Solventless adhesive set

Abstract

To provide a solventless adhesive set which does not cause peeling of a sheet even when used in a water section, has high initial tackiness, does not cause lateral displacement of the laminated sheet, and is hardly affected by an environmental temperature.SOLUTION: The present invention provides a solventless-type adhesive set comprising a main agent containing an epoxy resin and a curing agent for curing the epoxy resin, wherein at least one of the main agent and the curing agent contains a fibrous mineral.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a solvent-free adhesive set, and more particularly to a solvent-free adhesive set used for bonding flooring sheets in wet areas such as food factories, hospital operating rooms, restaurant kitchens, toilets, and changing rooms. [Background technology]

[0002] For on-site installation of flooring sheets, both in new construction and renovation work, solvent-based adhesives containing organic solvents are commonly used due to their long history of use and their excellent workability when laminating flooring sheets (good initial tackiness). However, solvent-based adhesives undergo volatile curing, where the organic solvent on the adhesive surface evaporates, causing the adhesive to harden from the surface to the interior. While solvent-based adhesives have excellent initial tackiness, residual organic solvents can cause bubbles. When used in wet areas, water penetration can soften the adhesive, reducing its adhesive strength and causing problems with sheet peeling when the sheet expands and contracts. Furthermore, solvent-based adhesives have the potential to have a negative impact on the environment due to the highly volatile organic solvents they contain. Therefore, for example, a solvent-free, one-component, moisture-curing polyurethane adhesive has been proposed that uses a compound that is liquid at room temperature and has a boiling point above 240°C instead of a highly volatile organic solvent (see Patent Document 1). Such solvent-free adhesives do not generate bubbles, preventing water penetration, and do not soften, so the adhesive strength does not decrease, making it less likely for the sheet to peel off even when the sheet expands or contracts. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-255712 Summary of the Invention [Problem to be solved by the invention]

[0004] However, compared to solvent-based adhesives, solvent-free adhesives have lower initial tackiness, which can lead to problems such as lateral slippage of bonded sheets, and because they do not contain organic solvents, they are susceptible to the effects of environmental temperature.

[0005] To provide a solventless adhesive set in which sheets do not peel off even when used in wet areas, initial tackiness is high, laminated sheets do not slip sideways, and the set is not easily affected by environmental temperature. [Means for solving the problem]

[0006] The inventors have discovered that a solvent-free adhesive set having a specific configuration prevents the sheets from peeling off even when used in wet areas, has high initial tackiness, prevents lateral shifting of the bonded sheets, and is less susceptible to the effects of environmental temperature.

[0007] That is, the present invention provides: A solventless adhesive set including a base agent containing an epoxy resin and a curing agent that cures the epoxy resin, There is provided a solventless adhesive set, in which at least one of the base agent and the curing agent contains a fibrous mineral. The solventless adhesive set may further contain a reaction adjuster that adjusts the curing reaction of the epoxy resin. The aspect ratio (L:D) of the fibrous mineral may be 2:1 to 30:1. The reaction modifier may be an aliphatic amine. The solvent-free adhesive set can be used in construction around wet areas. The solvent-free adhesive set can be used to bond flooring materials. In the solventless adhesive set, at least one of the base agent and the curing agent may further contain an extender pigment. In the solventless adhesive set, at least one of the base agent and the curing agent may further contain a black pigment. The present invention also provides a base agent used in the solventless adhesive set. The present invention also provides a curing agent for use in the solventless adhesive set. The present invention also provides a reaction adjuster for use in the solventless adhesive set. The present invention provides A solventless adhesive comprising a base agent containing an epoxy resin and a curing agent that cures the epoxy resin, There is also provided a solvent-free adhesive, wherein at least one of the base agent and the curing agent contains a fibrous mineral. The solventless adhesive may further contain a reaction adjuster that adjusts the curing reaction of the epoxy resin. The present invention provides A bonding method for bonding objects to be bonded using a solventless adhesive containing a base agent containing an epoxy resin and a curing agent that hardens the epoxy resin, comprising: Also provided is a bonding method, wherein at least one of the base agent and the curing agent includes a fibrous mineral. The solventless adhesive used in the bonding method may further contain a reaction adjuster that adjusts the curing reaction of the epoxy resin. [Effects of the Invention]

[0008] The present invention can provide a solvent-free adhesive set in which the sheets do not peel off even when used in wet areas, the initial tackiness is high, the adhered sheets do not slip sideways, and the set is not easily affected by environmental temperature. The effects of the present invention are not necessarily limited to the effects described herein, and may be any of the effects described in this specification. [Brief explanation of the drawings]

[0009] [Figure 1] This is a schematic diagram showing a top view of a long PVC sheet applied with adhesive to a mortar board and then pasted together. [Figure 2] This is a perspective view of a mortar board M with a long PVC sheet S attached, an iron plate P placed on top of it, and a weight W placed on top. [Figure 3]FIG. 2 is a cross-sectional view of the container showing the thermocouple used in the measurement inside the container and the measurement position of the adhesive when measuring the heat of reaction. [Figure 4] This figure shows the relationship between tan δ, storage modulus (G'), and loss modulus (G") measured with a rheometer (MCR102, manufactured by Anton Paar Japan). [Figure 5] FIG. 1 is a diagram showing the fracture state in a shear tensile test in Example 1, in which the substrate is placed under dry conditions during curing and the substrate is placed under dry conditions after curing. [Figure 6] FIG. 1 is a diagram showing the state of failure in a shear tensile test in Example 1, in which the substrate was placed under dry conditions during curing and the substrate after curing was placed under wet conditions. [Figure 7] FIG. 1 is a diagram showing the state of failure in a shear tensile test in Example 1, in which the substrate is placed under humid conditions during curing and the substrate is placed under humid conditions after curing. [Figure 8] FIG. 10 is a diagram showing the fracture state in a shear tensile test in Comparative Example 1, in which the substrate is placed under dry conditions during curing and the substrate is placed under dry conditions after curing. [Figure 9] FIG. 10 is a diagram showing the state of fracture in a shear tensile test in Comparative Example 1, in which the substrate was placed under dry conditions during curing and the substrate after curing was placed under wet conditions. [Figure 10] FIG. 10 is a diagram showing the state of failure in a shear tensile test in Comparative Example 1, in which the substrate was placed under humid conditions during curing and the substrate was placed under humid conditions after curing. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments for carrying out the present invention will be described below. Note that the embodiments described below are representative embodiments of the present invention, and the scope of the present invention is not limited to these embodiments.

[0011] The present invention will be described in the following order. 1. Description of the Invention 2. First embodiment (example of solvent-free adhesive set) (1) Composition of the solvent-free adhesive set (2) Description of each ingredient 3. Second embodiment (example of solvent-free adhesive) (1) Composition of solvent-free adhesive (2) Manufacturing method of solvent-free adhesive (3) Physical properties (4)Applications 4. Third embodiment (example of bonding method) 5. Working Example

[0012] 1. Description of the Invention

[0013] The inventors discovered that the use of solvent-free adhesives can suppress the generation of bubbles caused by solvents during adhesion and prevent sheet peeling due to moisture intrusion. The inventors also discovered that the inclusion of fibrous minerals in at least one of the epoxy resin-containing base agent and the curing agent that cures the epoxy resin improves tackiness and prevents slippage of the flooring sheet during application. Furthermore, the inventors discovered that by combining a base agent, curing agent, and reaction modifier that regulates the epoxy resin curing reaction and mixing them on-site, it is possible to achieve curing reactivity suited to the ambient temperature.

[0014] 2. First embodiment (example of solvent-free adhesive set)

[0015] (1) Composition of the solvent-free adhesive set

[0016] The solventless adhesive set of this embodiment includes a base agent and a curing agent, and at least one of the base agent and the curing agent contains a fibrous mineral. Furthermore, from the viewpoint of achieving curing reactivity suited to the ambient temperature, the solventless adhesive set of this embodiment may preferably include a reaction modifier that adjusts the curing reaction of the epoxy resin. Furthermore, none of the base agent, curing agent, or reaction modifier contains a volatile organic solvent.

[0017] (2) Description of each ingredient

[0018] [Main ingredient]

[0019] The main agent contained in the solventless adhesive set of this embodiment contains an epoxy resin. The main agent is used in the solventless adhesive set of this embodiment. The epoxy resin will be described below.

[0020] <Epoxy resin>

[0021] The epoxy resin used in this embodiment has an epoxy group in the molecule, and may have two or more epoxy groups in the molecule.

[0022] The epoxy resin is not particularly limited, but may be, for example, one or more selected from the group consisting of dicyclopentadiene-type epoxy resins, novolac-type epoxy resins, triphenylmethane-type epoxy resins, biphenyl-type epoxy resins, naphthalene-type epoxy resins, bisphenol-type epoxy resins, and alicyclic epoxy resins.

[0023] Examples of bisphenol-type epoxy resins include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and bisphenol AD-type epoxy resins. Bisphenol A-type epoxy resins are obtained by reacting bisphenol A with an epoxy group-containing compound such as epichlorohydrin. Bisphenol F-type epoxy resins are obtained by reacting bisphenol F with an epoxy group-containing compound. Bisphenol AD-type epoxy resins are obtained by reacting bisphenol AD ​​with an epoxy group-containing compound. From the viewpoint of a balance of flexibility, chemical resistance, heat resistance, and toughness, bisphenol A-type epoxy resins and bisphenol F-type epoxy resins are preferred.

[0024] The epoxy equivalent (g / eq) of the epoxy resin is not particularly limited, but the preferred lower limit is preferably 50 or more, more preferably 100 or more, and even more preferably 150 or more, and the preferred upper limit is preferably 2000 or less, more preferably 1500 or less, even more preferably 1000 or less, more preferably 500 or less, even more preferably 300 or less, more preferably 250 or less, and even more preferably 200 or less, and the preferred numerical range is more preferably 50 to 1000, and even more preferably 150 to 200.

[0025] The specific gravity (23° C.) of the epoxy resin is not particularly limited, but is preferably 1.00 to 1.20, and more preferably 1.10 to 1.20.

[0026] The viscosity (23° C.) of the epoxy resin is not particularly limited, but is preferably 500 to 30,000 mPa·s, more preferably 1,000 to 20,000 mPa·s, and even more preferably 3,000 to 10,000 mPa·s.

[0027] The content of the epoxy resin in the solventless adhesive obtained by the solventless adhesive set of this embodiment is preferably 10 to 50 mass %, more preferably 20 to 45 mass %, and even more preferably 30 to 40 mass %, of the total mass of the adhesive.

[0028] Commercially available epoxy resins are not particularly limited, but examples thereof include EP-4100 series (manufactured by ADEKA Corporation), BE-188 (Chang Chun Plastics Co., Ltd.), and NPEL-128 (NAN YA Plastic).

[0029] To ensure excellent adhesion to the adhesive object, such as a flooring sheet, and to ensure a long period of time during which the curing reaction is slowed down to maintain workability for application in summer (hereinafter referred to as usable time), the amount of epoxy resin in the base resin of this embodiment is preferably 10 parts by weight or more, more preferably 30 parts by weight or more, even more preferably 50 parts by weight or more, and even more preferably 80 parts by weight or more. The amount of epoxy resin is also preferably 200 parts by weight or less, more preferably 150 parts by weight or less, even more preferably 100 parts by weight or less, and even more preferably 90 parts by weight or less.

[0030] <Fibrous minerals>

[0031] The adhesive produced by the solventless adhesive set of this embodiment is a solventless adhesive that does not contain organic solvents. Because it does not contain organic solvents, thickening is slow and tackiness is insufficient, resulting in the problem of flooring sheets slipping during application. The main agent contained in the solventless adhesive set of this embodiment may contain fibrous minerals to enhance tackiness and prevent flooring sheets from slipping during application. Examples of such fibrous minerals include, but are not limited to, wollastonite. Commercially available wollastonite products include Wollastonite KSP-NO1 (manufactured by Kansai Matec Co., Ltd.), NYAD-G, NYAD400, NYAD1250, and NYGLOS4W (manufactured by Imerys).

[0032] In order to improve tackiness and prevent flooring sheets from slipping when they are installed, in this embodiment, the aspect ratio (L:D) of the fibrous mineral is preferably 2:1 to 30:1, more preferably 4:1 to 20:1, even more preferably 6:1 to 16:1, and even more preferably 9:1 to 14:1.

[0033] To improve tackiness and prevent slippage of the flooring sheet during application, the amount of fibrous mineral in the base agent is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, even more preferably 1 part by weight or more, and even more preferably 2 parts by weight or more. The amount of fibrous mineral is preferably 65 parts by weight or less, more preferably 50 parts by weight or less, even more preferably 35 parts by weight or less, and even more preferably 25 parts by weight or less.

[0034] <Optional ingredients>

[0035] The base resin may contain other components in addition to those listed above, as needed. These other components are not particularly limited, but may include one or more selected from the following: fillers (inorganic and organic), recycled materials, diluents, resin components other than epoxy resins, viscosity modifiers, thixotropy improvers, UV inhibitors, antioxidants, coupling agents, plasticizers, fluxes, flame retardants, colorants, dispersants, emulsifiers, elasticity reducers, defoamers, ion trapping agents, dehydrating agents, organic solvents, metal powders such as zinc powder and aluminum powder, pigments such as color pigments, black pigments, extenders, and rust inhibitors, thickeners, and plasticizers. Among these, one or more selected from inorganic fillers (preferably calcium carbonate powder), resin components other than epoxy resins (preferably coumarone-indene resins), thickeners (fumed silica, etc.), and diluents are more preferred. The "other components" may be commercially available products or those obtained by known manufacturing methods.

[0036] An example of the filler is calcium carbonate powder, which has an average particle size (D50) of preferably 0.01 to 15 μm, more preferably 0.1 to 10 μm, even more preferably 0.1 to 5 μm, and still more preferably 0.1 to 3 μm.

[0037] The base material of this embodiment preferably uses a combination of two or more fillers with different average particle sizes (D50), and more preferably contains a powder composed of a first filler and a second filler with a larger average particle size (D50). The amount of the larger second filler is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 2 parts by mass per part by mass of the first filler. The average particle size (D50) of the first filler is preferably 1.0 μm or more and less than 2.0 μm, and the average particle size (D50) of the second filler is preferably 2.0 μm or more and 3.0 μm or less.

[0038] The content of the viscosity modifier (preferably an inorganic viscosity modifier) ​​is not particularly limited, but is preferably 0.01 to 2 mass %, more preferably 0.1 to 1 mass %, of the total mass of the solventless adhesive. Fumed silica is preferably used as the viscosity modifier. The average particle size (D50) of the viscosity modifier (preferably fumed silica) is preferably 0.1 to 50 nm, more preferably 1 to 20 nm.

[0039] Resin components other than epoxy resins (hereinafter also referred to as "resin components") are not particularly limited, and examples thereof include rosin-based resins (e.g., rosin resins, rosin ester resins, hydrogenated rosin resins, polymerized rosin resins, etc.), terpene-based resins (e.g., α-pinene resins, β-pinene resins, terpene phenol resins, etc.), phenol-based resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aliphatic-aromatic petroleum resins (e.g., styrene-olefin copolymers), aliphatic-alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone resins, and coumarone-indene resins. One or more selected from these may be used. Hydrocarbon resins are preferred as the resin component, and coumarone-indene resins are particularly preferred.

[0040] The resin component is preferably one for modifying resin (for example, for imparting flexibility or impact resistance) or for imparting tack, and more preferably a resin component for modifying resin.

[0041] The weight average molecular weight of the resin component is not particularly limited, but is, for example, preferably about 100 to 500 or about 100 to 300, and more preferably about 120 to 220. The weight average molecular weight of the resin component can be measured by GPC analysis.

[0042] The content of the resin component is preferably 10 to 80 parts by weight, more preferably 20 to 60 parts by weight, and even more preferably 30 to 50 parts by weight, relative to 100 parts by weight of the epoxy resin.

[0043] The content of the resin component (preferably a resin component for hardening modification or adhesion) is preferably 1 to 50 parts by weight, more preferably 10 to 40 parts by mass, per 100 parts by weight of the epoxy resin and other resin components combined.

[0044] The diluent is not particularly limited, but examples thereof include reactive diluents of glycidyl ethers such as glycidyl monoethers, bifunctional glycidyl diethers, and polyfunctional polyglycidyl ethers; and non-reactive diluents such as xylene resins and kerosene, and one or more selected from these can be used. Among these, glycidyl ethers are preferred, and alkyl glycidyl ethers are more preferred.

[0045] The content of the diluent is preferably 1 to 40 parts by mass, more preferably 5 to 30 parts by mass, and even more preferably 10 to 20 parts by mass, relative to 100 parts by mass of the epoxy resin. The epoxy equivalent of the diluent is not particularly limited, but the above-mentioned suitable upper and lower limits of the epoxy equivalent of the epoxy resin can be appropriately adopted, and is preferably 50 to 1,000, more preferably 100 to 400, and even more preferably 130 to 300.

[0046] The content of the diluent in the solvent-free adhesive is preferably 1 to 20 mass %, more preferably 5 to 15 mass %, and even more preferably 8 to 12 mass %, based on the total mass of the solvent-free adhesive.

[0047] [Hardening agent]

[0048] The curing agent contained in the solventless adhesive set of this embodiment cures the epoxy resin. The curing agent is used in the solventless adhesive set of this embodiment. The curing agent will be described below.

[0049] The curing agent for curing the epoxy resin is not particularly limited as long as it can cure the epoxy resin, but examples thereof include compounds having a functional group (or structure) capable of crosslinking with the epoxy resin, such as an amino group (-NH, -NHR, -NR'R), an acid anhydride group, a phenolic hydroxyl group, and polymercaptan. The curing agent is preferably a liquid curing agent from the viewpoints of ease of preparation, ease of blending, and workability. Examples of the curing agent used in this embodiment include amine-based curing agents, acid anhydride-based curing agents, and phenol-based curing agents, among which amine-based curing agents are preferred. One or more types selected from these curing agents or exemplified compounds of these curing agents can be used.

[0050] Examples of amine-based curing agents include polyamine-based compounds (alicyclic polyamines, aromatic polyamines, modified polyamines, etc.), tertiary and secondary amine-based compounds, polyamidoamine-based compounds, and imidazole-based compounds. Polyamine compounds and modified polyamine compounds can be classified into aliphatic and aromatic compounds, and the aliphatic compounds are preferably acyclic (e.g., linear or branched) or cyclic (e.g., alicyclic) non-aromatic compounds. Polyamine compounds include modified aliphatic polyamine compounds (e.g., modified acyclic polyamine compounds, modified alicyclic polyamine compounds). Examples of modified polyamines include amine adducts, polyamine-ethylene oxide or polyamine-propylene oxides, cyanoethylated polyamines, and ketimines. Among the amine-based curing agents, modified aliphatic polyamine-based compounds are preferred, and modified alicyclic polyamine-based compounds are more preferred.

[0051] The amine-based curing agent is not particularly limited, but is preferably one or more selected from, for example, polyethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, bis(aminomethyl)cyclohexane, isophoronediamine, 2,4,6-trisdimethylaminomethylphenol, and the like.

[0052] The modified aliphatic polyamine compound (preferably a modified alicyclic polyamine compound) is not particularly limited, but examples thereof include isophorone diamine, N-aminoethylpiperazine, bis(aminomethyl)cyclohexane, bis(4-amino-3-methyldicyclohexyl)methane, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, norbornene diamine, etc. Among these modified aliphatic polyamine compounds, a combination of at least N-aminoethylpiperazine and bis(aminomethyl)cyclohexane is more preferred.

[0053] The aromatic polyamines are not particularly limited, but examples thereof include diaminodiphenylmethane and m-phenylenediamine.

[0054] The acid anhydride curing agent is not particularly limited, but examples thereof include phthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, and pyromellitic anhydride.

[0055] The phenolic curing agent is generally a monomer, oligomer, or polymer having two or more phenolic hydroxyl groups in one molecule, and is not particularly limited in terms of molecular weight or molecular structure. Examples of the phenolic curing agent include phenol novolac, cresol novolac, phenol aralkyl, naphthol aralkyl, and liquid phenolic resin.

[0056] The content of the curing agent in the solventless adhesive obtained by the solventless adhesive set of this embodiment is preferably 1 to 30 mass %, more preferably 5 to 25 mass %, and even more preferably 10 to 18 mass %, of the total mass of the solventless adhesive.

[0057] The mass content ratio or mass usage ratio of the epoxy resin and the curing agent in the solventless adhesive obtained with the solventless adhesive set of the present embodiment is not particularly limited, but from the viewpoint of better flexibility and better workability, the curing agent is preferably used in an amount of 8 to 250 parts by mass, more preferably 25 to 230 parts by mass, even more preferably 40 to 210 parts by mass, more preferably 70 to 170 parts by mass, and more preferably 85 to 140 parts by mass per 100 parts by mass of the epoxy resin.

[0058] The mass content ratio or mass usage ratio of the main agent to the curing agent in the solventless adhesive obtained by the solventless adhesive set of this embodiment is not particularly limited, but from the viewpoint of better flexibility and better workability, it is preferably 1-20:10-1, more preferably 1-10:5-1, even more preferably 1-5:3-1, and more preferably 1-3:1.

[0059] To slow down the curing reaction and ensure usable time in summer, the amount of the amine curing agent in the curing agent of this embodiment is preferably 15 parts by weight or more, more preferably 20 parts by weight or more, even more preferably 25 parts by weight or more, and even more preferably 30 parts by weight or more. The amount of the amine curing agent is preferably 65 parts by weight or less, more preferably 60 parts by weight or less, even more preferably 55 parts by weight or less, and even more preferably 50 parts by weight or less.

[0060] <Fibrous minerals>

[0061] As with the main agent, the curing agent included in the solventless adhesive set of this embodiment may contain fibrous minerals to prevent slippage of the flooring sheet during application. The same explanation regarding the fibrous minerals in the main agent applies to the fibrous minerals, so the explanation regarding the fibrous minerals will be omitted.

[0062] To improve tackiness and prevent slippage of flooring sheets during application, the amount of fibrous mineral in the hardener is preferably 0.1 parts by weight or more, more preferably 0.6 parts by weight or more, even more preferably 0.8 parts by weight or more, and even more preferably 1 part by weight or more. The amount of fibrous mineral is preferably 65 parts by weight or less, more preferably 50 parts by weight or less, even more preferably 35 parts by weight or less, and even more preferably 25 parts by weight or less.

[0063] <Optional ingredients>

[0064] The curing agent may contain other components in addition to those listed above, as necessary. The optional components used in the base agent may be used as the other components. The explanation of the optional components in the base agent applies to the optional components, so the explanation of the optional components will be omitted.

[0065] [Reaction adjuster]

[0066] The solventless adhesive set of this embodiment preferably contains a reaction adjuster that adjusts the curing reaction of the epoxy resin, from the viewpoint of obtaining curing reactivity that is suited to the ambient temperature. The reaction adjuster will be described below.

[0067] The solventless adhesive obtained using the solventless adhesive set of this embodiment is more susceptible to changes in environmental temperature than solvent-based adhesives containing organic solvents. Specifically, the curing reaction is faster in the summer and slower in the winter. The base agent and curing agent contained in the solventless adhesive set of this embodiment are formulated to slow the curing reaction so that it can be used in the summer. By adding a reaction modifier that adjusts the curing reaction of the epoxy resin to the mixed solution of the base agent and curing agent, it is possible to suppress the delay in the curing reaction at low temperatures in winter and suppress an increase in viscosity.

[0068] The reaction modifier may be any one that can adjust the curing reaction to an appropriate level regardless of the ambient temperature.

[0069] Examples of the reaction adjuster include aliphatic amine-based curing agents, such as PH-760 (manufactured by Chori GLEX Co., Ltd.), which are commercially available.

[0070] To ensure that the curing reaction is appropriate regardless of the ambient temperature, in this embodiment, the amount of the reaction modifier is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, even more preferably 2 parts by weight or more, and even more preferably 3 parts by weight or more. The amount of the reaction modifier is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, even more preferably 20 parts by weight or less, and even more preferably 10 parts by weight or less.

[0071] 3. Second embodiment (example of solvent-free adhesive)

[0072] (1) Composition of solvent-free adhesive

[0073] The solventless adhesive of this embodiment includes a base agent containing an epoxy resin and a curing agent that cures the epoxy resin. At least one of the base agent and the curing agent contains a fibrous mineral. From the viewpoint of obtaining curing reactivity that is compatible with the ambient temperature, the solventless adhesive of this embodiment preferably further includes a reaction adjuster that adjusts the curing reaction of the epoxy resin. Note that the solventless adhesive of this embodiment does not contain a volatile organic solvent.

[0074] The explanations regarding the main agent, hardener, reaction modifier, and fibrous mineral in 2.(2) above apply to the main agent, hardener, and reaction modifier, so explanations regarding the main agent, hardener, reaction modifier, and fibrous mineral will be omitted.

[0075] (2) Manufacturing method of solvent-free adhesive

[0076] The solventless adhesive of this embodiment can be produced by measuring and mixing predetermined amounts of the base agent and curing agent. Specifically, at the construction site where a flooring sheet is attached to mortar or the like, the base agent and curing agent are measured using measuring cups or the like, mixed, and stirred with a mixer such as a hand dispenser, thereby producing the solventless adhesive of this embodiment. Furthermore, if a reaction adjuster is used, the reaction adjuster can be measured and mixed in addition to the base agent and curing agent.

[0077] In consideration of workability at the construction site, the volume ratio of the base agent, curing agent, and reaction modifier (base agent:curing agent:reaction modifier) ​​during mixing is preferably 100:70:15 to 100:170:1, more preferably 100:80:10 to 100:140:2, and even more preferably 100:90:8 to 100:110:3.

[0078] (3) Physical properties

[0079] [Adhesiveness]

[0080] For the solventless adhesive according to this embodiment, a shear tensile test is conducted to evaluate the adhesion between the flooring sheet and the mortar substrate in a wet area. After the test, the adhesion between the flooring sheet and the mortar substrate is visually inspected for failure. If the flooring sheet tears (sheet rupture) or the surface of the flooring sheet is destroyed (sheet surface failure), the adhesion is judged to be good. If the flooring sheet peels from the mortar substrate (separation between the substrate and the adhesive) or the adhesive layer undergoes cohesive failure (failure of the adhesive layer), the adhesion is judged to be poor. The method for evaluating adhesiveness will be described below.

[0081] (Preparation of solvent-free adhesive)

[0082] At room temperature, measure out the required amounts of base resin, curing agent, and reaction modifier using measuring cups, then mix. Stir for 1 minute using a hand mixer.

[0083] (shear tensile test)

[0084] A long PVC sheet is used as the substrate (flooring sheet), and the sheet is cut to 25mm x 12.5mm. A mortar base (25mm x 100mm x 8.0mm) made from Toyoura sand (JIS R5201 compliant) is used as the mortar base. The adhesive to be tested is applied to the mortar base using a notched trowel. The cut sheet is attached to the mortar base with the adhesive applied, and pressed using a handheld roll to create a sample.

[0085] A shear tensile test is carried out on samples placed under the following dry or wet conditions. A universal tensile tester "AG-IS 20kN" (Shimadzu Corporation) is used as the test equipment, and the shear tensile test is carried out at a test speed of 10mm / min, with a bond area of ​​25mm x 12.5mm, a tensile strength of 20kN, and three samples, and the state of failure is confirmed visually.

[0086] <Drying conditions> After leaving the sample at 23°C x 50% rh for 24 hours, the D-mode value of the mortar moisture meter (HI-529-2, manufactured by KETT) is less than 440.

[0087] <Wet conditions> The D-mode value of the mortar moisture meter (HI-529-2, manufactured by KETT) is set to 600 or more, and the sample is cured at 23°C for 7 days. The mortar is kept in a moist state from the day before the test. However, the mortar surface is kept dry.

[0088] [Prevents sheet from slipping before adhesive hardens]

[0089] In order to prevent the sheet from slipping during on-site application, solvent-free adhesives do not contain organic solvents, so thickening is slow and tackiness is lacking. One possible solution to this problem is to speed up the reactivity. However, simply speeding up the reactivity poses the problem of shortening the usable time. The slip prevention ability of the sheet before the adhesive hardens is evaluated based on the usable time measured by a friction test and reaction heat measurement immediately after the sheets are bonded. The friction test and reaction heat measurement are explained below.

[0090] (Friction test)

[0091] At room temperature, measure out and mix the base resin, curing agent, and reaction modifier using measuring cups (mixed amount: 100g). Stir with a hand mixer for 1 minute. Leave to stand for 20 minutes.

[0092] A long PVC sheet was used as the adherend (flooring sheet), and the sheet was cut to 100mm x 120mm. Figure 1 is a schematic diagram showing a top view of a long PVC sheet applied with adhesive to a mortar board and then bonded together. As shown in Figure 1, a notched trowel was used to apply the adhesive to be tested to a mortar board (300mm x 300mm x 50mm). The area where the adhesive was applied is indicated by the shaded area A. The cut sheet was bonded to the adhesive-coated mortar board so that the bonding area was 100mm x 100mm.

[0093] An iron plate is placed on top of the long PVC sheet to distribute the load evenly across the entire surface of the sheet, and a 2 kg weight is placed on top of that to simulate human walking and load. Figure 2 is a perspective view of a mortar board M with a long PVC sheet S attached, an iron plate P placed on top of that, and a weight W placed on top.

[0094] As shown in Figure 1, one end of the wire is hooked onto a clip held at the end of the long PVC sheet, and the other end of the wire is connected to a tensile tester. The tensile tester pulls the wire at a pulling speed of 50 mm / min, gradually shifting the long PVC sheet, and the load (N) applied is measured. If the load is 50 N or more, the slippage prevention property is judged to be good. If the load is less than 50 N, the slippage prevention property is judged to be poor.

[0095] (Reaction heat measurement)

[0096] At room temperature, the base resin, curing agent, and reaction modifier are each measured using measuring cups and mixed (mixed amount: 5 kg). After stirring for 2 minutes with a hand dispenser, measurement of the temperature at the center of the mixed solution begins. Figure 3 shows a cross-sectional view of the container, showing the thermocouple used for measurement within the container and the measurement position of the adhesive when measuring the heat of reaction. As shown in Figure 3, the mixed solution is poured into the container up to 175 mm from the bottom, and the tip of thermocouple D is inserted 80 mm from the inner wall of the container and 87 mm from the bottom. From the start of measurement, the temperature is measured every 10 seconds until it reaches its maximum temperature and begins to decrease. The pot life is the time it takes for the temperature to reach 60°C, a temperature that can be handled by an operator wearing work gloves. A pot life of 30 minutes or more is considered good. A pot life of less than 30 minutes is considered poor.

[0097] [Reactivity at construction sites]

[0098] Solvent-free adhesives are more susceptible to environmental changes (ambient temperature) than solvent-based adhesives. More specifically, the curing reaction is faster in summer due to high temperatures, and slower in winter due to low temperatures. The solvent-free adhesive of this embodiment is formulated to minimize the curing reaction so that it can be used in summer. However, in winter, a reaction modifier is added to prevent the curing reaction from slowing down too much and to suppress an increase in viscosity due to low temperatures.

[0099] To evaluate the reactivity of the solvent-free adhesive of this embodiment at the application site, the time at which tanδ (loss limit: G" / G') reaches its peak is defined as the limit time for sheet adjustment, and the time at which the storage modulus (G': representing solid properties) and loss modulus (G": representing liquid properties) become equal is defined as the adhesive strength development time. Figure 4 shows the relationship between tanδ, storage modulus (G'), and loss modulus (G") measured with a rheometer (MCR102, manufactured by Anton Paar Japan).

[0100] As shown in Figure 4, sheet adjustment is possible at the construction site until the time when the viscosity of the solvent-free adhesive solution reaches its peak (the time when stickiness reaches its peak). When the viscosity of the solution reaches its peak, it is the time when the adhesiveness is at its maximum and the sheet's ability to prevent slippage is at its maximum. The viscosity of this solution is expressed as tan δ, and the time until tan δ reaches its peak is considered the time when sheet adjustment is possible, and is used to evaluate the workability of sheet adjustment. If the time until tan δ reaches its peak is 3 hours or more, it is judged as good. If the time until tan δ reaches its peak is less than 3 hours, it is judged as poor.

[0101] As shown in Figure 4, the time when the storage modulus (G': representing solid properties) and loss modulus (G": representing liquid properties) become the same value is the time when the solution changes from liquid to solid and develops adhesive strength. The time when adhesive strength is developed (adhesive strength development time) is considered good if it is 24 hours or less, and poor if it is more than 24 hours.

[0102] To evaluate the handleability of the solvent-free adhesive according to this embodiment at low temperatures at the construction site, the viscosity of the solvent-free adhesive is measured at room temperature (23°C) and at a low temperature (5°C) using a BH viscometer (TVB10, manufactured by Toki Sangyo Co., Ltd., rotor used: No. 6 rotor) at a rotation speed of 10 rpm. The above-mentioned shear tensile test is also performed at a low temperature (5°C).

[0103] (4)Applications

[0104] The solventless adhesive of this embodiment is used to bond (adhere) concrete or mortar substrates to long PVC sheets as flooring materials in wet areas (wet areas) such as food factories, hospital operating rooms, restaurant kitchens, toilets, and changing rooms. When bonding concrete or mortar substrates to long PVC sheets as flooring materials, it is preferable to use a toothed trowel to ensure a uniform amount of adhesive applied and to ensure air escape routes when the sheets are pressed together. The amount of adhesive applied is preferably 300 to 500 g / m. 2 is.

[0105] 4. Third embodiment (example of bonding method)

[0106] The bonding method of this embodiment is a bonding method for bonding objects using a solventless adhesive containing a base agent containing an epoxy resin and a curing agent that cures the epoxy resin. At least one of the base agent and the curing agent contains a fibrous mineral. From the viewpoint of achieving curing reactivity suited to the ambient temperature, the solventless adhesive used in this bonding method may preferably contain a reaction modifier that adjusts the curing reaction of the epoxy resin.

[0107] The explanations regarding the main agent, hardener, reaction modifier, and fibrous mineral in 2.(2) above apply to the main agent, hardener, and reaction modifier, so explanations regarding the main agent, hardener, reaction modifier, and fibrous mineral will be omitted.

[0108] The present invention can also employ the following configuration. [1] A solventless adhesive set including a base agent containing an epoxy resin and a curing agent that cures the epoxy resin, A solventless adhesive set, wherein at least one of the base agent and the curing agent contains a fibrous mineral. [2] The solventless adhesive set according to [2], further comprising a reaction adjuster that adjusts the curing reaction of the epoxy resin. [3] The solvent-free adhesive set according to [1] or [2], wherein the aspect ratio (L:D) of the fibrous mineral is 2:1 to 30:1. [4] The solventless adhesive set according to [2] or [3], wherein the reaction adjuster is an aliphatic amine. [5] A solvent-free adhesive set according to any one of [1] to [2], which is used in construction around water. [6] The solvent-free adhesive set according to any one of [1] to [5], which is used for adhering flooring materials. [7] The solvent-free adhesive set according to any one of [1] to [6], wherein at least one of the base agent and the curing agent further contains an extender pigment. [8] The solventless adhesive set according to any one of [1] to [7], wherein at least one of the base agent and the curing agent further contains a black pigment. [9] A base agent used in the solventless adhesive set according to any one of [1] to [8].

[10] A curing agent used in the solventless adhesive set according to any one of [1] to [9].

[11] A reaction adjuster used in the solventless adhesive set according to any one of [2] to

[10] .

[12] A solventless adhesive comprising a base agent containing an epoxy resin and a curing agent that cures the epoxy resin, A solvent-free adhesive, wherein at least one of the base agent and the curing agent contains a fibrous mineral.

[13] The solvent-free adhesive according to

[12] , further comprising a reaction adjuster that adjusts the curing reaction of the epoxy resin.

[14] A bonding method for bonding objects to be bonded using a solventless adhesive containing a base agent containing an epoxy resin and a curing agent that hardens the epoxy resin, comprising: The bonding method, wherein at least one of the base agent and the curing agent contains a fibrous mineral.

[15]

[14] The bonding method according to

[14] , wherein the solventless adhesive further contains a reaction adjuster that adjusts the curing reaction of the epoxy resin.

[0109] 5. Working Example

[0110] The present invention will be described in more detail below with reference to examples. Note that the examples described below are representative examples of the present invention, and the scope of the present invention is not limited to these examples.

[0111] In this example, the adhesiveness, the ability to prevent the sheet from slipping before the adhesive hardens, and the reactivity at the construction site were determined by the measurement methods described in the above embodiment.

[0112] [Example 1]

[0113] (Manufacturing of solvent-free adhesives)

[0114] The main component was prepared by mixing at 40°C 75 parts by weight of epoxy resin (trade name "EP-4100" manufactured by ADEKA Corporation), 10 parts by weight of product name "EP-4901" (manufactured by ADEKA Corporation), 15 parts by weight of bifunctional glycidyl ether diluent (trade name "ED-503" manufactured by ADEKA Corporation), 10 parts by weight of phenolic diluent (trade name "ED-512X" manufactured by ADEKA Corporation), 12 parts by weight of surface-treated calcium carbonate (average particle size 0.07 μm) (Carfosil 15B, manufactured by Maruo Chemical Co., Ltd.), and 3 parts by weight of fibrous mineral (trade name "Wollastonite KSP-NO1" manufactured by Kansai Matec Co., Ltd.).

[0115] The curing agent was prepared by mixing 28 parts by weight of a polyamidoamine curing agent (manufactured by T&K Toka Corporation) under the trade name "Tomide 245," 8 parts by weight of a modified aliphatic amine / polyamidoamine mixed curing agent (manufactured by Adeka Corporation) under the trade name "EH-2300," 22 parts by weight of a coumarone-indene copolymer resin (manufactured by Nitto Chemical Co., Ltd.) under the trade name "Cumarone L-5," 65 parts by weight of calcium carbonate (average particle size 5.0 μm) (BF-200S, manufactured by Bihoku Funka Kogyo Co., Ltd.), 1.5 parts by weight of a fibrous mineral (manufactured by Kansai Matec Co., Ltd.) under the trade name "Wollastonite KSP-NO1," 0.5 parts by weight of a fumed silica (manufactured by Nippon Aerosil Co., Ltd.), and 0.05 parts by weight of a carbon black (manufactured by Denka Company, Ltd.) at 25°C.

[0116] A modified aliphatic amine curing agent (PH-760, manufactured by Chori GLEX Co., Ltd.) was used as a reaction adjuster.

[0117] The prepared base resin, curing agent, and reaction modifier were mixed in a measuring cup at a volume ratio (base resin:curing agent:reaction modifier) ​​of 100:100:5, and stirred with a hand mixer for 1 minute. The amine index was 0.99.

[0118] Using the methods described in 3.(3) Physical Properties above for evaluating adhesion, sheet slippage prevention before adhesive curing, and reactivity at the application site, the resulting solventless adhesive was evaluated for adhesion at low temperatures (5°C), adhesive viscosity at low temperatures (5°C), sheet slippage prevention before adhesive curing, and reactivity at the application site. The results are shown in Table 1. Furthermore, during the adhesion evaluation, failure was visually confirmed. Figure 5 shows the failure state in a shear tensile test performed on a substrate placed under dry conditions at the time of curing and then placed under dry conditions after curing. Figure 6 shows the failure state in a shear tensile test performed on a substrate placed under dry conditions at the time of curing and then placed under wet conditions after curing. Figure 7 shows the failure state in a shear tensile test performed on a substrate placed under wet conditions at the time of curing and then placed under wet conditions after curing. In both cases, the flooring sheet ruptured (sheet rupture), demonstrating good adhesion. The adhesive's viscosity at low temperatures (5°C) was 68.1 Pa·s, demonstrating excellent handleability even at low temperatures. In a friction test after laminating the sheets, the friction force was 103N, showing good slippage prevention and resistance to slippage. The time to reach 60°C, which is an evaluation index for usable time on site, was 50 minutes, and the usable time was 30 minutes or more, which was good. Regarding reactivity on site, the time when tan δ peaked was 4.5 hours, showing good workability in sheet preparation. The time it took for adhesive strength to develop after laminating the sheets was 16 hours, which was good. The evaluation results of workability in sheet preparation and adhesive strength development time showed that reactivity was good.

[0119] [Table 1] (The units in the table are parts by weight.)

[0120] [Example 2]

[0121] A solventless adhesive was prepared in the same manner as in Example 1, except that a modified aliphatic amine / polyamidoamine mixed curing agent, "EH-2300" (manufactured by ADEKA Corporation), was used as the reaction modifier instead of the modified aliphatic amine curing agent (PH-760), and the volume ratio (main agent:curing agent:reaction modifier) ​​was mixed to be 100:100:6. The amine index was 1.066. Reactivity at the construction site was evaluated in the same manner as in Example 1. The results are shown in Table 1. Regarding reactivity at the construction site, the time when tan δ peaked was 4.5 hours, and the workability of sheet preparation was good. The time required for adhesive strength to develop after the sheets were laminated was 24 hours.

[0122] [Example 3]

[0123] A solventless adhesive was prepared in the same manner as in Example 1, except that a tertiary amine-based curing agent (Daitoclar 3010, manufactured by Daito Sangyo Co., Ltd.) was used as the reaction modifier instead of the modified aliphatic amine-based curing agent (PH-760), and the volume ratio (main agent:curing agent:reaction modifier) ​​was 100:100:5. The amine index was 0.87. Reactivity at the construction site was evaluated in the same manner as in Example 1. The results are shown in Table 1. Regarding reactivity at the construction site, the time to peak tan δ was 3.5 hours, indicating good workability in sheet preparation. The time to develop adhesive strength after sheet lamination was 11 hours, indicating good reactivity. However, the strong odor at the construction site made it unsuitable for use as is, and odor control measures were required.

[0124] [Example 4]

[0125] A solventless adhesive was produced in the same manner as in Example 1, except that it did not contain the modified aliphatic amine-based curing agent, which is a reaction modifier. The slippage prevention test and on-site reactivity were evaluated using the same methods as in Example 1. The friction test force was 79 N, and the time to reach 60°C was 75 minutes. The time to peak tan δ was 5 hours, and the workability of sheet adjustment was good. The time to develop adhesive strength after sheet lamination was 24 hours.

[0126] [Comparative Example 1]

[0127] Adhesion was evaluated using a one-component solvent-based urethane adhesive (Rubylon 202, manufactured by Toyo Polymer Co., Ltd.) in the same manner as in Example 1. Furthermore, during the adhesion evaluation, the state of failure was visually confirmed. Figure 8 shows the state of failure in a shear tensile test in which the substrate was placed under dry conditions when cured and then under dry conditions after curing. Figure 9 shows the state of failure in a shear tensile test in which the substrate was placed under dry conditions when cured and then under wet conditions after curing. Figure 10 shows the state of failure in a shear tensile test in which the substrate was placed under wet conditions when cured and then under wet conditions after curing. As shown in Figure 8, when the substrate was placed under dry conditions when cured and then under dry conditions after curing, the flooring sheet ruptured (sheet rupture), demonstrating good adhesion. However, when the substrate was placed under dry conditions during curing and under wet conditions after curing, as shown in Figure 9, and when the substrate was placed under wet conditions during curing and then under wet conditions after curing, as shown in Figure 10, the adhesive peeled off from the substrate, resulting in poor adhesion. Furthermore, in a test to determine the slippage prevention properties of the sheet before adhesive curing using the same method as in Example 1, the friction force after the sheets were bonded together was 119 N.

[0128] Comparative Example 2

[0129] A solventless adhesive was produced in the same manner as in Example 1, except that it did not contain fibrous minerals. The slippage prevention properties of the sheets before the adhesive hardened were evaluated in the same manner as in Example 1. In a friction test after the sheets were bonded together, the friction force was 16 N, which meant that the sheets slipped easily and had poor slippage prevention properties.

[0130] Although the embodiments and examples of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments and examples, and various modifications based on the technical concept of the present invention are possible.

[0131] For example, the configurations, methods, processes, shapes, materials, and numerical values, etc., given in the above-described embodiments and examples are merely examples, and different configurations, methods, processes, shapes, materials, and numerical values, etc., may be used as necessary.

[0132] Furthermore, the configurations, methods, steps, shapes, materials, numerical values, etc. of the above-described embodiments and examples can be combined with one another without departing from the spirit of the present invention.

[0133] Furthermore, in this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit of a numerical range in one stage may be replaced with the upper or lower limit of a numerical range in another stage. Unless otherwise specified, the materials exemplified in this specification can be used alone or in combination of two or more types.

Claims

1. A solventless adhesive set including a base agent containing an epoxy resin and a curing agent that cures the epoxy resin, A solventless adhesive set, wherein at least one of the base agent and the curing agent contains a fibrous mineral.

2. The solventless adhesive set according to claim 1 , further comprising a reaction modifier that modifies the curing reaction of the epoxy resin.

3. The solventless adhesive set according to claim 1, wherein the aspect ratio (L:D) of the fibrous mineral is 2:1 to 30:

1.

4. The solventless adhesive set according to claim 2 , wherein the reaction modifier is an aliphatic amine.

5. The solvent-free adhesive set according to claim 1, which is used in construction work around water.

6. The solvent-free adhesive set according to claim 1, which is used for bonding flooring materials.

7. The solventless adhesive set according to claim 1 , wherein at least one of the base agent and the curing agent further contains an extender pigment.

8. The solventless adhesive set according to claim 1 , wherein at least one of the base agent and the curing agent further contains a black pigment.

9. A base agent used in the solventless adhesive set according to claim 1.

10. A curing agent used in the solventless adhesive set according to claim 1.

11. A reaction adjuster used in the solventless adhesive set according to claim 2.

12. A solventless adhesive comprising a base agent containing an epoxy resin and a curing agent that cures the epoxy resin, A solvent-free adhesive, wherein at least one of the base agent and the curing agent contains a fibrous mineral.

13. The solventless adhesive according to claim 12, further comprising a reaction modifier that modifies the curing reaction of the epoxy resin.

14. A bonding method for bonding objects to be bonded using a solventless adhesive containing a base agent containing an epoxy resin and a curing agent that hardens the epoxy resin, comprising: The bonding method, wherein at least one of the base agent and the curing agent contains a fibrous mineral.

15. The bonding method according to claim 14 , wherein the solventless adhesive further contains a reaction modifier that modulates the curing reaction of the epoxy resin.

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