sealing member is manufactured by a photopolymerization reaction, which includes an attaching step for attaching to at least a part of the surface of the substrate and an irradiation step for irradiating light to the raw material attached in the attaching step.

  According to the seal member and the seal member manufacturing method of the present invention, it is possible to provide a seal member having a high water-stopping property.

It is a side view which shows the instrument for evaluating the water stop property of a sealing member. It is a top view which shows the instrument for evaluating the water stop of a sealing member. In the table | surface which shows the physical property evaluation of the compounding quantity (part by weight) of the prepolymer as a raw material of the film | membrane of the sealing member of Examples 1-6, the polythiol (molar ratio) as a raw material, and the sealing member of Examples 1-6. is there. In the table | surface which shows the physical property evaluation of the compounding quantity (part by weight) of the prepolymer as a raw material of the film | membrane of the sealing member of Examples 7-12, the polythiol (molar ratio) as a raw material, and the sealing member of Examples 7-12. is there. It is a table | surface which shows the raw material of the film | membrane of the sealing member of Comparative Examples 1-3, and the physical-property evaluation of the sealing member of Comparative Examples 1-3. It is the table | surface which shows the physical property evaluation of the compounding quantity (part by weight) of the prepolymer as a raw material of the film | membrane of the sealing member of Comparative Examples 4-8, the polythiol (molar ratio) as a raw material, and the sealing member of Comparative Examples 4-8. is there. It is a table | surface which shows the compounding quantity (weight part) of the raw material for manufacturing the prepolymer AD shown to FIG. It is a table | surface which shows the compounding quantity (weight part) of the raw material for manufacturing the prepolymers EH shown to FIG.

  The “seal member” according to the present invention includes an elastically deformable substrate, a urethane prepolymer having at least one of an allyl ether group, a vinyl ether group, and an acrylate group as a terminal functional group, and a polythiol having a thiol group. And a film formed on at least a part of the surface of the substrate.

  In addition, the “seal member manufacturing method” described in the present invention includes a raw material comprising a urethane prepolymer having at least one of an allyl ether group, a vinyl ether group, and an acrylate group as a terminal functional group, and a polythiol having a thiol group. The sealing member is manufactured by a photopolymerization reaction, including an attaching step of attaching to at least a part of the surface of the elastically deformable substrate and an irradiation step of irradiating the raw material attached in the attaching step with light.

  Examples of the elastically deformable substrate include rubber foam and synthetic resin foam. For example, rubber sponge, polyurethane foam, polyolefin foam and the like can be mentioned. Especially, the foam film of a foam breaks or penetrates, and since it will be in a communication state, the possibility that water will ooze out is high, and a rubber sponge made of closed-cell foam and a polyolefin foam are preferred.

  Further, a urethane prepolymer having at least one of an allyl ether group, a vinyl ether group and an acrylate group as a terminal functional group is obtained by adding an allyl ether group, a vinyl ether group and an acrylate group to a urethane prepolymer synthesized from a polyol and a polyisocyanate. And a compound having at least one of Incidentally, if the weight average molecular weight of the urethane prepolymer is too high or too low, the followability of the coating to the substrate is deteriorated. For this reason, it is preferable that the weight average molecular weights of the said urethane prepolymer are 1000-30000. Furthermore, it is preferable that it is 1500-25000.

  The “polyisocyanate” used for the synthesis of the urethane prepolymer is a compound having two or more isocyanate groups in one molecule, and may be any compound that is usually employed as a raw material for the urethane prepolymer. For example, aromatic isocyanate, aliphatic isocyanate, alicyclic isocyanate, etc. are mentioned. Examples of the aromatic isocyanate include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), polymeric MDI (crude MDI), xylylene diisocyanate, 1,5-naphthalene diisocyanate, and the like. Examples of the aliphatic isocyanate include hexamethylene diisocyanate, isopropylene diisocyanate, and methylene diisocyanate. Examples of the alicyclic isocyanate include cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate (hydrogenated MDI), and the like. A combination of one or more of these various polyisocyanates can be used as a raw material for the urethane prepolymer.

  The “polyol” used for the synthesis of the urethane prepolymer is a compound having two or more hydroxyl groups in one molecule, and may be any compound that is usually employed as a raw material for the urethane prepolymer. For example, a polyester polyol, a polyether polyol, etc. are mentioned. Some polyester polyols are obtained by a condensation reaction between a polyhydric alcohol and a polycarboxylic acid. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, butanediol, butylene glycol, glycerin, trimethylolpropane, and the like, and these can be used alone or in combination of two or more. Examples of the polyvalent carboxylic acid include glutaric acid, adipic acid, maleic acid, terephthalic acid, and isophthalic acid, and these can be used alone or in combination of two or more. Furthermore, the polyester polyol obtained by ring-opening condensation of caprolactone, methylvalerolactone, etc. is mentioned.

  Examples of polyether polyols include addition polymerization of oxides such as ethylene oxide, propylene oxide, trimethylene oxide, and butylene oxide to polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, glycerin, trimethylolpropane, and sorbitol. Can be mentioned. It is possible to use one or a combination of two or more of these various polyols as a raw material for the urethane prepolymer.

  Moreover, it is preferable to use a catalyst in the synthesis | combination of the said urethane prepolymer. The catalyst is not particularly limited as long as it is normally employed as a raw material for the urethane prepolymer, and examples thereof include amine-based catalysts and organometallic catalysts. Examples of the amine catalyst include triethylenediamine, diethanolamine, dimethylaminomorpholine, N-ethylmorpholine, and the like. Examples of the organometallic catalyst include star octoate, dibutyltin dilaurate, lead octenoate, potassium octylate and the like. A combination of one or more of these various catalysts can be used as a raw material for the urethane prepolymer.

  The compound having at least one of allyl ether group, vinyl ether group, and acrylate group to be added to the synthesized urethane prepolymer may be any compound that can be added to the isocyanate group of the urethane prepolymer. , Hydroxyethyl allyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyethyl acrylate and the like. In order to increase the reaction activity, a monofunctional active hydrogen compound is preferable, and it is preferable that the double bond is in the vicinity of both ends of the polymer.

  Examples of the polythiol that undergoes an enethiol reaction with the urethane prepolymer include esters of mercaptocarboxylic acid and a polyhydric alcohol, aliphatic polythiols, and aromatic polythiols. Examples of the aliphatic polythiol and aromatic polythiol include ethanedithiol, propanedithiol, hexamethylenedithiol, decamethylenedithiol, tolylene-2,4-dithiol, xylenedithiol and the like.

  In the ester of mercaptocarboxylic acid and polyhydric alcohol, examples of mercaptocarboxylic acid include thioglycolic acid and mercaptopropionic acid, and examples of polyhydric alcohol include ethylene glycol, propylene glycol, 1,4-butanediol, , 6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, sorbitol and the like. Among these, an ester of a mercaptocarboxylic acid and a polyhydric alcohol is preferable in terms of low odor. Specifically, for example, trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3 -Mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate), dipentaerythritol hexa (3-mercaptopropionate). In addition, it is possible to use what used together 1 type, or 2 or more types of those various polythiols as a raw material of enethiol reaction with the said urethane prepolymer.

  The urethane prepolymer having at least one of the above-mentioned allyl ether group, vinyl ether group and acrylate group as a terminal functional group and polythiol are mixed and irradiated with light, whereby at least one of the surface of the substrate is obtained by the enethiol reaction. It is possible to form a film on the part. Moreover, it is possible to form a highly water-resistant film by using a thiol having an average functional group number of 2 or more as the polythiol described above. This film preferably has an elongation measured according to JISK6400 of 70% or more. The upper limit of the elongation of the film is not particularly limited, but is usually 250%, particularly 200%. Accordingly, the elongation is preferably 70 to 250%, particularly 100 to 200%. If the elongation is less than 70%, the flexibility of the seal member is reduced, or cracks or the like are generated in the creep state, and water leaks particularly from the interface between the seal member and the close contact surface. On the other hand, it is sufficient if the elongation is 250%, particularly 200%, and if it exceeds 250%, it is too flexible, and even if a slight stress is applied, there is a risk of water leakage, which is not preferable.

  The amount of the thiol group that is reacted with the urethane prepolymer having at least one of an allyl ether group, a vinyl ether group, and an acrylate group as a terminal functional group is the allyl ether group, vinyl ether group, and acrylate group of the urethane prepolymer. The ratio of the total number of equivalents of all thiol groups to the total number of equivalents of at least one (ene / thiol ratio) is preferably 0.7 to 2.5. If the ene / thiol ratio is too large or too small, there is a possibility that the water stoppage may be lowered.

  Further, in order to effectively perform a photopolymerization reaction between at least one of allyl ether group, vinyl ether group, and acrylate group added to the urethane prepolymer and a thiol group, the blending raw material may contain a photopolymerization initiator. Is possible. Examples of the photopolymerization initiator include acetophenone-based, benzophenone-based, and thioxanthone-based compounds. As the acetophenone series, for example, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 4- (1-t-butyldioxy-1-methylethyl) acetophenone, 2-methyl-1- [4- (Methylthio) phenyl] -2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, diethoxyacetophenone, 2-hydroxy-2-methyl- 1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1 -[4- (1-Methylvinyl) phenyl] propanone oligomer And the like.

  Examples of the benzophenone series include 4- (1-t-butyldioxy-1-methylethyl) benzophenone, 3,3 ′, 4,4′-tetrakis (t-butyldioxycarbonyl) benzophenone, and methyl o-benzoylbenzoate. 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3 ', 4,4'-tetra (t-butylperoxylcarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, 4- Examples include benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium chloride, and the like. Examples of the thioxanthone series include 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichloro. Examples include thioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy) -3,4-dimethyl-9H-thioxanthone-9-one mesochloride.

  The content of the photopolymerization initiator is preferably 0.01 to 5 parts by weight per 100 parts by weight of the urethane prepolymer, and more preferably 0.1 to 3 parts by weight. If the content of the photopolymerization initiator is too small, the photopolymerization initiation ability is insufficient, and the raw material is not rapidly polymerized, which is not preferable. On the other hand, if the content of the photopolymerization initiator is too large, polymerization is excessively promoted, the crosslinking density becomes too high, or the crosslinked structure is formed unevenly, which is not preferable.

  In addition, when a sealing member is formed using a raw material in which a urethane prepolymer having at least one of the above-mentioned allyl ether group, vinyl ether group, and acrylate group as a terminal functional group and polythiol is formed, the permeability is formed. The mixed raw material is applied with a predetermined film thickness on a good film or the like. Next, an elastically deformable substrate is pressure-bonded onto the applied mixed raw material. At this time, the liquid raw material is appropriately adapted to the surface of the substrate. Then, in the presence of air, the applied mixed raw material is irradiated with ultraviolet rays from below the film, whereby the mixed raw material is cured and a film is formed. As a result, the raw material is cured while the liquid raw material and the surface of the base body are appropriately blended, thereby improving the adhesion between the base body and the film.

  As the elastically deformable substrate, when a substrate of a predetermined material, specifically, for example, a substrate made of ethylene propylene diene rubber (EPDM) is adopted, a primer treatment is applied to the adhesion surface of the substrate to the mixed raw material. By performing this, it becomes possible to ensure the adhesion between the substrate and the film. Examples of the primer treatment include blast treatment, chemical treatment, degreasing, flame treatment, oxidation treatment, steam treatment, corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, ion treatment and the like.

Moreover, it is preferable that the irradiation amount of the ultraviolet-ray at the time of hardening a mixed raw material is 600-1800 mJ / cm < ² > (365 nm integrated light quantity). Moreover, when apply | coating a mixed raw material to a film, it is preferable to use coating apparatuses, such as a comma coater, a die coater, and a gravure coater. In particular, a die coater is preferably used because the viscosity of the viscous fluid can be adjusted by adjusting the temperature of the viscous fluid during application.

  With respect to the sealing member manufactured by the above method, the water-stopping property was evaluated using the instrument 10 shown in FIGS. 1 and 2. FIG. 1 is a side view of the instrument 10, and FIG. 2 is a plan view showing the instrument 10 from a viewpoint from above. The instrument 10 includes a base 20, a steel plate 22, a spacer 24, an acrylic plate 26, and an adapter 28. The steel plate 22 is obtained by applying a polyester resin and a melamine resin paint (Neo-Amilak 6000 manufactured by Kansai Paint Co., Ltd.) to the surface of an iron plate having a thickness of 1 mm, and is placed on the upper surface of the base 20. Spacers 24 having a thickness of 2.5 mm are placed at the four corners of the upper surface of the steel plate 22. Then, the test sample 30 of the seal member is placed on the upper surface of the steel plate 22, and the acrylic plate 26 is placed on the upper surface of the test sample 30.

  As the test sample 30, an annular seal member having an outer diameter of 60 mm, an inner diameter of 40 mm, and a thickness of 5 mm is used. Specifically, first, a seal member having a thickness of 5 mm is manufactured by the above-described method, and a double-sided tape (Nitto Denko No. 500) is attached to the surface opposite to the coating surface of the seal member. Next, the test sample 30 is obtained by punching out the sealing member to which the double-sided tape is attached into an annular shape having an outer diameter of 60 mm and an inner diameter of 40 mm. The test sample 30 is placed on the steel plate 22 with the coating of the test sample 30 in close contact with the steel plate 22 side and the double-sided tape facing upward. Then, the acrylic plate 26 is placed on the test sample 30, and the steel plate 22 and the acrylic plate 26 are sandwiched so that the test sample 30 is compressed to the thickness of the spacer 24 (2.5 mm). That is, the test sample 30 is compressed to 50% (2.5 mm / 5 mm). A through hole 32 is formed in the acrylic plate 26 so as to penetrate the annular shape of the test sample 30 compressed by the steel plate 22 and the acrylic plate 26, and the adapter 28 is connected to the through hole 32. Has been.

  Then, in a state where the test sample 30 is compressed by the steel plate 22 and the acrylic plate 26, the test sample 30 is left in a constant temperature and humidity chamber at 23 ° C. for 65 hours. Thereafter, distilled water is supplied into the annular shape of the test sample 30 via the adapter 28, and the annular shape of the test sample 30 is filled with distilled water. Then, 5 KPa of air is supplied to the inside of the test sample 30 filled with distilled water via the adapter 28 and maintained in that state for 5 minutes, and then water leakage to the outside of the test sample 30 is prevented. The presence or absence is confirmed visually. If there is no water leakage to the outside of the test sample 30, 5 kPa air is further supplied to the inside of the test sample 30 via the adapter 28 and maintained in that state for 5 minutes. The presence or absence of water leakage to the outside of the sample 30 is confirmed visually. At this time, when there is no water leak to the outside of the test sample 30, the supply of 5 KPa air and the confirmation of the water leak after being maintained in that state for 5 minutes are repeated. In this way, the presence or absence of water leakage to the outside of the test sample 30 is confirmed, and when there is no water leakage when 50 KPa of air is supplied to the inside of the test sample 30, it is used as the test sample 30. The seal member is judged to have good water-stopping properties. The evaluation test is performed on two types of test samples 30, that is, a seal member using a natural rubber foam as a base and a seal member using an EPDM foam as a base.

In addition, since the seal member is used in a compressed state in the gaps between the members, if the film of the seal member is compressed and there is little distortion after the compression is released, long-term water stopping properties can be ensured. It is assumed. For this reason, the compression set (%) of the coating film of the sealing member was measured based on JIS K 7312: 1996. Specifically, compression set (%) was measured according to the following conditions.
Test piece: Cylindrical film of t12.5 mm × φ29 mm Test condition: After 22 hours at 70 ° C. in a compressed state of 25%, the compression is released and left to stand at 23 ° C. for 30 minutes. Cooling compression set = {( t ₀ −t ₁ ) / (t ₀ −t ₂ )} × 100
t ₀ ; Thickness before compression of test piece t ₁ ; Thickness after cooling of test piece t ₂ ; Thickness of spacer Note that the compression set (%) is preferably 20% or less. For example, it is preferably 15% or less.

  The sealing member of the present invention can be used not only for water stopping but also for dustproofing, heat insulation, soundproofing, vibration proofing, buffering and airtightness. For example, it can be used as a dustproof material, a heat insulating material, a soundproofing material, a vibration proofing material, a shock absorbing material, a filler, or the like. In particular, it is a module component that constitutes a vehicle lamp, and is suitable as a sealing material for sealing the lamp and the housing.

  The following examples illustrate the present invention more specifically. However, the present invention is not limited to this embodiment, and can be implemented in various modes with various modifications and improvements based on the knowledge of those skilled in the art.

<Raw material and production of seal member>
From the raw materials having the formulations shown in FIGS. 3, 4, and 6, the seal member films of Examples 1 to 12 and the seal member films of Comparative Examples 4 to 8 were produced. Below, the detail of each raw material is shown.

  Each of the “prepolymers” shown in FIG. 3, FIG. 4 and FIG. 6 is obtained by reacting the raw materials having the blending (weight ratio) shown in FIG. 7 or FIG. 8 according to the following method.

  First, an amount shown in the figure is added to a 1 liter separable flask, and the amount shown in the figure is added while stirring the polyol while flowing nitrogen. After confirming that the contents are uniform, a catalyst (0.3 g of dibutyltin dilaurate (DBTDL)) is added. And it heats up slowly so that it may become 80-90 degreeC over 1 hour. Two hours after raising the temperature to the target temperature, the isocyanate group content is measured according to a method (polyurethane raw material aromatic isocyanate test method) based on JIS Z1603-1: 2007. And in prepolymer A and C, it confirms that the isocyanate group content rate is in the range of 4.0 to 5.0%. In prepolymer B, it is confirmed that the isocyanate group content is in the range of 2.0 to 3.0%. Moreover, in the prepolymer D, it confirms that the isocyanate group content rate exists in the range of 0.5 to 1.0%. In the prepolymer E, it is confirmed that the isocyanate group content is in the range of 0.3 to 0.8%. Moreover, in the prepolymer F, it confirms that the isocyanate group content rate exists in the range of 6.0-7.0%. In the prepolymer G, it is confirmed that the isocyanate group content is in the range of 0.5 to 1.0%. Moreover, in the prepolymer H, it confirms that the isocyanate group content rate exists in the range of 14.0-15.0%. And when isocyanate group content rate is not in the range according to each prepolymer, reaction time is extended.

  After confirming that the isocyanate group content is within the range corresponding to each prepolymer, at least one of vinyl ether, acrylate and allyl ether is slowly dropped in the amount shown in the figure, and the reaction is carried out for 2 hours. . After 2 hours, the isocyanate group content is measured again according to the above method, and it is confirmed that the isocyanate group content is 0.5% or less. And each "prepolymer" shown to a figure is obtained on condition that the isocyanate group content rate is 0.5% or less.

  The theoretical molecular weight of “Prepolymer A” obtained as described above is 4129, the theoretical molecular weight of “Prepolymer B” is 3992, the theoretical molecular weight of “Prepolymer C” is 4101, “ The theoretical molecular weight of “Prepolymer D” is 12609, the theoretical molecular weight of “Prepolymer E” is 24783, the theoretical molecular weight of “Prepolymer F” is 1609, and the theoretical molecular weight of “Prepolymer G” is 36783. The theoretical molecular weight of “Prepolymer H” is 909.

Polyol a: Polypropylene glycol (PPG), trade name: Actol D2000 (Mw: 2000), manufactured by Mitsui Chemicals, Inc. Polyol b: Polypropylene glycol (PPG), trade name: Actol D1000 (Mw: 1000), Polyol c manufactured by Mitsui Chemicals, Inc .; Polypropylene glycol (PPG), trade name: Sannix PP-200 (Mw: 200), manufactured by Sanyo Chemical Co., Ltd. • Polyol d; Polypropylene glycol (PPG), trade name: Preminol S4013 (Mw: 12000), manufactured by Asahi Glass Co., Ltd., Polyol e; Polypropylene glycol (PPG), trade name: Preminol S4318 (Mw: 18000), manufactured by Asahi Glass Co., Ltd., polyisocyanate; TDI, trade name: Rupranate T- 80 (Mw: 174.2 BASF, vinyl ether; hydroxybutyl vinyl ether (Mw: 116.2), Nippon Carbide Corporation, allyl ether; hydroxyethyl allyl ether (Mw: 102.1), Nippon Emulsifier Co., acrylate; 2- Hydroxyethyl methacrylate (Mw: 130.1), manufactured by Nippon Shokubai Co., Ltd.

  Further, the total number of equivalents of at least one of an allyl ether group, a vinyl ether group and an acrylate group contained in 100 parts by weight of each “prepolymer” obtained as described above is calculated. And the equivalent number of the thiol group contained in the thiol required as a raw material is calculated by multiplying the calculated equivalent number by the enethiol ratio (equivalent ratio) shown in FIGS. In addition, the compounding ratio of the thiol shown in FIG. 3, FIG. 4, FIG. 6 is the number of moles with respect to 100 parts by weight of the prepolymer. For this reason, the equivalent number of thiol groups is set to a ratio corresponding to the mixing ratio of thiols. Specifically, for example, in the case where the number of equivalents of thiol groups is A, in Example 1, the molar ratio is 100 with respect to thiol C, so the number of equivalents of thiol groups of thiol C is A. The In Example 5, since the molar ratio is 50 with respect to thiol A and the molar ratio is 50 with respect to thiol B, the equivalent number of thiol groups of thiol A is A / 2. The number of equivalents of the thiol group of B is A / 2. Then, the number of moles of each thiol is calculated based on the number of equivalents of thiol groups of each thiol and the number of functional groups of each thiol. Each thiol having the calculated number of moles and 100 parts by weight of the prepolymer are weighed, heated to 80 ° C., and then mixed and stirred.

・ Thiol A; functional group number 2, butanediol bisthiopropionate, trade name: BDTP (Mw: 266.4), manufactured by Sakai Chemical Co., Ltd. ・ thiol B; functional group number 3, trimethylolpropane tris, trade name: TMMP (Mw: 398.5), manufactured by SC Organic Chemical Co., Ltd., Thiol C; functional group number 4, pentaerythritol tetrakis, trade name: PMP (Mw: 488.6), manufactured by SC Organic Chemical Co., Ltd., Thiol D Functional group number 6, dipentaerythritol hexakis, trade name: DPMP (Mw: 783.0), manufactured by SC Organic Chemical Co., Ltd., Thiol E; functional group number 1,2-ethylhexyl-3-mercaptopropionate, product Name: EHMP (Mw: 218.35), manufactured by SC Organic Chemical Co., Ltd.

  The average number of functional groups of the thiol group that reacts with each urethane prepolymer is shown in the column “Average number of functional groups” in FIGS. 3, 4, and 6. Further, the ratio of the total number of equivalents of all thiol groups to the total number of equivalents of one of vinyl ether groups, allyl ether groups and acrylate groups of each urethane prepolymer is shown in FIG. 3, FIG. 4 and FIG. It is shown in the column “Ratio”.

And the raw material mixed by the compounding ratio shown in FIG.3, FIG.4, FIG.6, ie, the mixed prepolymer and thiol, is apply | coated by the predetermined | prescribed film thickness on a release film with sufficient permeability | transmittance. . Next, a natural rubber foam (manufactured by Inoac) or an EPDM foam (manufactured by Inoac) as a base is pressure-bonded onto the applied mixed raw material. In addition, the adhesion surface to the raw material of the EPDM foam is subjected to primer treatment. And the ultraviolet-ray is irradiated to the mixed raw material by which the foam was crimped | bonded from the downward direction of a release film. Thereby, the apply | coated mixed raw material hardens | cures and the sealing member of Examples 1-12 and the sealing member of Comparative Examples 4-8 are formed. Incidentally, the irradiation amount of ultraviolet rays when the mixed raw material is cured is set to 600 mJ / cm ² (365 nm integrated light amount).

In addition, as a sealing member of Comparative Example 1, a thin-film hydrogenated styrene-based thermoplastic elastomer is provided on one surface of a natural rubber-based foam (manufactured by INOAC) as a base or an EPDM-based foam (manufactured by INOAC). Adheres with a double-sided tape. Further, as a sealing member of Comparative Example 2, a thin rubber-like isoprene rubber (non-vulcanized rubber) is provided on one surface of a natural rubber foam (made by INOAC) as a base or an EPDM foam (made by INOAC). Adopted with a double-sided tape. Further, as the seal member of Comparative Example 3, a natural rubber-based foam (made by Inoac) without a film or an EPDM-based foam (made by Inoac) is employed. In Comparative Example 9, a sealing member in which a film was formed on an open-cell soft polyurethane foam (manufactured by INOAC, density 28 kg / m ³ , number of cells 55/25 mm) was employed.

<Evaluation of physical properties of sealing member and coating of sealing member>
With respect to the seal members of Examples 1 to 12 and the seal members of Comparative Examples 1 to 8, the waterstop was evaluated using the instrument 10 described above. In this evaluation, when there was no water leakage when 50 KPa air was supplied, it was evaluated as “O”, and the evaluation result is shown in the column of “Water stop evaluation” in FIGS. Shown for each type. Further, if water leakage occurs when air of less than 50 KPa is supplied, the pressure of the air supplied at that time is indicated in the column of “Water stop evaluation” in FIGS. Shown for each.

  Moreover, the compression set (%) was measured only for the film in accordance with a method based on JIS K 7312: 1996. The measurement results are shown in the “compression set (%)” column of FIGS.

  Based on the above results, a raw material using a urethane prepolymer having at least one of an allyl ether group, a vinyl ether group, and an acrylate group as a terminal functional group on the surface of the foam (substrate) and a polythiol having a thiol group. It can be seen that the water-stopping property of the seal member can be increased by forming a film by the enethiol reaction.

  Specifically, as shown in FIGS. 3 and 4, in the sealing members of Examples 1 to 12, the surface of the foam (substrate) is formed by an enethiol reaction with the raw material using the urethane prepolymer and the polythiol. A film is formed. And in the sealing member of Examples 1-12, all the water-stop evaluation is set as "(circle)", In the film | membrane of the sealing member of Examples 1-12, all compression set is 15% or less. Has been. On the other hand, in the sealing members of Comparative Examples 1 and 2, hydrogenated styrene-based thermoplastic elastomer or isoprene rubber is adhered to the surface of the foam (substrate) as a film with a double-sided tape. Moreover, in the sealing member of the comparative example 3, only the foam (base | substrate) in which the membrane | film | coat is not formed is used. And in the sealing member of Comparative Examples 1-3, the water-stop evaluation is not favorable, and water leakage occurs only by supplying air to 5 KPa. Further, in the coating film of the sealing member of Comparative Example 1, the compression set is very high at 86%, and a large amount of strain remains after the coating film is compressed. Furthermore, in the film of the sealing member of Comparative Example 2, the compression set cannot be measured, and the film is not restored by heating and compressing. From this, it is possible to increase the water-stopping property of the seal member by forming a film on the surface of the foam (substrate) by the enethiol reaction with the raw material using the urethane prepolymer and the polythiol. I understand.

  Furthermore, in the sealing members of Examples 1 to 12, a film can be formed simply by irradiating the mixed raw material obtained by mixing the urethane prepolymer and polythiol with ultraviolet rays. On the other hand, in the sealing members of Comparative Examples 1 and 2, it is necessary to attach a film to the foam (substrate) with a double-sided tape, and the manufacturing process becomes complicated. In addition, in the sealing members of Examples 1 to 12, since the raw material is cured in a state in which the liquid raw material and the surface of the foam (base) are appropriately blended at the time of manufacture, the adhesion between the base and the film is improved. improves. On the other hand, in the sealing members of Comparative Examples 1 and 2, since the foam (base) and the film are stuck by the double-sided tape, the foam (base) and the film are likely to be displaced from time to time. In this way, even when considering the adhesion between the foam (base) and the film, a seal member is used in which a film is formed on the surface of the foam (base) with raw materials using urethane prepolymer and polythiol. It is preferable to do.

  The ratio of the total number of equivalents of all thiol groups to the total number of equivalents of at least one vinyl ether group, allyl ether group and acrylate group of each urethane prepolymer (ene / thiol ratio) is too high or too low. However, the evaluation of water stoppage becomes worse. Specifically, in all the sealing members of Examples 1 to 12, the ene / thiol ratio is 0.7 to 2.5, and the water-stopping evaluation is good. On the other hand, in the sealing member of Comparative Example 5, the ene / thiol ratio is 0.5, and the evaluation of the waterstop performance is not good. Moreover, in the sealing member of Comparative Example 6, the ene / thiol ratio is 3, and the evaluation of water-stopping is not good. Therefore, the ene / thiol ratio is preferably 0.7 to 2.5.

  Moreover, when the average functional group number of the polythiol mix | blended as a raw material of a film | membrane is too low, the performance as a sealing member will fall. Specifically, in all the sealing members of Examples 1 to 12, the average number of functional groups of polythiol is 2 or more, the water-stopping evaluation is good, and the compression set is 15% or less. On the other hand, in the sealing member of Comparative Example 4, the average functional group number of polythiol is 1.8, the evaluation of water-stopping is not good, and the film is not restored when measuring the compression set, so the compression set is measured. I can't. From this, it is preferable that the average functional group number of polythiol is 2 or more.

  Moreover, the performance as a sealing member will fall if the weight average molecular weight of the urethane prepolymer mix | blended as a raw material of a film | membrane is too high or too low. Specifically, in all the sealing members of Examples 1 to 12, the weight average molecular weight of the urethane prepolymer is 1609 to 24783, the evaluation of waterstop is good, and the compression set is also 15% or less. Yes. On the other hand, in the seal member of Comparative Example 7, the weight average molecular weight of the urethane prepolymer is 36783, and in the seal member of Comparative Example 8, the weight average molecular weight of the urethane prepolymer is 909. And in the sealing member of the comparative example 7 and the comparative example 8, evaluation of a water stop is not favorable. Moreover, in the sealing member of Comparative Example 7, the compression set is 25%. Moreover, in Comparative Example 9, the water-stopping evaluation was not good, and water leakage could be confirmed from the foam part having a small amount of compression. Therefore, the weight average molecular weight of the urethane prepolymer is preferably 1000 to 30000 in consideration of errors.

Claims (6)

A base made of elastically deformable closed cells;
Using a composition comprising a urethane prepolymer having at least one of an allyl ether group, a vinyl ether group, and an acrylate group as a terminal functional group, and a polythiol having a thiol group, it is formed on at least a part of the surface of the substrate. A sealing member provided with a coating.   The sealing member according to claim 1, wherein the average number of functional groups of the polythiol is 2 or more.   The ratio of the total number of equivalents of thiol groups of the polythiol to the total number of equivalents of allyl ether groups, vinyl ether groups and acrylate groups of the urethane prepolymer is 0.7 to 2.5. The sealing member according to claim 1 or 2.   The weight average molecular weight of the said urethane prepolymer is 1000-30000, The sealing member as described in any one of Claim 1 thru | or 3 characterized by the above-mentioned.   The seal member according to any one of claims 1 to 4, wherein a compression set (JIS K 7312: 1996) of the film is 20% or less. A raw material comprising a urethane prepolymer having at least one of an allyl ether group, a vinyl ether group and an acrylate group as a terminal functional group and a polythiol having a thiol group is attached to at least a part of the surface of the elastically deformable substrate. An adhesion process;
An irradiation step of irradiating the raw material adhered in the adhesion step with light, and producing a seal member by a photopolymerization reaction.

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