JP5498262B2 - Moisture curable sealing composition and sealing composition sheet - Google Patents

Description

  The present invention relates to a moisture curable sealing composition used for filling gap portions and the like, and a sealing composition sheet obtained by molding the moisture curable sealing composition into a sheet.

  Conventionally, as a sealing composition used for filling a gap portion or the like, a sealing composition such as a heat curable type, a moisture curable type, or an ultraviolet curable type is known depending on the object to be sealed.

  Among these, the moisture curable sealing composition is normally in a liquid state at room temperature, and is widely used for filling gaps that cannot be heated or irradiated with ultraviolet rays. As such a moisture curable sealing composition, for example, a moisture curable silicone resin composition containing a silicone resin, a silane coupling agent and a modified silicone resin has been proposed.

JP 2007-262140 A

  However, since the silicone resin composition described in Patent Document 1 described above is prepared as a liquid, the amount of the silicone resin composition injected into the gap portion is likely to vary due to its fluidity, and uniform filling is possible. Have difficulty.

  In addition, in the silicone resin-based composition, a low boiling point component is generated at the time of curing, so that the working environment is lowered.

  On the other hand, a putty-like sealing composition made of rubber whose viscosity has been adjusted has also been proposed in order to improve the above problems.

  However, in such a putty-like sealing composition, the viscosity is likely to change depending on the environmental temperature, the viscosity becomes excessively high at a low temperature, the followability to the gap portion is lowered when the gap portion is filled, and the viscosity is excessive at a high temperature. However, after filling the gap portion, sagging and flow are generated, resulting in a void.

  Accordingly, an object of the present invention is to form a moisture-curing sealing composition capable of improving the followability to the gap portion and uniformly filling the gap portion, and the moisture-curing sealing composition in sheet form. It is to provide a sealing composition sheet.

  In order to achieve the above object, the moisture curable sealing composition of the present invention is characterized by containing a carboxyl group-containing polymer having a carboxyl group, a plasticizer, and a metal carbonate.

  In the moisture curable sealing composition of the present invention, the hardness before curing was measured 10 seconds after the pressure surface of the type C durometer was brought into close contact in the type C hardness test defined in JIS K 7312. Sometimes it is 5 to 50.

  Moreover, in the moisture hardening type sealing composition of this invention, it is suitable that 0.1-10 mass% of carboxyl groups are contained in the said carboxyl group containing polymer.

  In the moisture-curable sealing composition of the present invention, the carboxyl group-containing polymer is 55 to 95% by mass of an acrylic acid alkyl ester monomer, 4 to 40% by mass of a cyano group-containing vinyl monomer, and a carboxyl group. It is preferable to be obtained by polymerizing a monomer composition containing 0.1 to 10% by mass of the vinyl monomer.

  Moreover, in the moisture hardening type sealing composition of this invention, it is suitable to contain a tackifier further.

  Moreover, in the moisture hardening type sealing composition of this invention, it is suitable that the said plasticizer contains 10-300 mass parts with respect to 100 mass parts of said carboxyl group containing polymers.

  In the moisture curable sealing composition of the present invention, the metal carbonate is preferably contained in an amount of 5 to 200 parts by mass with respect to 100 parts by mass of the carboxyl group-containing polymer.

  In the moisture curable sealing composition of the present invention, it is preferable that the metal carbonate is calcium carbonate.

  In addition, the sealing composition sheet of the present invention is characterized in that the above moisture-curing sealing composition is formed into a sheet shape.

  According to the moisture curable sealing composition of the present invention, the followability to the gap portion can be improved and the gap portion can be filled uniformly.

  The moisture curable sealing composition of the present invention contains a carboxyl group-containing polymer having a carboxyl group, a plasticizer, and a metal carbonate.

  Examples of the carboxyl group-containing polymer include polymers obtained by carboxyl-modifying isoprene rubber, butadiene rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, styrene-butadiene-styrene block polymer, styrene-isoprene-styrene block polymer, acrylic polymer ( Rubber or resin), preferably carboxyl-modified acrylic polymer.

  The carboxyl-modified acrylic polymer is a monomer containing a (meth) acrylic acid alkyl ester monomer ((meth) acryl means acryl or methacryl; the same shall apply hereinafter) and a carboxyl group-containing vinyl monomer. It is obtained by polymerizing the monomer composition.

  Examples of the (meth) acrylic acid alkyl ester include, for example, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, (meth) Sec-butyl acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate , Octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) Isodecyl acrylate, undecyl (meth) acrylate, (meth) acrylic acid Such as Lil, and (meth) acrylic acid alkyl ester having a linear or branched alkyl group having 2 to 12 carbon atoms. Preferably, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, (meth) Examples include (meth) acrylic acid alkyl esters having a linear or branched alkyl group having 2 to 4 carbon atoms such as t-butyl acrylate.

  By using such a (meth) acrylic acid alkyl ester monomer, it is possible to ensure flexibility before curing of the moisture curable sealing composition and improve followability with respect to the gap portion. The shape retention of the sheet can be improved.

  Examples of the carboxyl group-containing vinyl monomer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, crotonic acid, and cinnamic acid, such as fumaric anhydride, maleic anhydride, Examples thereof include unsaturated dicarboxylic acid anhydrides such as itaconic anhydride.

  In addition, the monomer composition may contain a monomer copolymerizable with the above-described monomer. Examples of such a monomer include a reactive functional group-containing vinyl monomer. And polyfunctional vinyl monomers. Preferably, a reactive functional group-containing vinyl monomer is used.

  Examples of the reactive functional group-containing vinyl monomer include cyano group-containing vinyl monomers such as (meth) acrylonitrile, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, and the like. Hydroxyl group-containing vinyl monomers, for example, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, epoxy group-containing vinyl monomers such as glycerin di (meth) acrylate, for example, aminoethyl (meth) acrylate, (meth) Amino group-containing vinyl monomers such as dimethylaminoethyl acrylate, for example, isocyanate group-containing vinyl monomers such as 2-methacryloyloxyethyl isocyanate, for example, amide group-containing vinyl monomers such as (meth) acrylamide, N- cyclohexyl maleimide, maleimide-based imide group-containing vinyl monomers such as N- isopropyl maleimide. Preferably, a cyano group-containing vinyl monomer is used.

  Examples of the polyfunctional vinyl monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and tetraethylene glycol di (meta). ) Acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, tetramethylolmethane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. (Mono or poly) alkylene polyol poly (meth) acrylate and the like.

  The monomer composition comprises 90 to 99.9% by mass, preferably 92 to 99.5% by mass of an acrylic acid alkyl ester monomer, and a carboxyl group-containing vinyl monomer and 0.1 to 55% by mass. %, Preferably 0.5 to 8% by mass. When the monomer composition contains a copolymerizable monomer, it is contained in a proportion of less than 55% by mass.

  When the monomer composition contains a cyano group-containing vinyl monomer as a copolymerizable monomer, the monomer composition contains 55 to 95% by mass of an acrylic acid alkyl ester monomer. , Preferably 60 to 90% by weight, carboxyl group-containing vinyl monomer 0.1 to 10% by weight, preferably 0.5 to 8% by weight, cyano group-containing vinyl monomer 4 to 40% by weight Preferably, it contains 8-35 mass%.

  The polymerization method of the acrylic polymer may be a known method, and can be appropriately selected from, for example, suspension polymerization, bulk polymerization, and emulsion polymerization.

  In the polymerization of acrylic polymer, known polymerization initiators, reaction solvents, chain transfer agents, emulsifiers and the like can be used as appropriate. In the polymerization of acrylic polymer, when a reaction solvent is used, the reaction solvent is distilled off by a method such as distillation after the reaction.

  These carboxyl group-containing polymers contain, for example, 0.1 to 10% by mass, preferably 0.5 to 8% by mass of carboxyl groups.

  If the carboxyl group content is less than 0.1% by mass, the moisture-absorbing curable sealing composition may not be sufficiently cured. If the carboxyl group content exceeds 10% by mass, the carboxyl group-containing polymer may become excessively hard at room temperature (25 ° C.).

  The plasticizer is not particularly limited as long as the carboxyl group-containing polymer can be plasticized, and examples thereof include a phthalic acid plasticizer and a fatty acid plasticizer.

  Examples of the phthalic acid plasticizer include dioctyl phthalate (DOP), dioctyl tin laurate (DOTL), dibutyl phthalate (DBP), dilauryl phthalate (DLP), butyl benzyl phthalate (BBP), diisodecyl phthalate (DIDP), diisononyl. Examples thereof include phthalic acid esters such as phthalate (DINP), dimethyl phthalate, and diethyl phthalate.

  Examples of the fatty acid plasticizer include adipate esters such as dioctyl adipate (DOA), diisononyl adipate (DINA), diisodecyl adipate, propylene glycol adipate polyester, butylene glycol adipate polyester, and the like.

  Examples of the plasticizer include higher alcohols (for example, lauryl alcohol, stearyl alcohol), drying oils and animal and vegetable oils (for example, paraffins (paraffinic oil), waxes, naphthenes, aromas, Asphalts, linseed oil, etc.), petroleum oils, low molecular weight polymers, organic acid esters (eg, phosphate esters, higher fatty acid esters, alkyl sulfonate esters, etc.).

  These plasticizers can be used alone or in combination of two or more. Moreover, as a plasticizer, Preferably, a fatty acid type plasticizer is mentioned, More preferably, an adipic acid ester is mentioned.

  A plasticizer is mix | blended with the compounding ratio of 10-300 mass parts with respect to 100 mass parts of carboxyl group-containing polymers, for example, Preferably it is 15-200 mass parts.

  When the blending ratio of the plasticizer is less than 10 parts by mass with respect to 100 parts by mass of the carboxyl group-containing polymer, the flexibility of the moisture-curing sealing composition before curing becomes insufficient, and the moisture-curing sealing composition It may be difficult to follow the shape of the gap portion. Moreover, when the compounding ratio of the plasticizer exceeds 300 parts by mass with respect to 100 parts by mass of the carboxyl group-containing polymer, it may be difficult to cure the hygroscopic curable sealing composition.

  Examples of metal carbonates include carbonates of Group 2 elements (Group 2 elements in the periodic table (IUPAC inorganic chemical nomenclature revised edition (1989))) such as calcium carbonate, magnesium carbonate, strontium carbonate, and barium carbonate, For example, carbonates of Group 12 elements such as zinc carbonate (Group 12 elements in the Periodic Table (IUPAC Inorganic Chemical Nomenclature Revision (1989))), for example, manganese carbonate, ferrous carbonate, ferrous carbonate Examples thereof include carbonates of transition metals such as cobalt, nickel carbonate, and cupric carbonate. Preferably, a carbonate of a Group 2 element, more preferably, calcium carbonate is used.

  If the metal carbonate is a carbonate of a Group 2 element, metal ions can be easily generated, and a cross-link is formed by an ionic bond between the metal ion of the metal carbonate and the carboxyl group of the carboxyl group-containing polymer. can do.

  The metal carbonate is appropriately blended according to the type of the carboxyl group-containing polymer and the content of the carboxyl group. Specifically, for example, 3 to 200 parts by mass with respect to 100 parts by mass of the carboxyl group-containing polymer, Preferably, it mix | blends by the compounding ratio of 10-180 mass parts.

  When the blending ratio of the metal carbonate is less than 3 parts by mass with respect to 100 parts by mass of the carboxyl group-containing polymer, it may be difficult to cure the moisture-curable sealing composition. Moreover, when the compounding ratio of the metal carbonate exceeds 200 parts by mass with respect to 100 parts by mass of the carboxyl group-containing polymer, the curing rate of the moisture curable sealing composition becomes excessively high, and the moisture curable sealing composition When the pot life is shortened or the moisture-curing sealing composition before curing is insufficiently flexible, it may be difficult to make the moisture-curing sealing composition follow the shape of the gap.

  Moreover, a tackifier can also be mix | blended with the moisture hardening type sealing composition of this invention as needed.

  Examples of the tackifier include rosin resins, rosin esters, terpene resins (for example, terpene-aromatic liquid resins, polyterpene resins, etc.), coumarone resins, indene resins, coumarone indene resins, petroleum resins ( For example, C5 / C9 petroleum resin and the like, phenol resin and the like. Preferably, coumarone resin is used.

  The tackifier is blended at a blending ratio of, for example, 200 parts by weight or less, preferably 10 to 150 parts by weight with respect to 100 parts by weight of the carboxyl group-containing polymer.

  If the tackifier is mix | blended with the moisture hardening type sealing composition, the adhesiveness of the moisture hardening type sealing composition with respect to a seal | sticker object can be improved.

  Moreover, well-known additives, such as a filler, a pigment, anti-aging agent, a flame retardant, can be suitably mix | blended with the moisture hardening type sealing composition of this invention as needed.

  Examples of the filler include hollow fillers such as hollow beads, foamable fillers such as heated foam beads, and inorganic fillers other than the above-described metal carbonates such as talc. Preferably, a hollow filler and a foamable filler are used.

  If the filler is a hollow filler or a foamable filler, the apparent density of the moisture curable sealing composition can be reduced, and the moisture curable sealing composition can be reduced in weight.

  In order to prepare the moisture curable sealing composition of the present invention, a carboxyl group-containing polymer, a plasticizer, a metal carbonate, and, if necessary, a tackifier and an additive are blended in the above blending ratio, for example, a mixing roll or the like. For example, at 50 to 150 ° C.

  In addition, when preparing a moisture hardening type sealing composition, it mixes in dry gas, for example so that it may not contact with moisture for a long time.

  Thereby, a moisture hardening type sealing composition is prepared in the viscous paste shape (putty shape).

  The gel fraction (toluene insoluble content) of the obtained moisture curable sealing composition is, for example, 10% by mass or less, preferably 5% by mass or less.

  Moreover, the tensile strength (according to JIS K 6767) at an elongation rate of 100% of the obtained moisture curable sealing composition is, for example, 30 N or less, preferably 20 N or less.

  Further, the obtained moisture curable sealing composition has a hardness before curing measured 10 seconds after the pressure surface of the type C durometer is brought into close contact in a type C hardness test specified in JIS K 7312. For example, 5 to 50, preferably 5 to 30.

  The hardness before curing of the moisture curable sealing composition can be prepared by adjusting the blending amount of the plasticizer and the blending amount of the metal carbonate, and when the above-described hardness is less than 5, The moisture curable sealing composition may flow out of the gap before curing due to sagging or flow, and if it exceeds 50, the moisture curable sealing composition becomes insufficient in flexibility and the moisture curable sealing composition. It may be difficult to follow the shape of the gap portion.

  The moisture curable sealing composition is filled in the gaps and the like, and then cured by absorbing the surrounding moisture.

  Specifically, when the moisture-curable sealing composition absorbs ambient moisture, an ionic bond is formed between the metal ion of the metal carbonate and the carboxyl group of the carboxyl group-containing polymer.

  The gel fraction (toluene insoluble content) of the moisture-curing sealing composition after curing is, for example, 30% by mass or more, and preferably 40% by mass or more.

  The tensile strength (according to JIS K 6767) of the moisture curable sealing composition after curing at 100% elongation is, for example, 1N or more, preferably 5N or more, and usually 30N or less.

  The moisture curable sealing composition may be directly filled in the gap using a spatula or the like, or may be formed in advance into a sheet to form a sealing composition sheet, and the gap may be filled with the sealing composition sheet. it can.

  In order to form the sealing composition sheet, for example, the moisture-curable sealing composition is rolled into a sheet having a predetermined thickness by using a known press machine, extrusion molding machine, or the like. Moreover, a moisture-curable sealing composition can be applied to both surfaces of a substrate such as a nonwoven fabric to form a sealing composition sheet.

  The moisture curable sealing composition and the sealing composition sheet are sealed until used so as not to come into contact with water or moisture.

  According to this moisture curable sealing composition, it is possible to ensure flexibility and improve followability with respect to the gap portion before curing, regardless of viscosity adjustment. It is possible to prevent the flow and suppress the generation of voids in the gap portion, and to uniformly fill the gap portion.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1
A monomer composition comprising 85 parts by mass of butyl acrylate, 2 parts by mass of acrylic acid, and 15 parts by mass of acrylonitrile was polymerized to produce a carboxyl-modified acrylic polymer A (carboxyl group-containing polymer, carboxyl group content 1.2 masses). %, Solid content 100%).

  Acrylic polymer A, adipic acid ester (Polysizer P-103, manufactured by DIC) and calcium carbonate are blended in the blending ratios shown in Table 1, and mixed at 120 ° C. using a mixing roll to obtain a moisture-curable sealing composition. Obtained.

  The obtained moisture-curing sealing composition was rolled with a press to obtain a sealing composition sheet having a thickness of 1 mm.

Examples 2-5
Except for blending acrylic polymer A, adipic acid ester (Polysizer P-103, manufactured by DIC), calcium carbonate, and coumarone resin (tackifier, Coumarone V-120, manufactured by Nikko Chemical) at the blending ratio shown in Table 1. In the same manner as in Example 1, a moisture-curing sealing composition and a sealing composition sheet were obtained.

Example 6
A monomer composition consisting of 85 parts by mass of butyl acrylate, 6 parts by mass of acrylic acid and 15 parts by mass of acrylonitrile was polymerized by suspension polymerization, and carboxyl-modified acrylic polymer B (carboxyl group-containing polymer, carboxyl group content 3 0.5% by mass, solid content 100%).

  Moisture curable sealing composition and sealing composition in the same manner as in Example 1 except that acrylic polymer B, adipic acid ester (Polysizer P-103, manufactured by DIC) and calcium carbonate were blended in the blending ratio shown in Table 1. A product sheet was obtained.

Comparative Example 1
Putty-like sealing composition in the same manner as in Example 1, except that acrylic polymer A, adipic acid ester (Polysizer P-103, manufactured by DIC), and talc (filler) were blended in the blending amounts shown in Table 1. And a sealing composition sheet was obtained.

Comparative Example 2
A commercially available one-part curable silicone resin (liquid, acetone type) was used.

Evaluation method 1. Measurement of gel fraction (toluene insoluble content) Using the moisture curable sealing composition obtained in each Example and each Comparative Example, before curing and after curing (cured at a temperature of 40 ° C. and a humidity of 90% for 12 hours) Thereafter, the toluene-insoluble content of the same in the following test was measured.

The moisture curable sealing composition before or after curing was weighed and immersed in toluene for 48 hours to swell and dissolve. Thereafter, this was filtered through a 300-mesh wire mesh, and the toluene insoluble matter captured by the wire mesh was dried and weighed. And the percentage of the dry mass of a toluene insoluble content with respect to the mass of the moisture hardening type sealing composition before hardening or after hardening was computed. The results are shown in Table 1.
2. Hardness test Using the moisture-curing sealing composition (before curing) obtained in each example and each comparative example, a type C hardness test was performed according to JIS K 7312, and a pressure surface of a type C durometer The hardness after 10 seconds from the contact was measured. The results are shown in Table 1.
3. Tensile strength test Measured according to JIS K 6767. Specifically, the sealing composition sheet before or after curing in each example and each comparative example was punched out using dumbbell No. 1 to obtain a measurement sample. Using a tensile tester, the measurement sample was pulled at a pulling speed of 500 mm / min, and the load (100% tensile strength) when the elongation percentage of the measurement sample reached 100% was measured. The results are shown in Table 1.
4). Odor test A sensory test based on the sense of smell of the tester was performed on the odor when the moisture-curable sealing compositions of the examples and the comparative examples were cured. The results are shown in Table 1.

Claims (9)

A carboxyl group-containing polymer having a carboxyl group;
A plasticizer,
Containing metal carbonates ,
The carboxyl group-containing polymer is obtained by polymerizing a monomer composition containing a (meth) acrylic acid alkyl ester monomer, a cyano group-containing vinyl monomer, and a carboxyl group-containing vinyl monomer. A moisture-curing sealing composition, wherein   The hardness before curing is 5 to 50 when measured 10 seconds after the pressure surface of the type C durometer is brought into close contact in the type C hardness test specified in JIS K 7312. The moisture-curable sealing composition according to claim 1.   The moisture curable sealing composition according to claim 1 or 2, wherein a carboxyl group is contained in the carboxyl group-containing polymer in an amount of 0.1 to 10% by mass. The monomer composition is
(Meth) acrylic acid alkyl ester monomer 55-95% by mass;
4 to 40% by mass of a cyano group-containing vinyl monomer;
Characterized in that it contains a carboxyl group-containing vinyl monomer 0.1 to 10 mass%, the moisture-curing sealing composition according to any one of claims 1 to 3. The moisture-curable sealing composition according to any one of claims 1 to 4, further comprising a tackifier. The moisture-curable sealing composition according to any one of claims 1 to 5, wherein the plasticizer is contained in an amount of 10 to 300 parts by mass with respect to 100 parts by mass of the carboxyl group-containing polymer. object. The moisture curable sealing according to any one of claims 1 to 6, wherein the metal carbonate is contained in an amount of 5 to 200 parts by mass with respect to 100 parts by mass of the carboxyl group-containing polymer. Composition. The moisture-curable sealing composition according to any one of claims 1 to 7, wherein the metal carbonate is calcium carbonate. A moisture-curable sealing composition according to any one of claims 1 to 8, wherein the moisture-curable sealing composition is formed into a sheet shape.