Temporary fixing agents and temporary fixing supplies

Abstract

The present invention provides a temporary fixing agent and a temporary fixing product comprising the temporary fixing agent. The present invention is a temporary fixing agent used to temporarily fix a member to be polished, wherein the temporary fixing agent contains at least 50 weight% of a polyhydric alcohol that has at least three hydroxyl groups and a molecular weight of 100-1,000.

Description

[Technical Field]

[0001] The present invention relates to a temporary fixing agent for a polished member and a temporary fixing article containing the temporary fixing agent. [Background technology]

[0002] Thin glass has properties such as transparency, high chemical resistance, and heat resistance, and is therefore used in many technical fields, including display devices, touch panels, solar cells, semiconductor modules, and cover glass for LED light sources. For example, soda-lime glass, aluminosilicate glass, borosilicate glass, etc. are used as cover glass for displays. These glasses are chemically strengthened to achieve high mechanical strength such as scratch resistance, and the thickness of the glass for these applications is usually about 0.5 mm to 10 mm. Furthermore, there is a demand for thinner and lighter glass substrates with high strength and flexibility due to demands for new product functionality, etc. Such ultra-thin glass (UTG) is used, for example, as cover glass for smartphones, tablets, watches, and other wearable devices, as cover glass for fingerprint sensor modules, and as camera lens covers (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2016-521247 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-119810 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, thin glass is produced by cutting and separating larger glass sheets into smaller thin glass sheets, but as the glass sheet becomes thinner, defects such as cracks and chips on the glass edges become more likely to occur, making handling more difficult.Usually, in the case of thicker glass, defects such as chips that occur during cutting and separation can be removed by a computer-controlled edge polishing process, but it is difficult to apply mechanical polishing directly to ultra-thin glass. For this reason, the glass sheets are temporarily fixed together to make them thicker to facilitate processing and to enable multiple sheets to be simultaneously subjected to mechanical processing such as cutting, polishing, grinding, etc.

[0005] For such temporary fixing, hot melt adhesives such as wax and rosin are mainly used (for example, Patent Document 2).

[0006] However, although such hot melt adhesives can be easily bonded by heating, they immediately harden when the temperature drops, making it difficult to position them during bonding. Furthermore, when peeling them off, they require cleaning with acids, alkalis, organic solvents, or in some cases halogenated organic solvents, which can cause problems such as a deterioration of the working environment and environmental pollution. Furthermore, there are problems such as contamination of the glass surface due to adhesive residue and damage during peeling. For this reason, there is a demand for a temporary fixing agent that can be peeled off by a simpler method and can be removed more easily.

[0007] An object of the present invention is to provide a temporary fixing agent that can be easily peeled off and removed with water when used for temporarily fixing a workpiece to be polished, and that has a low environmental impact because the surface of the workpiece can be cleaned by rinsing with water. Another object of the present invention is to provide a temporary fixing article containing the temporary fixing agent. [Means for solving the problem]

[0008] The present invention relates to a temporary fixing agent used for temporarily fixing a polished member, which contains 50% by weight or more of a polyhydric alcohol having three or more hydroxyl groups and a molecular weight of 100 or more and 1000 or less. The present invention will be described in detail below.

[0009] The present inventors have discovered that by using a temporary fixing agent containing a specific polyhydric alcohol in a predetermined ratio for temporarily fixing a polished member, the agent can be easily peeled off with water and can be easily removed from the surface of the polished member by rinsing with water. Furthermore, they have discovered that this eliminates the need for conventional cleaning with organic solvents, making it possible to create a temporary fixing agent with a low environmental impact, and have completed the present invention.

[0010] The temporary fixing agent of the present invention contains a polyhydric alcohol having three or more hydroxyl groups and a molecular weight of 100 or more and 1000 or less (hereinafter also referred to as the polyhydric alcohol of the present invention). The polyhydric alcohol according to the present invention has three or more hydroxyl groups. The number of hydroxyl groups is preferably 4 or more, and is preferably 14 or less, and more preferably 11 or less. The polyhydric alcohol according to the present invention may be a mixture of multiple polyhydric alcohols each having three or more hydroxyl groups.

[0011] The molecular weight of the polyhydric alcohol according to the present invention is 100 or more, preferably 110 or more, and more preferably 120 or more, and 1000 or less, preferably 800 or less, more preferably 520 or less, even more preferably 360 or less, and even more preferably 250 or less. By adjusting the amount within the above range, removability by washing with water can be improved. The molecular weight of the polyhydric alcohol refers to a calculated molecular weight. When the polyhydric alcohol is a polymer, the molecular weight refers to a weight-average molecular weight. The weight-average molecular weight (Mw) and number-average molecular weight (Mn) can be measured, for example, by gel permeation chromatography (GPC), using polystyrene as a standard and columns such as TSKgel (Tosoh Corporation), PLgel (AMR Corporation), KF-806, KF-807 (Shodex Corporation), etc.

[0012] In one embodiment of the present invention, when the polyhydric alcohol according to the present invention is a mixture of multiple polyhydric alcohols, the molecular weight of the polyhydric alcohol according to the present invention means the average molecular weight calculated by the following formula (1).

[0013]

number

[0014] In a more preferred embodiment of the present invention, when the polyhydric alcohol according to the present invention is a mixture of multiple polyhydric alcohols, the molecular weight of the polyhydric alcohol is preferably 100 or more, more preferably 110 or more, even more preferably 120 or more, and is preferably 1000 or less, more preferably 800 or less, even more preferably 520 or less, even more preferably 360 or less, and particularly preferably 250 or less. By keeping the molecular weight within the above range, removability by washing with water can be improved.

[0015] The polyhydric alcohol according to the present invention has increased water solubility and can be more easily removed by washing with water, so that the value obtained by dividing the molecular weight by the number of hydroxyl groups (hydroxyl value) is preferably 20 or more, more preferably 25 or more, even more preferably 28 or more, even more preferably 30 or more, preferably 70 or less, more preferably 65 or less, even more preferably 60 or less, even more preferably 55 or less, and particularly preferably 50 or less.

[0016] Furthermore, when the polyhydric alcohol according to the present invention is a mixture of multiple polyhydric alcohols, it is preferable that the value (hydroxyl value) obtained by dividing the molecular weight of each component of the polyhydric alcohol constituting the mixture by the number of hydroxyl groups of each component satisfies the above range.

[0017] The polyhydric alcohol according to the present invention preferably has a flow-initiation temperature of 35°C or higher. If the flow initiation temperature is 35°C or higher, the composition can be solidified at room temperature by cooling and solidifying, thereby enabling temporary fixation. The flow initiation temperature is more preferably 40° C. or higher, even more preferably 45° C. or higher, even more preferably 50° C. or higher, and particularly preferably 55° C. or higher. The upper limit of the flow initiation temperature is preferably 150° C. or lower, more preferably 120° C. or lower, and even more preferably 100° C. or lower. The flow initiation temperature can be measured using a rheometer (a dynamic viscoelasticity measuring device). For example, measurements can be made using a cone plate with a diameter of 20.0 mm and a cone angle of 0.996111°, with a shear rate of 1000 [1 / s] and a heating rate of 10°C / min.

[0018] When the polyhydric alcohol according to the present invention is a mixture of multiple polyhydric alcohols, it is preferable that the flow initiation temperature of the polyhydric alcohol mixture as a whole is within the above range. Furthermore, it is sufficient that the flow initiation temperature of the polyhydric alcohol mixture as a whole is within the above range, and the polyhydric alcohol mixture may contain a polyhydric alcohol component having a flow initiation temperature of less than 35° C. In a more preferred embodiment of the present invention, when the polyhydric alcohol according to the present invention is a mixture of multiple polyhydric alcohols, it is more preferable that the flow initiation temperature of each of the polyhydric alcohol components is within the above range. Generally, for low molecular weight substances with a monodisperse molecular weight distribution, the flow initiation temperature and melting point are substantially the same or close to each other, but for mixtures with a molecular weight distribution, there may be a difference between the flow initiation temperature and the melting point. With the temporary fixing material of the present invention, it is important to focus on the flow initiation temperature rather than the melting point from the perspective of fixing the polished object.

[0019] Examples of the polyhydric alcohol according to the present invention include aliphatic polyols and aromatic polyols. The polyhydric alcohol according to the present invention may also be a sugar such as a disaccharide such as a monosaccharide, heterodisaccharide, or homodisaccharide, a polysaccharide of trisaccharide or more, or a derivative thereof such as an amino sugar, a sugar alcohol, or an uronic acid. Of these, aliphatic polyols are preferred, and sugar alcohols are more preferred.

[0020] The polyhydric alcohol according to the present invention preferably contains a polyhydric alcohol (A) having a flow starting temperature of 85°C or higher and a polyhydric alcohol (B) having a flow starting temperature of 65°C or lower. The above-described structure further enhances water solubility, allowing for easier removal by rinsing with water, and also makes it possible to control the flow initiation temperature of the entire polyhydric alcohol according to the present invention, and to easily control the flow and solidification behavior during temporary fixation.

[0021] Examples of the polyhydric alcohol according to the present invention include polyhydric alcohols (A) having a flow initiation temperature of 85°C or higher, such as trihydric alcohols (e.g., phloroglucinol (218°C)) and tetrahydric alcohols (e.g., ditrimethylolpropane (109°C), erythritol (121°C), threitol (88°C), and pentaerythritol (260°C). Other examples include pentahydric alcohols (e.g., xylitol (92°C), arabitol (103°C), fucitol (153°C), glucose (146°C), and fructose (104°C), and hexahydric alcohols (e.g., mannitol (166°C), sorbitol (95°C), and inositol (225°C). Other examples include octahydric alcohols (e.g., lactitol (146°C), sucrose (186°C), and trehalose (97°C), and nonahydric or higher alcohols (e.g., maltitol (145°C). The values ​​in parentheses indicate the flow initiation temperature. Among the above, those having a flow initiation temperature of 90° C. or higher are preferred. The flow initiation temperature of the polyhydric alcohol (A) is preferably 230° C. or lower, and more preferably 195° C. or lower.

[0022] Examples of the polyhydric alcohol (B) having a flow-initiation temperature of 65° C. or less include trihydric alcohols such as trimethylolpropane (58° C.) and triethanolamine (21° C.). Among the above, those having a flow initiation temperature of 60° C. or less are preferred. Furthermore, the polyhydric alcohol (B) is preferably a solid at room temperature, and the flow initiation temperature is preferably 30° C. or more, more preferably 40° C. or more.

[0023] In the temporary fixing agent of the present invention, the weight ratio of the polyhydric alcohol (A) to the polyhydric alcohol (B) (polyhydric alcohol (A):polyhydric alcohol (B)) is preferably 8:1 to 1:1, more preferably 6:1 to 2:1, and even more preferably 4:1 to 3:2. By setting the content within the above range, the function of being temporarily fixed by cooling and solidifying can be exhibited, and the adhesive can be more easily removed by washing with water.

[0024] The content of the polyhydric alcohol according to the present invention in the temporary fixing agent of the present invention is 50% by weight or more. By adjusting the thickness within the above range, the film can be easily peeled off with water and can be easily removed by washing with water. The content is preferably 70% by weight or more, more preferably 75% by weight or more, even more preferably 80% by weight or more, and even more preferably 85% by weight or more. There is no upper limit, but the content is preferably 100% by weight or less, and more preferably 97% by weight or less.

[0025] The total content of the polyhydric alcohols (A) and (B) in the polyhydric alcohol of the present invention is preferably 0% by weight or more, more preferably 50% by weight or more, even more preferably 70% by weight or more, and even more preferably 80% by weight or more. There is no upper limit, but it is preferably 100% by weight or less.

[0026] The temporary fixing agent of the present invention may contain a polyhydric alcohol other than the polyhydric alcohol of the present invention (hereinafter also referred to as other polyhydric alcohol). Examples of the other polyhydric alcohols include dihydric alcohols and polyhydric alcohols of less than 100 with a molecular weight of 3 or more. Specific examples of dihydric alcohols include salicylic alcohol (83°C), catechol (105°C), resorcinol (110°C), hydroquinone (172°C), bisphenol A (158°C), bisphenol F (162°C), neopentyl glycol (127°C), ethylene glycol (-13°C), and diethylene glycol (-11°C). Other examples include triethylene glycol (-7°C), propylene glycol (-59°C), tetraethylene glycol (-5.6°C), 1,3-propanediol (-27°C), 1,4-butanediol (20°C), 1,6-hexanediol (40°C), and tripropylene glycol (-30°C). Examples of trihydric or higher polyhydric alcohols having a molecular weight of less than 100 include glycerin.

[0027] The temporary fixing agent of the present invention may further contain a water-soluble resin. By including the water-soluble resin, it is possible to suppress a decrease in adhesive strength over time. Examples of the water-soluble resin include nonionic polymers such as polyvinyl alcohol, polyvinyl acetal, polyacrylamide, polyethylene oxide, polymethyl vinyl ether, and polyisopropylacrylamide; anionic polymers such as poly(sodium acrylate) and copolymers thereof, poly(sodium styrene sulfonate), poly(sodium isoprene) copolymers, naphthalene sulfonic acid condensate salts, and polyethyleneimine xanthate salts; homopolymers and copolymers of dimethylaminoethyl (meth)acrylate quaternary salts; homopolymers and copolymers of dimethyldiallylammonium chloride; polyamidine and copolymers thereof; polyvinyl imidazoline; dicyandiamide condensates; epichlorohydrin dimethylamine condensates; Examples of the polymer include cationic polymers such as polyethyleneimine, acrylic resins, polyester resins, polyurethane resins, polyether resins, polyalkylene glycols, polyvinylpyrrolidone and copolymers thereof, starch and its derivatives such as starch, carboxymethyl starch, starch phosphate and cationic starch, polysaccharides such as cellulose derivatives such as dextrin, cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and carboxymethyl cellulose, and polymers derived from natural products such as cellulose guar gum, xanthan gum, alginic acid, gum arabic, carrageenan, sodium chondroitin sulfate, sodium hyaluronate, chitosan and gelatin. Further examples include modified polyvinyl alcohols and modified polyvinyl acetals obtained by modifying the above polyvinyl alcohols and polyvinyl acetals, etc. Among these, polyvinyl alcohols and modified polyvinyl alcohols are preferred. The water-soluble resin may also be a resin having a hydroxyl group added thereto, such as a hydroxyl-containing acrylic resin, a hydroxyl-containing polyester resin, a hydroxyl-containing polyurethane resin, or a hydroxyl-containing polyether resin. The water-soluble resin refers to a resin that dissolves at 95% by weight or more when dissolved in water at 23°C.

[0028] When polyvinyl alcohol (hereinafter also referred to as PVA) is used as the water-soluble resin, the saponification degree of the PVA preferably has a lower limit of 50 mol% and an upper limit of 100 mol%. By ensuring that the saponification degree is equal to or greater than the lower limit, physical strength can be more effectively exhibited when formed into a film. The saponification degree of the PVA used is appropriately determined depending on the balance between the desired physical properties and water solubility. The lower limit of the degree of saponification is more preferably 70 mol %, even more preferably 80 mol %, and the upper limit is more preferably 99.5 mol %, even more preferably 99 mol %. The saponification degree can be measured in accordance with JIS K 6726. The saponification degree indicates the proportion of units that are actually saponified into vinyl alcohol units among units that are converted into vinyl alcohol units by saponification. The method for adjusting the saponification degree is not particularly limited, and the saponification degree can be appropriately adjusted by the saponification conditions, i.e., the hydrolysis conditions.

[0029] The degree of polymerization of the PVA is not particularly limited, but the lower limit is preferably 250, more preferably 300, and the upper limit is preferably 5000, more preferably 2700. The degree of polymerization can be measured in accordance with JIS K6726.

[0030] The PVA may be a mixture of two or more PVAs with different degrees of saponification, polymerization, etc., or a mixture of modified and unmodified PVAs. By using such a mixed PVA, the resin with a low degree of saponification or the modified PVA exhibits the effect of lowering the actual flow temperature, thereby further improving the balance between water solubility and adhesive strength.

[0031] The polyvinyl alcohol is obtained by polymerizing a vinyl ester to obtain a polymer according to a conventionally known method, and then saponifying, i.e., hydrolyzing, the polymer. An alkali or an acid is generally used for the saponification. An alkali is preferably used for the saponification. The polyvinyl alcohol may be used alone or in combination of two or more kinds.

[0032] Examples of the vinyl ester include vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl versatate, vinyl laurate, vinyl stearate, and vinyl benzoate. The polymer obtained by polymerizing the vinyl ester is preferably a polyvinyl ester, since the degree of saponification can be easily controlled within a suitable range.

[0033] The polymerization method for the vinyl ester is not particularly limited, and examples of the polymerization method include solution polymerization, bulk polymerization, and suspension polymerization.

[0034] Examples of polymerization catalysts used in polymerizing the vinyl ester include 2-ethylhexyl peroxydicarbonate (TrigonoxEHP manufactured by Tianjin McEIT Co., Ltd.), 2,2'-azobisisobutyronitrile (AIBN), t-butyl peroxyneodecanoate, bis(4-t-butylcyclohexyl)peroxydicarbonate, di-n-propyl peroxydicarbonate, di-n-butyl peroxydicarbonate, di-cetyl peroxydicarbonate, and di-s-butyl peroxydicarbonate. One type of the polymerization catalyst may be used alone, or two or more types may be used in combination.

[0035] The polyvinyl alcohol includes modified polyvinyl alcohol (modified PVA). The modified PVA may be a copolymer of the vinyl ester and another monomer, or may be a modified polyvinyl alcohol. Examples of the modified polyvinyl alcohol include amine-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, carboxyl-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, olefin-modified polyvinyl alcohol, nitrile-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, pyrrolidone-modified polyvinyl alcohol, modified polyvinyl alcohol containing silicon atoms, and graft polymers of copolymers of polyvinyl alcohol and (acrylamide, vinylpyrrolidone, acrylonitrile). Of these, unmodified polyvinyl alcohol, pyrrolidone-modified polyvinyl alcohol, amine-modified polyvinyl alcohol, and sulfonic acid-modified polyvinyl alcohol are preferred, with unmodified polyvinyl alcohol being more preferred.

[0036] Examples of the other monomer, i.e., the comonomer to be copolymerized, include olefins, (meth)acrylic acid and salts thereof, (meth)acrylic acid esters, (meth)acrylamide derivatives, N-vinylamides, vinyl ethers, nitriles, vinyl halides, allyl compounds, maleic acid and salts thereof, maleic acid esters, itaconic acid and salts thereof, itaconic acid esters, vinylsilyl compounds, polyvinylpyrrolidone, and isopropenyl acetate. The other monomers may be used alone or in combination of two or more.

[0037] Examples of the olefins include ethylene, propylene, 1-butene, and isobutene. Examples of the (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Examples of the (meth)acrylamide derivatives include acrylamide, n-methylacrylamide, N-ethylacrylamide, N,N-dimethylacrylamide, (meth)acrylamidopropanesulfonic acid and salts thereof. Examples of the N-vinylamides include N-vinylpyrrolidone. Examples of the vinyl ethers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, and n-butyl vinyl ether. Examples of the nitriles include (meth)acrylonitrile. Examples of the vinyl halides include vinyl chloride and vinylidene chloride. Examples of the allyl compound include allyl acetate and allyl chloride. Examples of the vinylsilyl compound include vinyltrimethoxysilane.

[0038] The upper limit of the modification amount (proportion of modified structural units) in the modified polyvinyl alcohol is preferably 25 mol%, more preferably 20 mol%, and even more preferably 15 mol%. The lower limit of the modification amount is preferably 2 mol%. By keeping the modification amount within the above range, the balance between water solubility and adhesive strength can be further improved.

[0039] The content of the water-soluble resin (particularly polyvinyl alcohol) in the temporary fixing agent of the present invention is preferably 2% by weight or more and 15% by weight or less. By setting the content within the above range, the balance between water solubility and adhesive strength can be further improved. The content of the water-soluble resin is more preferably 3% by weight or more, even more preferably 4% by weight or more, and more preferably 13% by weight or less, even more preferably 11% by weight or less.

[0040] In the temporary fixing agent of the present invention, the content of the water-soluble resin relative to 100 parts by weight of the total amount of the polyhydric alcohol of the present invention is preferably 2 parts by weight or more, more preferably 3 parts by weight or more, and even more preferably 4 parts by weight or more, and is preferably 55 parts by weight or less, more preferably 35 parts by weight or less, even more preferably 20 parts by weight or less, even more preferably 15 parts by weight or less, and particularly preferably 10 parts by weight or less.

[0041] The temporary fixing agent of the present invention may contain other components such as a storage stabilizer, a mechanical property improver, a thickener, an antiseptic, an antifungal agent, a dispersion stabilizer, and a spacer (gap adjusting material). Examples of storage stabilizers include polycarboxylic acids such as citric acid, malic acid, tartaric acid, succinic acid, and erythorbic acid. Examples of the mechanical property improver include (meth)acrylic acid, maleic acid, (meth)acrylic acid amide, acrylonitrile, hydroxyethyl (meth)acrylate, furfuryl alcohol, and glycidyl (meth)acrylate. Examples of thickeners include inorganic thickeners such as clay, talc, and silica, and organic thickeners such as natural thickeners such as plant powder wheat flour, corn starch, rice flour, walnut flour, and coconut flour. Examples of gap adjustment materials include glass beads, resin microparticles, silica particles, and metal particles with controlled particle size. However, it is preferable to use a material that is less hard than the member to be fixed, so as not to damage the surface of the member to be fixed, such as ultra-thin glass.

[0042] The method for producing the temporary fixing agent of the present invention is not particularly limited, and examples thereof include a method in which the polyhydric alcohol according to the present invention, such as the polyhydric alcohol (A) and the polyhydric alcohol (B), other polyhydric alcohols, water-soluble resins, other additives, and the like, are mixed using a mixer. Examples of the mixer include a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, and a three-roll mixer. Another example is a method in which an aqueous solution containing a water-soluble resin and an aqueous solution containing the polyhydric alcohol according to the present invention, such as the polyhydric alcohol (A) and the polyhydric alcohol (B), are mixed together, and the water is removed by drying or the like. Further, there is also mentioned a method in which the polyhydric alcohol according to the present invention, such as the polyhydric alcohol (A) and the polyhydric alcohol (B), other polyhydric alcohols, water-soluble resins, other additives, etc. are mixed in water, and the water is removed by drying. Other examples include a method in which the polyhydric alcohol according to the present invention, such as the polyhydric alcohol (A) or the polyhydric alcohol (B), is mixed with an aqueous solution containing a water-soluble resin, and the water is removed by drying. The drying method includes natural drying and heat drying. In either of the above methods, the mixture may be heated and mixed as needed.

[0043] The temporary fixing agent of the present invention can be used when performing a polishing process on a temporarily fixed member to be polished (for example, the surface, side, etc. of a member to be polished). In particular, the temporary fixing agent of the present invention can be used to temporarily fix a member to be polished, such as glass, when multiple pieces of glass, such as ultra-thin glass, are cut simultaneously and the side surfaces are polished. Furthermore, the member to be polished is not limited to glass. The temporary fixing agent of the present invention can be used, for example, in the manufacture of semiconductor devices such as semiconductor chips and display devices, or electronic components, when fixing an adherend such as a wafer or semiconductor chip to perform processing such as polishing, and has a function as a protective material for protecting the wafer or semiconductor chip.

[0044] As a method for temporary fixing using the temporary fixing agent of the present invention, for example, a method can be mentioned in which the temporary fixing agent of the present invention is melted, dropped onto a member to be fixed such as glass, and then bonded to another member to be fixed, followed by cooling and solidification. Another example is a method in which a temporary fixing article containing the temporary fixing agent of the present invention is placed between members to be fixed, heated, and then cooled and solidified.

[0045] The temporary fixing agent can be removed to separate the fixed member by washing with water, and ultrasonic cleaning is preferably used for the water washing. In addition, the temporary fixing agent can be removed more easily by using warm water in the above washing with water, or by using warm water in combination with ultrasonic waves.

[0046] Examples of methods for producing the temporary fixing article include a method in which the temporary fixing agent of the present invention is applied to a substrate and then molded into a sheet or the like, and a method in which the temporary fixing agent of the present invention is impregnated into a substrate. The present invention also provides a temporary fixing article comprising a porous substrate containing the temporary fixing agent of the present invention. In a preferred embodiment, there are provided a temporary fixing article in which a layer made of the temporary fixing agent is laminated on a substrate, and a temporary fixing article in which the temporary fixing agent is impregnated into a substrate.

[0047] Examples of materials that can be used to form the substrate include polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyacetal, polyamide, polycarbonate, polyphenylene ether, polybutylene terephthalate, ultra-high molecular weight polyethylene, syndiotactic polystyrene, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polyetherimide, fluororesin, and liquid crystal polymer. In addition, examples of the substrate that can be used include synthetic fibers such as polyethylene fibers, polypropylene fibers, and polyester fibers; glass fibers, carbon fibers, and metal fibers; fibrous materials such as woven fabrics made of paper, cotton, and hemp, nonwoven fabrics, chopped strand mats, and roving cloth; and porous substrates such as foamable materials such as polyurethane foam and polyethylene foam. Examples of nonwoven materials include polyester, high-density polyethylene (HDPE), polypropylene, etc. Flexible and porous felts, mats, spunbonds, webs, etc., having continuous filaments or staple fibers can also be used. Examples of chopped strand mats include those obtained by cutting strands of glass fiber or the like to a certain length, dispersing them in a mat, and then uniformly applying an adhesive such as a thermoplastic resin and heat-melting the resulting mixture to bond the strands together to form a mat. Examples of roving cloth include those made of reinforcing fibers such as glass fiber, carbon fiber, aramid fiber, inorganic fiber, organic fiber, and whisker. In a preferred embodiment of the present invention, the porous substrate preferably comprises, and more preferably is, a fibrous material.

[0048] The shape of the substrate is not particularly limited, and thin shapes such as films, sheets, and plates can be used. The thickness of the substrate is not particularly limited, but is preferably 5 μm or more, more preferably 10 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less. In addition, since the substrate also functions as a spacer for bonding multiple glass substrates or the like in parallel, it is also important to select a thickness that suits the purpose.

[0049] According to another embodiment of the present invention, there is also provided use of the temporary fixing agent for temporarily fixing the polished member. [Effects of the Invention]

[0050] According to the present invention, it is possible to provide a temporary fixing agent that can be easily peeled off and removed with water when used for temporarily fixing a workpiece to be polished, and that has a low environmental impact because the surface of the workpiece can be cleaned by rinsing with water.It is also possible to provide a temporary fixing article containing the temporary fixing agent. DETAILED DESCRIPTION OF THE INVENTION

[0051] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0052] Example 1 50 parts by weight of the polyhydric alcohol erythritol (molecular weight 122.1, flow onset temperature 121°C, number of hydroxyl groups 4) and 50 parts by weight of trimethylolpropane (molecular weight 134.2, flow onset temperature 58°C, number of hydroxyl groups 3) were dissolved and mixed in 300 parts by weight of water while heating to 80°C, and then the mixture was spread on a stainless steel tray and dried and dehydrated in a hot air circulating dryer at 120°C to obtain a temporary fixing agent. The flow initiation temperature of the polyhydric alcohol was measured using a rheometer (manufactured by TA Instruments, HR-10).

[0053] Example 2 A temporary fixing agent was obtained in the same manner as in Example 1, except that 75 parts by weight of erythritol and 25 parts by weight of trimethylolpropane were used.

[0054] Example 3 An aqueous polyvinyl alcohol solution was prepared by adding 10 parts by weight of the water-soluble resin polyvinyl alcohol (PVA1: Sekisui Specialty Chemicals' "Selvol 103," average degree of polymerization 250, degree of saponification 98.4 mol%) to 300 parts by weight of water. The resulting aqueous polyvinyl alcohol solution, 70 parts by weight of erythritol, and 20 parts by weight of trimethylolpropane were mixed while heating to 80°C, and then the mixture was spread thinly on a stainless steel tray and dried in a hot air circulating dryer at 120°C to remove the water, yielding a temporary fixing agent.

[0055] Example 4 An aqueous polyvinyl alcohol solution was prepared by adding 5 parts by weight of a water-soluble resin, polyvinyl alcohol (PVA1: Sexis Specialty Chemicals' "Selvol 103," average polymerization degree 250, saponification degree 98.4 mol%), to 300 parts by weight of water. A temporary fixing agent was obtained in the same manner as in Example 3, except that the obtained aqueous polyvinyl alcohol solution, 75 parts by weight of erythritol, and 20 parts by weight of trimethylolpropane were mixed.

[0056] Example 5 A temporary fixing agent was obtained in the same manner as in Example 4, except that polyvinyl alcohol (PVA-2: Sexis Specialty Chemicals' "Selvol 205", average polymerization degree 500, saponification degree 88 mol%) was used as the water-soluble resin.

[0057] Example 6 Trimethylolpropane (molecular weight 134.2, flow starting temperature 58°C) was used as a temporary fixing agent.

[0058] (Comparative Example 1) Paraffin Wax-145 (manufactured by Nippon Seiro Co., Ltd.) was used as a temporary fixative.

[0059] (Comparative Example 2) Paraffin wax HNP-9 (Nippon Seiro Co., Ltd., composition paraffin) was used as a temporary fixative.

[0060] (Comparative Example 3) Microcrystalline wax HiMic-1080 (manufactured by Nippon Seiro Co., Ltd.) was used as a temporary fixative.

[0061] The paraffin waxes used in the comparative examples (Paraffin Wax-145, Paraffin Wax HNP-9) are white waxes that are solid at room temperature and are generally refined petroleum products whose main component is a linear hydrocarbon (normal paraffin) with a molecular weight of 300 to 550, and do not contain hydroxyl groups. Microcrystalline wax HiMic-1080 is a wax that is solid at room temperature and generally contains a main component of a hydrocarbon (isoparaffin) with a side chain on a main chain with a molecular weight of 500 to 800, with small amounts of linear hydrocarbons and cyclic hydrocarbons, and does not contain hydroxyl groups.

[0062] <Evaluation> The following evaluations were carried out for the Examples and Comparative Examples, and the results are shown in Table 1.

[0063] (1) Adhesive strength Two glass slides (Matsunami Glass Industry Co., Ltd., product name: White Edge Polished No. 2, length 76 mm x width 26 mm x thickness 1.1 mm) were prepared. The two glass slides and temporary fixative were heated to 120°C, and the temporary fixative was dropped onto one edge of one glass slide. The other glass slide was then placed horizontally on a SUS plate so that they overlapped over an area of ​​25 mm x 26 mm. Another SUS plate was used to apply 10 g / cm 2 The two sheets of glass were bonded together under a pressure of 1000 kJ / cm to obtain a laminate. After the laminate was cooled, the temporary fixing agent that had protruded from the glass was scraped off with a cutter knife to obtain a test piece. The obtained test piece was pulled at a pulling speed of 5 mm / min using a universal tensile tester ("AUTOGRAPH AGS-J" manufactured by Shimadzu Corporation), and the stress at the time of peeling was calculated to determine the initial adhesive strength (N / mm 2 ) was measured. The test pieces were stored at a temperature of 23°C and a humidity of 50% for 7 days, and the adhesive strength over time (N / mm 2 ) was measured. Furthermore, the rate of change (%) in adhesive strength over time was calculated according to the following formula. Change in adhesive strength over time (%) = [(adhesive strength over time - initial adhesive strength) / initial adhesive strength] x 100

[0064] (2) Water-soluble A 300 ml beaker was charged with 200 ml of 25°C pure water and a stirrer, which was then stirred at 300 rpm using a magnetic stirrer. Five grams of flake-shaped temporary fixing agent was then added to the beaker, and the mixture was stirred for 10 minutes in the same manner. The state after stirring was visually confirmed, and the evaluation was made as "Good" when the temporary fixative was almost completely dissolved, and "Poor" when most of the temporary fixative remained dissolved as floating matter.

[0065] (3) Residual rate after washing (3-1) Ultrasonic cleaning Test pieces were obtained in the same manner as in "(1) Adhesive strength." A 300 ml beaker was filled with 300 ml of pure water, and the test specimen was placed upright in the beaker so that the bonded area was submerged. The beaker was then placed in an ultrasonic cleaner, and ultrasonic waves were applied at 45 kHz for 30 minutes. After 30 minutes, the test specimen was removed, and the dissolution rate (%) during ultrasonic cleaning was measured by calculating the ratio of the area of ​​the area where the temporary fixative had dissolved to the area of ​​the entire bonded area (25 mm x 26 mm).

[0066] (3-2) Warm water washing Test pieces were obtained in the same manner as in "(1) Adhesive strength." A 300 ml beaker was placed in a water bath equipped with a magnetic stirrer, containing 300 ml of pure water and a stirring bar. Stirring was started at 300 rpm, and the temperature of the water bath was adjusted so that the water temperature in the beaker was 80 ± 2°C. After confirming that the water temperature had reached 80 ± 2°C, the test specimen was placed upright in the beaker so that the bonded area was submerged. After 30 minutes, the test specimen was removed, and the dissolution rate (%) upon washing with warm water was measured by calculating the ratio of the area of ​​the area where the temporary fixative had dissolved to the total area of ​​the bonded area (25 mm x 26 mm). In addition, the samples with a rating of "×" for "(2) Water solubility" were not evaluated.

[0067] [Table 1] [Industrial Applicability]

[0068] According to the present invention, it is possible to provide a temporary fixing agent that can be easily peeled off and removed with water when used for temporarily fixing a workpiece to be polished, and that has a low environmental impact because the surface of the workpiece can be cleaned by rinsing with water.It is also possible to provide a temporary fixing article containing the temporary fixing agent.

Claims

1. A temporary fixing agent used for temporarily fixing a polished member, comprising: The composition contains 50% by weight or more of a polyhydric alcohol having three or more hydroxyl groups and a molecular weight of 100 to 1,000, The polyhydric alcohol has a hydroxyl value (a value obtained by dividing the molecular weight by the number of hydroxyl groups) of 28 or more and 70 or less.

2. 2. The temporary fixing agent according to claim 1, wherein the polyhydric alcohol is a mixture of a plurality of polyhydric alcohols, and the average molecular weight calculated by the following formula (1) is 100 or more and 1,000 or less. [Equation 1] However, the mixing ratio of each polyhydric alcohol is expressed by weight ratio, and the total is 1.

3. The temporary fixing agent according to claim 1 or 2, wherein the polyhydric alcohol has a flow-initiation temperature of 35°C or higher.

4. The temporary fixing agent according to any one of claims 1 to 3, wherein the polyhydric alcohol contains a polyhydric alcohol (A) having a flow initiation temperature of 85°C or higher and a polyhydric alcohol (B) having a flow initiation temperature of 65°C or lower, and the weight ratio of the polyhydric alcohol (A) to the polyhydric alcohol (B) is 8:1 to 1:

1.

5. The temporary fixing agent according to any one of claims 1 to 4, comprising 2% by weight or more and 15% by weight or less of a water-soluble resin.

6. A temporary fixing article comprising a porous substrate containing the temporary fixing agent according to any one of claims 1 to 5.

7. The temporary fastening article according to claim 6 , wherein the porous substrate comprises a fibrous material.

8. The temporary fastening article according to claim 6 or 7, wherein the porous substrate is in the form of a film or sheet.

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