Primer composition for glass adhesive

Abstract

The invention relates to a primer composition for glass adhesive, comprising: a first silane polymer containing an epoxy group and an amino group; a second silane polymer containing a mercapto group; an epoxy resin; an acrylic polymer; and a pigment, wherein the epoxy equivalent of the epoxy resin is 100 g / eq to 500 g / eq.

Description

Technical Field

[0001] The present invention relates to a primer composition for a glass adhesive having excellent storage stability and excellent glass adhesion. Background Art

[0002] When bonding glass to a painted surface of a vehicle body, in order to prevent the glass from being detached or falling off from the painted surface due to insufficient adhesion between the painted surface and the glass, which are different materials, generally, a primer is first applied to the painted surface and / or the glass surface, and then a wet hardening adhesive (e.g., DGU) is applied to the primer to bond the glass to the painted surface. In this case, the wet hardening adhesive contains a polyurethane resin, which is a reactant of an isocyanate and a polyol, as a resin component, and contains carbon black, calcium carbonate, etc. as a pigment component, and also contains a plasticizer such as diisononyl phthalate (DINP). In addition, the primer may contain: a film former such as an epoxy resin, a silane polymer, or an acrylic resin; and additives such as a pigment such as carbon black and an inorganic filler (e.g., titanium oxide, calcium carbide, and silicic anhydride, etc.).

[0003] However, additives such as pigments or inorganic fillers added to improve the adhesion and physical properties of the primer may cause the precipitation of additive particles in the composition during storage, resulting in reduced storage stability. In order to solve such problems, a dispersant is usually added to the primer.

[0004] As an alternative, Korean published patent application No. 2017-0016433 (Patent Document 1) discloses a primer composition containing an acrylic copolymer, a titanium compound and a solvent. However, the composition of Patent Document 1 has poor adhesion due to lack of wettability with the ceramic coating surface of the automotive glass, and has problems of poor water resistance and chemical resistance due to monosilane and titanium compounds.

[0005] Therefore, there is a need to research and develop a primer composition for a glass adhesive having excellent storage stability and excellent adhesion (cohesion) between glass and the adhesive. Summary of the invention

[0006] [Technical issues]

[0007] Therefore, the present invention is to provide a primer composition for a glass adhesive having excellent storage stability and excellent adhesion to glass.

[0008] [Technical solution]

[0009] The invention provides a primer composition for glass adhesive, comprising: a first silane polymer containing epoxy groups and amino groups, a second silane polymer containing mercapto groups, epoxy resin, acrylic polymer and pigment, wherein the epoxy equivalent of the epoxy resin is 100 g / eq to 500 g / eq.

[0010] [Beneficial Effects]

[0011] The primer composition for glass adhesive according to the present invention includes a low equivalent weight epoxy resin and has excellent storage stability by preventing the precipitation of pigments in the composition during long-term storage, and includes two silane polymers with different functional groups, thereby having excellent adhesion due to a rapid coupling reaction (condensation reaction) with glass, and therefore, the primer composition is suitable for use as a primer. DETAILED DESCRIPTION

[0012] Hereinafter, the present invention will be described in detail.

[0013] In the present invention, the "weight average molecular weight" and "number average molecular weight" of the resin may be measured by a method well known in the art, and for example, it may represent a value measured by a gel permeation chromatography (GPC) method.

[0014] Furthermore, in the present specification, the term "(meth)acrylic acid" means "acrylic acid" and / or "methacrylic acid", and the term "acrylate" means "acrylate" and / or "methacrylate".

[0015] In the present specification, the unit "parts by weight" refers to the weight ratio between the components.

[0016] A primer composition for glass adhesive according to the present invention comprises a first silane polymer, a second silane polymer, an epoxy resin, an acrylic polymer and a pigment. In particular, the primer comprises two types of silane polymers with different reactive groups, so that it can have excellent adhesion due to reaction with materials formed on the glass surface or chemical bonding (coupling reaction) with the glass.

[0017] In addition, since the primer composition forms a structure in which the oil-based or water-based adhesive applied to one surface of the primer and the primer coating are chemically bonded to each other as a network in a subsequent process, it exhibits excellent adhesion and solvent resistance, and can serve as a primer having very excellent adhesion and cohesion to an organic coating (substrate) formed by curing the adhesive and a glass surface (i.e., an inorganic material surface).

[0018] On the other hand, since a urethane bond is formed between the hydroxyl group of the epoxy resin included in the primer composition of the present invention and the excess isocyanate group of the subsequently applied moisture-hardening urethane adhesive, the adhesion between the layers can be greatly improved.

[0019] In addition, two different silane polymers are hydrolyzed by the solvent to form silanol, which then forms a urethane bond with the excess isocyanate of the subsequently coated wet-hardening urethane adhesive, and at the same time forms a siloxane bond with the silicon compound in the portion in contact with the glass surface, thereby improving the adhesion between the glass surface-primer-urethane adhesive layer.

[0020] First silane polymer

[0021] The first silane polymer is used to impart adhesion and compatibility to the adhesive (substrate) and glass, which are the surfaces to which the prepared coating is attached.

[0022] The first silane polymer contains an epoxy group and an amino group, and can be prepared from epoxy silane and amino silane. Specifically, the first silane polymer can be prepared by reacting epoxy silane and amino silane at 40° C. to 60° C. for 20 to 50 hours.

[0023] In this case, the epoxy silane may be, for example, a glycidyloxy C 1-5 Alkyl C 1-5 Alkoxysilane, specifically, can be a glycidyloxy C 1-5 Alkyl tri-C 1-5 Alkoxysilane. Specifically, the epoxy silane may be, but is not limited to, glycidyloxymethyl trimethoxysilane, glycidyloxyethyl trimethoxysilane, glycidyloxypropyl trimethoxysilane, glycidyloxymethyl triethoxysilane, glycidyloxyethyl triethoxysilane, glycidyloxypropyl triethoxysilane, glycidyloxymethyl tripropoxysilane, glycidyloxyethyl tripropoxysilane, glycidyloxypropyl tripropoxysilane, and the like.

[0024] In addition, the aminosilane may be, for example, a silane containing one or more amino groups. For example, the aminosilane may be an aliphatic silane containing two or more amino groups. Specifically, the aminosilane may be an amino C 1-5 Alkyl-tri-C 1-5 Alkoxysilane, for example, may be, but is not limited to, aminomethyl-trimethoxy-silane, aminoethyl-trimethoxy-silane, aminopropyl-trimethoxy-silane, aminoethyl-aminopropyl-trimethoxy-silane, and the like.

[0025] A first solvent may be used in the reaction of epoxy-based silane and amino-based silane, and the first solvent may be methyl ethyl ketone, ethyl acetate, dimethyl carbonate, methanol, n-butanol, or the like.

[0026] Epoxy silane and amino silane may be reacted in a weight ratio of 1:0.1 to 1.1, or 1:0.4 to 1.0. If the reaction weight ratio of epoxy silane to amino silane is less than the above range, i.e., a smaller amount of amino silane is used compared to epoxy silane, the adhesion to the adhesive (substrate) may be reduced due to insufficient attachment functional groups. If the reaction weight ratio exceeds the above range, i.e., an excess of amino silane is used compared to epoxy silane, the excess unreacted amino groups in the composition may deteriorate the weather resistance and water resistance of the coating, and the storage performance during storage may also deteriorate.

[0027] In addition, the first silane polymer may have an epoxy equivalent weight (EEW) of 1,300 to 15,000 g / eq, or 3,000 to 13,000 g / eq, and a weight average molecular weight (Mw) of 500 to 3,000 g / mol, or 1,000 to 3,000 g / mol.

[0028] If the epoxy equivalent and weight average molecular weight of the first silane polymer are within the above ranges, the storage performance and adhesion are excellent. If the epoxy equivalent of the first silane polymer is less than the above range, the dispersibility of the pigment and / or additive particles may be reduced due to the low epoxy equivalent, which may lead to the problem of poor storage performance. If the epoxy equivalent of the first silane polymer is high, the first silane polymer reacts with the isocyanate group of the adhesive to be applied later to form fine pores, so the problem of poor adhesion may occur. In addition, if the weight average molecular weight of the first silane polymer is less than the above range, the problem of poor storage properties may occur, and if the weight average molecular weight of the first silane polymer exceeds the above range, the problem of poor adhesion may occur.

[0029] The weight average molecular weight (Mw) of the first silane polymer may be smaller than the weight average molecular weight (Mw) of the second silane polymer to be described later. As described above, if two types of silane polymers having different functional groups and different weight average molecular weights are used, the reactivity with the glass surface is improved due to the different condensation reactivity of the two types of silane polymers with the glass surface, thereby improving adhesion and storage stability.

[0030] On the other hand, if the weight average molecular weight (Mw) of the first silane polymer is greater than the weight average molecular weight (Mw) of the second silane polymer, the condensation reaction is reduced, the adhesion to the glass surface is reduced, and peeling may occur.

[0031] The weight average molecular weight (Mw) of the first silane polymer may be 10 g / mol to 14500 g / mol or 1000 g / mol to 10000 g / mol less than the weight average molecular weight of the second silane polymer. If the difference between the weight average molecular weights of the first silane polymer and the second silane polymer is negligible, such as less than the above range, there are excessive unreacted amino groups, and therefore, the storage properties of the composition may be reduced. If the difference exceeds the above range, the storage properties of the composition may be reduced due to side reactions.

[0032] The first silane polymer may be included in the composition in an amount of 20 to 50 parts by weight, or 30 to 40 parts by weight relative to 0.5 to 3.5 parts by weight of the second silane polymer. If the content of the first silane polymer is within the above range, it has the effect of improving the long-term storage of the primer and the adhesion to the glass. If the content of the first silane polymer is lower than the above range, the problem of decreased storage performance may occur, and if the amount of the first silane polymer included exceeds the above range, the problem of poor adhesion due to the lack of an attachment functional group to the adhesive may occur.

[0033] In addition, the first silane polymer and the second silane polymer described later can be included in the composition at a weight ratio of 10 to 60: 1. Specifically, the first silane polymer and the second silane polymer can be included in the composition at a weight ratio of 10 to 50: 1, or 12 to 46: 1. That is, the composition of the present invention can include a first silane polymer with a relatively small weight average molecular weight more than the second silane polymer with a relatively large weight average molecular weight. If the weight ratio of the first silane polymer and the second silane polymer is included in the above range, there are many silanol functional groups, so there is an excellent effect of adhesion to glass. If the weight ratio of the first silane polymer and the second silane polymer is less than the above range, that is, based on the second silane polymer including a small amount of the first silane polymer, there is a problem of insufficient storage stability due to side reactions. If the weight ratio exceeds the above range, that is, based on the second silane polymer including an excessive amount of the first silane polymer, the problem of insufficient adhesion to glass may occur.

[0034] Second Silane Polymer

[0035] The second silane polymer contains a mercapto group, which imparts adhesion to the substrate and glass (which are the attachment surfaces of the prepared coating film), improves the weather resistance of the prepared coating film, and improves the storage stability of the composition by preventing the precipitation of the pigment.

[0036] The second silane polymer can be prepared from, for example, mercapto-based silane, amino-based silane, acrylate compounds, and isocyanate compounds. If the composition includes the second silane polymer prepared from the above compounds, it has an effect of having excellent adhesion to glass due to different reactivity due to including different types of silane polymers.

[0037] The mercapto silane imparts adhesion to the substrate and glass as the attachment surface. The mercapto silane may be, for example, mercapto C 1-5 Alkyl C 1-5 Alkoxysilane, specifically, may be mercapto C 1-5 Alkyl tri-C 1-5 Alkoxysilane. Specifically, the mercapto silane may be, but is not limited to, mercaptomethyltrimethoxysilane, mercaptoethyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptomethyltriethoxysilane, mercaptoethyltriethoxysilane, mercaptopropyltriethoxysilane, mercaptomethyltripropoxysilane, mercaptoethyltripropoxysilane, mercaptopropyltripropoxysilane, and the like.

[0038] The aminosilane imparts adhesion to the substrate and glass as the attachment surface. The aminosilane may be, for example, a silane containing one or more amino groups, and specifically, may be a silane containing one amino group. For example, the aminosilane may be C 6-10 Arylamino C 1-5 Alkyl-tri-C 1-5 The alkoxysilane may be, for example, but is not limited to, phenylaminomethyltrimethoxysilane, phenylaminoethyltrimethoxysilane, phenylaminopropyltrimethoxysilane, phenylaminomethyltriethoxysilane, phenylaminoethyltriethoxysilane, phenylaminopropyltriethoxysilane, and the like.

[0039] The acrylate compound imparts weather resistance to the prepared coating film. For example, the acrylate compound may be an aryloxyalkyl acrylate or a C 6-12 Aryloxy-C 1-6 Alkyl acrylate: Specifically, the acrylate compound may contain 2-hydroxy-3-phenoxypropyl acrylate.

[0040] The isocyanate compound imparts adhesion to the silane polymer. In addition, the isocyanate compound may be a compound containing one or more isocyanate groups, for example, a compound containing two or more or three or more isocyanate groups. Specifically, the unreacted isocyanate content (NCO%) of the isocyanate compound may be 5% to 20% by weight, or 8% to 15% by weight, based on the total weight of the compound, but is not limited thereto.

[0041] When preparing the second silane polymer, additives such as a second solvent, a catalyst and a reaction stabilizer may be used. The second solvent may be, but is not limited to, methyl ethyl ketone, ethyl acetate, dimethyl carbonate, n-butanol, and the like.

[0042] The second silane polymer may be prepared by reacting the amino-based silane, the mercapto-based silane, the acrylate-based compound, and the isocyanate compound in a weight ratio of 1:2.5-6.0:2.5-6.0:8-20, or 1:3.5-5.5:3.5-5.5:9-18.

[0043] If the content of mercaptosilane is less than the above range, that is, a small amount of mercaptosilane is included based on the aminosilane, there is a problem of poor adhesion to glass. If the content exceeds the above range, that is, an excessive amount of mercaptosilane is included based on the aminosilane, unreacted mercaptosilane may remain, and thus there may be a problem of decreased storage properties.

[0044] In addition, if the content of the acrylate compound is lower than the above range, that is, a small amount of acrylate compound is included based on the amino silane, there is a problem of poor working adhesion. If the content exceeds the above range, that is, an excessive amount of acrylate compound is included based on the silane compound, there may be a problem of poor storage properties.

[0045] In addition, if the content of the isocyanate compound is lower than the above range, i.e., a small amount of the isocyanate compound is included based on the aminosilane, the reaction may not be sufficiently performed, and the degree of crosslinking may be reduced, and thus, a problem of pigment precipitation may occur. If the content exceeds the above range, i.e., an excessive amount of the isocyanate compound is included based on the aminosilane, a problem of deterioration of storage properties may occur.

[0046] The weight average molecular weight (Mw) of the second silane polymer can be 3000 g / mol to 15000 g / mol, or 5000 g / mol to 10000 g / mol, and the number average molecular weight (Mn) can be 1000 g / mol to 7000 g / mol, or 3000 g / mol to 5000 g / mol. If the weight average molecular weight and number average molecular weight of the second silane polymer are within the above range, there is an excellent effect of storage and adhesion to glass. On the other hand, if the weight average molecular weight and number average molecular weight of the second silane polymer are less than the above range, there is a problem of poor adhesion to glass, and if they exceed the above range, the problem of poor storage may occur.

[0047] The second silane polymer may be included in the composition in an amount of 0.5 to 3.5 parts by weight, 0.6 to 3.1 parts by weight, or 0.7 to 2.9 parts by weight based on 20 to 50 parts by weight of the first silane polymer. If the content of the second silane polymer is within the above range, both storage properties and adhesion are excellent. In addition, if the content of the second silane polymer is lower than the above range, insufficient adhesion to glass occurs, and if the content of the second silane polymer exceeds the above range, insufficient storage stability at room temperature causes pigment precipitation.

[0048] Epoxy resin

[0049] The epoxy resin can impart adhesion to the glass and substrate and impart film-forming properties to the primer composition.

[0050] The epoxy resin is a low equivalent weight epoxy resin having an epoxy equivalent of 100 to 500 g / eq. If the low equivalent weight epoxy resin is included in the composition, the coating film forming property and storage stability are excellent, thus preventing the pigment from precipitating, thereby improving the storage stability and product reliability of the composition.

[0051] In addition, the epoxy resin may be a bisphenol epoxy resin, particularly a bisphenol glycidyl ether. Specifically, the epoxy resin may be bisphenol A glycidyl ether. If bisphenol A glycidyl ether is used as the epoxy resin, it has an excellent adhesive effect on the substrate.

[0052] Generally, the urethane adhesive applied to one side of the primer coating film is mixed and applied in the presence of an excess of an isocyanate component. Some of the excess isocyanate component reacts with moisture, and the remaining excess isocyanate component reacts with the hydroxyl group of the epoxy resin, thus forming a urethane bond and exhibiting the effect of enhancing the interlayer adhesion between the primer and the adhesive.

[0053] Specifically, epoxy resin is liquid type, and epoxy resin with the epoxy equivalent of 100g / eq to 500g / eq, 100g / eq to 400g / eq or 120g / eq to 300g / eq can be used to appropriately control storage property and adhesion. If the epoxy equivalent of epoxy resin is within the above range, the pigment particles in the primer composition will not separate out in a short time, so there is an excellent effect of storage property and storage stability. On the other hand, if the epoxy equivalent of epoxy resin is less than the above range, the functional group that can react with the adhesive to form a bond is reduced, resulting in poor drying and poor adhesion to substrate. In addition, if the epoxy equivalent of epoxy resin exceeds the above range, the dispersibility in the composition is reduced, so that when the composition is stored at room temperature, the problem of pigment separation may occur.

[0054] In addition, the viscosity of the epoxy resin at 25° C. may be 10,000 cps to 15,000 cps, or 11,000 cps to 14,000 cps. If the viscosity of the epoxy resin is within the above range, it has an effect of excellent storage properties. If the viscosity of the epoxy resin is less than the above range, the adhesion to the substrate is poor, and if the viscosity of the epoxy resin exceeds the above range, a cross-linking reaction occurs during storage, and the storage properties may be deteriorated.

[0055] The weight average molecular weight (Mw) of epoxy resin can be 1000g / mol or less, or 300g / mol to 450g / mol. If the weight average molecular weight of epoxy resin is within the above range, storage property can be excellent. In addition, if the weight average molecular weight of epoxy resin is less than the above range, the adhesion to substrate is poor, and if the weight average molecular weight of epoxy resin exceeds the above range, the problem of storage property degradation may occur.

[0056] In addition, the specific gravity of the epoxy resin at 20° C. may be 0.8 to 1.5, or 1.0 to 1.3. If the specific gravity of the epoxy resin at 20° C. is within the above range, it has an effect of excellent storage properties. In addition, if the specific gravity of the epoxy resin is less than the above range, the adhesion to the substrate may be poor, and if the specific gravity of the epoxy resin exceeds the above range, the problem of poor storage properties may occur.

[0057] For 20 to 50 parts by weight of the first silane polymer, the epoxy resin can be included in the composition in an amount of 2 to 5 parts by weight, or 1.4 to 4.8 parts by weight. If the content of the epoxy resin is within the above range, the effect of excellent storage and adhesion is achieved. In addition, if the content of the epoxy resin is lower than the above range, when the composition is stored at room temperature, due to insufficient storage stability, there may be a problem of pigment precipitation. If the content of the epoxy resin exceeds the above range, the problem of foaming or fading of the primer layer may occur due to the thermal decomposition of the epoxy resin, thereby the problem of insufficient weather resistance of the prepared coating film may occur.

[0058] Acrylic polymer

[0059] The acrylic polymer can impart tack and adhesion to the primer composition.

[0060] The acrylic polymer can be directly synthesized according to a known method, or a commercially available product can be used. In this case, the acrylic polymer can be prepared from, for example, an alkyl-containing (meth) acrylate monomer, an epoxy-containing (meth) acrylate monomer, and a hydroxyl group and an aromatic ring-containing (meth) acrylate monomer.

[0061] The (meth)acrylate monomer containing an alkyl group improves the adhesiveness and adhesion of the acrylic polymer. In addition, the (meth)acrylate monomer containing an epoxy group reacts with the amino group or the imino group of the silane polymer to form an adhesion site (-OH) with the adhesive to improve the adhesion of the composition. In addition, the (meth)acrylate monomer containing a hydroxyl group and an aromatic ring forms an attachment site (-OH) with the adhesive to improve the adhesion of the composition and the weather resistance of the primer.

[0062] For example, acrylic acid polymers can be made from 1-3 Alkyl group (meth) acrylate monomer, containing C 4-10 (Meth)acrylate monomers containing alkyl groups, (meth)acrylate monomers containing glycidyl groups, and (meth)acrylate monomers containing hydroxyl groups and C 6-12 Specifically, the acrylic polymer may include C-containing (meth)acrylates in a weight ratio of 1:0.1 to 5:0.01 to 1:0.01 to 1, or 1:0.5 to 2:0.2 to 0.6:0.2 to 0.6. 1-3 Alkyl group (meth) acrylate monomer, containing C 4-10 (Meth)acrylate monomers containing alkyl groups, (meth)acrylate monomers containing glycidyl groups, and (meth)acrylate monomers containing hydroxyl groups and C 6-12 Aromatic ring (meth)acrylate If the weight ratio of each monomer satisfies the above range, the formability, tackiness and adhesion of the film can be improved.

[0063] If it contains C 4-10 The content of the (meth)acrylate monomer containing an alkyl group is lower than the above range, that is, relative to the C 1-3 For (meth)acrylate monomers containing alkyl groups, a small amount of C 4-10 If the (meth)acrylate monomer contains C 4-10 The content of the (meth)acrylate monomer containing an alkyl group exceeds the above range, that is, relative to the C 1-3 For (meth)acrylate monomers containing alkyl groups, 4-10 If the content of the (meth)acrylate monomer having an alkyl group is too high, the storage stability may be reduced.

[0064] In addition, if the content of the (meth)acrylate monomer containing epoxy groups is lower than the above range, that is, relative to the C-containing 1-3 If the content exceeds the above range, i.e., relative to the C-containing (meth)acrylate monomer, the moldability of the coating film may be deteriorated if a small amount of the epoxy group-containing (meth)acrylate monomer is included. 1-3For the (meth)acrylate monomer containing an alkyl group, if the content of the (meth)acrylate monomer containing an epoxy group is too high, the storage property may be poor.

[0065] If the hydroxyl group and C 6-12 The content of (meth)acrylate containing aromatic ring is lower than the above range, that is, relative to the content of (meth)acrylate containing C 1-3 For (meth)acrylate monomers containing alkyl groups, a small amount of hydroxyl groups and C 6-12 If the content exceeds the above range, that is, relative to the content of C-containing (meth)acrylate, there is a problem of insufficient curing reaction and reduced film formability. 1-3 For (meth)acrylate monomers containing an excess of hydroxyl groups and C 6-12 Aromatic (meth)acrylates may have a problem of poor storage properties.

[0066] The weight average molecular weight (Mw) of acrylic polymer can be 150000g / mol to 250000g / mol, 170000g / mol to 220000g / mol or 180000g / mol to 2000000g / mol. If the weight average molecular weight of acrylic polymer is within the above range, then there is the effect of excellent adhesion and processability. In addition, if the weight average molecular weight of acrylic polymer is less than the above range, then the adhesion to substrate may decline, and if it exceeds the above range, then the storage property may decline.

[0067] In addition, the glass transition temperature (Tg) of the acrylic polymer may be 30° C. to 70° C., 40° C. to 60° C., or 45° C. to 55° C. If the glass transition temperature of the acrylic polymer is within the above range, there is an effect of excellent adhesiveness and processability. In addition, if the glass transition temperature of the acrylic polymer is lower than the above range, the adhesion to the substrate may decrease, and if it exceeds the above range, the storage property may decrease.

[0068] The viscosity of the acrylic polymer at 25° C. may be 200 cps to 1500 cps, 400 cps to 1000 cps, or 600 cps to 850 cps. If the viscosity of the acrylic polymer at 25° C. is within the above range, there is an effect of excellent adhesiveness and processability. In addition, if the viscosity of the acrylic polymer is lower than the above range, the adhesion to the substrate may be reduced, and if it exceeds the above range, the storage property may be reduced.

[0069] In addition, the acrylic polymer may be included in the composition in an amount of 5 to 30 parts by weight or 10 to 20 parts by weight relative to 20 to 50 parts by weight of the first silane polymer. If the content of the acrylic polymer is within the above range, both adhesion and processability are excellent. In addition, if the content of the acrylic polymer is lower than the above range, adhesion to the substrate may decrease, and if it exceeds the above range, storage properties may decrease.

[0070] pigment

[0071] Pigments can impart color to the primer composition and improve physical properties such as weatherability, durability, strength, and the like.

[0072] Any pigment can be used as the above-mentioned pigment without particular limitation, as long as it is generally contained in the coating composition and does not deteriorate the physical properties and functions. For example, extender pigments, white pigments, black pigments, yellow pigments, red pigments, blue pigments, green pigments, metal powder pigments, pearl pigments, metallic pigments, etc. can be used as pigments without limitation.

[0073] Pigments may include, preferably, body pigments such as barium sulfate (Ba2SO4, calcite), barite, calcium carbonate (CaCO3), clay (Al2O3·2SiO2·2H2O, bone meal (3MgO·4SiO2·H2O), silicon dioxide powder (SiO2), diatomaceous earth (SiO2·nH2O), silica, bentonite, talc and aluminum silicate; white pigments such as titanium oxide (TiO2), zinc oxide (ZnO), lithopone, zinc sulfide, white lead (2PbCO3·Pb(OH)2) and antimony oxide (Sb2O3); black pigments such as carbon black, graphite and iron black (Fe3O4); yellow pigments such as titanium oxide (TiO2), zinc oxide (ZnO), lithopone, zinc sulfide, white lead (2PbCO3·Pb(OH)2) and antimony oxide (Sb2O3); black pigments such as carbon black, graphite and iron black (Fe3O4); yellow pigments such as aluminum oxide (TiO2), zinc oxide (ZnO), zinc lithopone, zinc sulfide, white lead (2PbCO3·Pb(OH)2) and antimony oxide (Sb2O3 ... Color pigments, such as chrome yellow (PbCrO3), zinc chromate, cadmium yellow (CdS), lead cyanide (PbCN2), titanium yellow (TiO2-NiO-Sb2O3) and strontium yellow (SrCrO4); red pigments, such as iron oxide red (Fe2O3), lead tetroxide (Pb3O4), mercuric sulfide (HgS), cadmium red (mixed crystal of CdS and HgS), molybdenum red (mixed crystal of PbCrO4, PbMoO4 and PbSO4) and cuprous oxide (Cu2O); blue pigments, such as Prussian blue (MFe[Fe(CN)6], M=K, NH4, Na), ultramarine (2(Al2Na2Si3O 10)·Na2S4) and cobalt blue (CoO·nAl2O3); green pigments such as chrome green (a mixture of PbCrO4 and Prussian blue KFe[Fe(CN)6]), chromium oxide (Cr2O3) and chromium hydroxide (Cr2O3.2H2O); metal powder pigments such as aluminum powder and bronze powder; and pearl pigments such as natural pearl powder and synthetic pearl pigment, and in order to improve the color and weather resistance of the primer composition of the present invention, carbon black can be used.

[0074] The pigment may be included in the composition in an amount of 5 to 10 parts by weight or 6 to 8 parts by weight relative to 20 to 50 parts by weight of the first silane polymer. If the content of the pigment is lower than the above range, the hiding effect and appearance of the cured primer coating may deteriorate. If the content of the pigment exceeds the above range, the dispersibility of the pigment in the primer composition deteriorates, so the pigment takes a long time to disperse, or precipitation occurs during the storage of the prepared primer composition, which may cause problems with the storage stability and product reliability of the primer.

[0075] Solvents

[0076] The primer composition may further include a solvent. In this case, the solvent may control the viscosity and drying properties of the composition.

[0077] The solvent is not particularly limited as long as it can be added to a common primer composition for glass. For example, the solvent may include: aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as hexane, octane and isoparaffin; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone; acetate solvents such as ethyl acetate and isobutyl acetate; ether solvents such as diisopropyl ether and 1,4-dioxane; carbonate solvents such as dimethyl carbonate and diethyl carbonate, and the like.

[0078] In addition, the solvent may be included in the composition in an amount of 30 to 50 parts by weight or 30 to 40 parts by weight relative to 20 to 50 parts by weight of the first silane polymer. If the content of the solvent is lower than the above range, the viscosity of the primer composition will be too high, and therefore the dispersibility of the pigment in the composition and the storage stability of the composition will deteriorate. If the content of the solvent exceeds the above range, the viscosity of the primer composition is too low, so that the flow or film between the cushions may be unevenly formed during the coating process, and problems such as insufficient adhesion to the substrate or adhesive and poor weather resistance of the prepared film may occur.

[0079] additive

[0080] The primer composition may also include one or more additives, such as storage stabilizers, dispersants, and moisture absorbers, to improve the physical properties of the coating.

[0081] The additive may be included in the composition in an amount of 1 to 5 parts by weight or 1.5 to 3.5 parts by weight relative to 20 to 50 parts by weight of the first silane polymer.

[0082] The storage stabilizer can improve workability by extending the application period of the primer composition, and improve storage stability by preventing the precipitation of the pigment in the composition. In addition, the storage stabilizer is not particularly limited as long as it can be added to a common primer composition for glass, and for example, can include diethyl malonate, trimethyl orthoacetate, methanol, ethanol, isopropyl alcohol, trimethyl orthoformate, etc., but is not limited thereto.

[0083] The dispersant can improve the storage stability of the composition by uniformly and stably dispersing the pigment in the composition. In addition, the dispersant is not particularly limited unless it is applied to the glass primer to reduce physical properties, and commercially available products may include EFKA PU 4061, LUBRIZOL 2063, DISPERBYK-180, DISPERBYK-110, DISPERBYK-2152, etc., but are not limited thereto.

[0084] The moisture absorbent can control the moisture content of the primer composition and improve the processability. In addition, the moisture absorbent is not particularly limited as long as it can be applied to a common primer for glass, and examples thereof may include sodium / calcium aluminosilicate, zeolite, aldimine, oxazolidine, trimethoxyvinylsilane, etc., but are not limited thereto.

[0085] As described above, the primer composition for a glass adhesive according to the present invention has excellent storage stability and excellent adhesion to glass, and thus is suitable for fixing glass of an automobile.

[0086] [Implementation model]

[0087] Hereinafter, the present invention will be described in more detail by way of examples. However, these examples are only used to help understand the present invention, and the scope of the present invention is not limited to these examples in any sense.

[0088] Synthesis Example 1. Preparation of the First Silane Polymer-1

[0089] In a reaction container, add 3.57 g of N-(β-aminoethyl)-γ-aminopropyl-trimethoxy-silane, 8.3 parts by weight of γ-glycidyloxypropyltrimethoxysilane, 7.71 g of methyl ethyl ketone, 15.61 g of dimethyl carbonate and 1.14 g of methanol, and react at 60°C for 48 hours to prepare the first silane polymer-1.

[0090] The epoxy equivalent weight (EEW) of the prepared first silane polymer-1 is 3500 g / eq, and the weight average molecular weight (Mw) is 2800 g / mol.

[0091] Synthesis Examples 2 and 3. Preparation of First Silane Polymers-2 and 3

[0092] The preparation method of the first silane polymer is the same as that in Synthesis Example 1, except that the contents of amino silane, N-(β-aminoethyl)-γ-aminopropyl-trimethoxysilane and epoxy silane, γ-glycidyloxypropyltrimethoxysilane in the reaction container are adjusted as shown in Table 1.

[0093] [Table 1]

[0094]

[0095] Synthesis Example 2. Preparation of the Second Silane Polymer-1

[0096] In a reaction container, 0.47 g of ethyl acetate, 0.002 g of tin catalyst (stannous octoate, T-9), 0.16 g of (3-mercaptopropyl)trimethoxysilane, 0.18 g of 2-hydroxy-3-phenoxypropyl acrylate (HPPA), 0.04 g of N-phenyl-3-aminopropyltrimethoxysilane, 0.65 g of isocyanate compound (manufacturer: Bayer, product name: Desmodur HL) and 0.0001 g of hydroquinone as a reaction stabilizer were added, and reacted at 60°C for 5 hours to prepare the second silane polymer-1.

[0097] The prepared second silane polymer-1 had an unreacted NCO group content (NCO%) of 0.0 wt % or less, a weight average molecular weight (Mw) of 7600 g / mol, a number average molecular weight (Mn) of 3600 g / mol, and a polydispersity index (PDI) of 2.11.

[0098] Synthesis Examples 5 to 11. Preparation of Second Silane Polymers 2 to 8

[0099] The preparation method of the second silane polymer is the same as that of Synthesis Example 4, except that the content of the monomer in the reaction container is adjusted as shown in Table 2.

[0100] [Table 2]

[0101]

[0102]

[0103] Synthesis Example 12. Preparation of acrylic acid polymer

[0104] In a reaction container, 9.49 g of methyl ethyl ketone, 1.62 g of methyl methacrylate (MMA), 1.62 g of butyl methacrylate (BMA), 0.71 g of glycidyl methacrylate (GMA), 0.79 g of 2-hydroxy-3-phenoxypropyl acrylate (HPPA) and 0.07 g of tert-butyl peroxide were added and reacted at 80° C. for 12 hours to prepare an acrylic polymer.

[0105] The prepared acrylic polymer had a weight average molecular weight (Mw) of 200,000 g / mol, a glass transition temperature (Tg) of 48.1° C., and a viscosity at 25° C. of 800 cps.

[0106] Experimental Example 1. Preparation of primer composition

[0107] In a reaction container, 36.33 g of the first silane polymer-1 of Synthesis Example 1, 1.50 g of the second silane polymer-1 of Synthesis Example 4, 14.3 g of the acrylic polymer of Synthesis Example 12, 7 g of carbon black as a pigment, 3 g of epoxy resin-1, 0.36 g of a desiccant, 1.4 g of a dispersant, 0.60 g of a storage stabilizer, 20.8 g of ethyl acetate and 14.7 g of dimethyl carbonate were added, and stirred at 600 rpm for 20 minutes using a high-speed stirrer to prepare a primer composition.

[0108] Experimental Examples 2 to 16.

[0109] A primer composition was prepared in the same manner as in Experimental Example 1, except that the content of each component described in Table 3 and Table 4 was used.

[0110] [Table 3]

[0111]

[0112]

[0113] [Table 4]

[0114]

[0115]

[0116] Table 5 below shows the manufacturer and product name of each component used in the Experimental Examples.

[0117]

[0118] Test example: Evaluation of physical properties

[0119] The physical properties of the primer composition of the experimental example were measured in the following manner, and the results are shown in Table 6 below.

[0120] (1) Waterproof

[0121] The composition of the experimental example was coated on a glass surface with a coating area of ​​25 mm (width) x 150 mm (length) x 3 mm (height), and placed at 20°C and 65% relative humidity for 72 hours, and then the sample was exposed to a Xeon WEATHER-O-METER (WOM) for 1000 hours. After exposure, the sample was taken out and placed at 20°C for 1 hour. Then, the primer layer at one end of the sample was cut with a 15 mm knife, and the substrate of the coating was held with one hand and peeled off with a knife at an angle of 30°. Thereafter, the adhesion was evaluated by calculating the percentage of the adhesive area that was not adhered to the primer (the interface between the primer layer and the adhesive peeled off) to the total area of ​​the adhesive layer after curing. In this case, the adhesion was evaluated as better due to the increase in the adhesion area.

[0122] Here, the XENON test conditions were performed according to MS600-35.

[0123] (2) Shear strength

[0124] The composition was coated on glass and cured at 20° C. and 65% relative humidity for 7 days, a 5 mm thick dog-bone shaped specimen was prepared, and then the shear strength was measured using a universal testing machine (UTM).

[0125] (3) Adhesion

[0126] The composition was applied to a glass of 120 mm (length) x 10 mm (width) x 5 mm (thickness), and a test piece was prepared by compressing a urethane sealant (manufacturer: KCC, product name: PU9510 (S-P2P)) and an adhesive (manufacturer: KCC, product name: PU9370-BTX) thereon. Thereafter, the test piece was cured at 20° C. and 65% relative humidity for 7 days.

[0127] Thereafter, the primer layer at one end of the test piece was cut with a 15 mm knife, and the coated substrate was held with one hand and peeled off with the knife at an angle of 30°. After curing, the adhesion was evaluated by calculating the percentage of the adhesive area that was not adhered to the primer (the peeled interface between the primer layer and the adhesive) to the total area of ​​the adhesive layer after curing. In this case, the adhesion was evaluated to be better because the adhesion area was larger.

[0128] (4) Working Adhesion

[0129] The composition was applied on a glass of 120 mm (length) x 10 mm (width) x 5 mm (thickness) and left at 20°C and 65% relative humidity for 3 months. Then, a test piece was prepared by compressing a urethane sealant (manufacturer: KCC, product name: PU9510 (S-P2P)) and an adhesive (manufacturer: KCC, product name: PU9370-BTX) thereon.

[0130] The test piece was stored at 20°C and 65% relative humidity. When 7 days had passed from the date of coating of the adhesive, an adhesion test was conducted to observe the state of the adhesive interface. Here, the adhesion test was conducted in the same manner as in item (3).

[0131] (5) Storage

[0132] The storage stability was evaluated by visually observing the precipitation of carbon black in the primer composition.

[0133] Specifically, after the composition was left at 20°C for 1 week, if the coating film of the supernatant was black, it was evaluated as good. After the composition was left at 20°C for 1 week, if the coating film of the supernatant was close to black, it was evaluated as poor. After the composition was left at 20°C for 1 week, if the coating film of the supernatant was gray, it was evaluated as weak. After the composition was left at 20°C for 1 week, if the coating film of the supernatant was not black, it was evaluated as defective.

[0134] [Table 6]

[0135]

[0136]

[0137] As shown in Table 6, compared with Experimental Examples 4 to 16, the compositions of Experimental Examples 1 to 3 were excellent in adhesion, working adhesion, and storage stability, and the specimens prepared therefrom were excellent in weather resistance and shear strength.

[0138] Specifically, Experimental Examples 1 to 7 containing an appropriate amount of the second silane polymer exhibited excellent adhesion compared to Experimental Example 8 containing a small amount of the second silane polymer.

[0139] In addition, compared with Experimental Example 9 containing an excessive amount of the second silane polymer, Experimental Examples 1 to 7 containing an appropriate amount of the second silane polymer have excellent storage stability and do not cause precipitation of pigments and carbon black.

[0140] Furthermore, compared with Experimental Example 10 containing the second silane polymer-6 and using a small amount of an acrylate compound compared to the amino-based silane, Experimental Examples 1 to 7 were superior in shear strength and working adhesion.

[0141] In addition, Experimental Examples 1 to 7 had excellent adhesion of 95% or more compared to Experimental Example 11 using the second silane polymer-7 using a small amount of mercapto-based silane compared to amino-based silane.

[0142] Furthermore, compared with Experimental Example 12 using the second silane polymer-8 having a small amount of isocyanate compound compared to amino-based silane, Experimental Examples 1 to 7 have excellent storage stability and do not cause precipitation of pigment carbon black.

[0143] Compared with Experimental Example 13 containing an excessive amount of epoxy resin, Experimental Examples 1 to 7 do not cause foaming or fading of the primer layer due to thermal decomposition of the epoxy resin, and thus have excellent weather resistance and excellent adhesion to glass.

[0144] Furthermore, compared with Experimental Examples 14 and 16 containing Epoxy Resin-2 having a high epoxy equivalent and Experimental Example 15 containing a small amount of epoxy resin, Experimental Examples 1 to 7 had excellent storage stability and no precipitation of pigments and carbon black.

Claims

1. A primer composition for a glass adhesive, comprising: A first silane polymer containing epoxy groups and amino groups, a second silane polymer containing mercapto groups, an epoxy resin, an acrylic polymer and a pigment, Wherein, the epoxy equivalent weight (EEW) of the epoxy resin is 100 g / eq to 500 g / eq, wherein the second silane polymer is prepared by reacting an amino silane, a mercapto silane, an acrylate compound and an isocyanate compound in a weight ratio of 1:2.5 to 6.0:2.5 to 6.0:8 to 20, and The primer composition comprises 20 to 50 parts by weight of a first silane polymer, 0.5 to 3.5 parts by weight of a second silane polymer, 2 to 5 parts by weight of an epoxy resin, 5 to 30 parts by weight of an acrylic polymer and 5 to 10 parts by weight of a pigment.

2. The primer composition according to claim 1, wherein the weight average molecular weight of the first silane polymer is smaller than the weight average molecular weight of the second silane polymer, The weight ratio of the first silane polymer to the second silane polymer is 10 to 60:

1. 3 . The primer composition according to claim 1 , wherein the epoxy resin has a viscosity of 10,000 cps to 15,000 cps at 25° C. and a weight average molecular weight of 1,000 g / mol or less.

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