JP2011132534A - Pressure-sensitive adhesive for removing tiny foreign matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive for removing tiny foreign matter, comprising a polyurethane composition provided with proper pressure-sensitive adhesiveness and excellent separability. <P>SOLUTION: The pressure-sensitive adhesive for removing the tiny foreign matter, comprising the polyurethane composition is obtained by crosslinking-reacting a polyether polyol having 20-200 mgKOH/g of hydroxyl value, 2.5-4.0 of average functional group number, and 8-20% of EO content, and an aromatic polyisocyanate having 2.0-2.5 of average functional group number. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pressure-sensitive adhesive for removing fine foreign substances comprising a polyurethane composition. More specifically, for example, the present invention relates to an adhesive for removing fine foreign substances made of a polyurethane composition that is suitably used as an adhesive used for removing fine foreign substances adhering to OA equipment, semiconductor wafer surfaces, and the like.

  Conventionally, as a method for removing minute foreign matter adhering to the surface of OA equipment, semiconductor wafers, etc., the adhesive is applied to the base or the tip of the support rod is used for the adhesive. A method for adhering foreign matter has been proposed. As a specific example, there is a stick-like member in which an adhesive removal portion made of a substantially spherical urethane-based adhesive or the like is formed at the tip of a support rod (see Patent Document 1).

  Adhesive used in the above applications has moderate adhesiveness that can remove minute foreign matter, and excellent peeling that does not cause adhesive residue on objects such as OA equipment and semiconductor wafer surfaces that are trying to remove foreign matter At the same time, the development of urethane-based pressure-sensitive adhesives having such properties is required. However, a urethane-based adhesive having appropriate tackiness and excellent peelability at the same time has not been obtained.

JP 2000-166853 A

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a pressure-sensitive adhesive for removing minute foreign substances, which is made of a polyurethane composition having both moderate adhesiveness and excellent peelability.

  In order to solve the above problems, the present invention provides a polyether polyol having a hydroxyl value of 20 to 200 mg KOH / g, an average functional group number of 2.5 to 4.0, and an EO content of 8 to 20%. The present invention also relates to a pressure sensitive adhesive for removing fine foreign substances, which is made of a polyurethane composition obtained by crosslinking reaction with an aromatic polyisocyanate having an average functional group number of 2.0 to 2.5.

  The pressure sensitive adhesive for removing minute foreign substances made of the polyurethane composition of the present invention has both moderate tackiness and excellent peelability at the same time. Therefore, the pressure-sensitive adhesive for removing fine foreign substances comprising the polyurethane composition of the present invention can be suitably used particularly as a pressure-sensitive adhesive used for removing fine foreign substances adhering to OA equipment, semiconductor wafer surfaces, etc. It is.

Microscope photograph showing the surface state of the semiconductor wafer before and after the operation when the adhesive part made of the polyurethane composition obtained in Example 3 was lightly pressed against the surface of the semiconductor wafer and then peeled off several times. (Magnification: 150 times). Microscope photograph showing the surface state of the semiconductor wafer before and after the operation when the adhesive part made of the polyurethane composition obtained in Comparative Example 5 was lightly pressed against the surface of the semiconductor wafer and then peeled off several times. (Magnification: 150 times). Microscope photograph showing the surface state of the semiconductor wafer before and after the operation when the adhesive part made of the polyurethane composition obtained in Comparative Example 15 was lightly pressed against the surface of the semiconductor wafer and then peeled off several times. (Magnification: 150 times).

  The polyurethane composition of the present invention can be obtained by reacting a polyol or a premix containing the polyol with an isocyanate.

  The polyol is not particularly limited as long as it has two or more hydroxyl groups in the molecule. Polyether polyol, polyester polyol, polycarbonate polyol, polylactone polyol, polyolefin polyol, acrylic polyol, castor oil-based polyol, silicone Examples thereof include polymer polyols, polymer polyols modified with an ethylenically unsaturated monomer, and the like, and these can be used alone or in admixture of two or more.

  Examples of the polyether polyol include compounds obtained by subjecting an active hydrogen compound such as polyhydric alcohol, bisphenols, aliphatic amines, and aromatic amines to ring-opening addition reaction of alkylene oxide.

  Examples of the polyhydric alcohol used in the polyether polyol include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and neopentyl glycol. Cyclohexylene glycol, glycerin, trimethylolpropane and the like. Examples of bisphenols include bisphenol A, bisphenol F, bisphenol S, and the like. Examples of the aliphatic amine include monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine and the like. Aromatic amines include, for example, 2,4-diaminotoluene (TDA), 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylenediamine, diethyltolylenediamine, 1,2-xylenediamine 1,3-xylenediamine, 1,4-xylenediamine, 2,4'-diaminodiphenylmethane (MDA), 4,4'-diaminodiphenylmethane, naphthylene-1,5-diamine, 3,3'-dichloro-4 4,4'-diaminodiphenylmethane and the like. Said active hydrogen compound can be used individually or in mixture of 2 or more types.

  Examples of the alkylene oxide used in the polyether polyol include ethylene oxide, propylene oxide, and butylene oxide, and these can be used alone or in admixture of two or more.

  Examples of polyester polyols include compounds obtained by condensation reaction of polycarboxylic acids and polyhydric alcohols.

  Examples of the polycarboxylic acid used in the polyester polyol include malonic acid, maleic acid, succinic acid, adipic acid, tartaric acid, sebacic acid, oxalic acid, phthalic acid, terephthalic acid, azelaic acid, trimellitic acid, and the like. These can be used alone or in admixture of two or more.

  As the polyhydric alcohol used in the polyester polyol, the same polyhydric alcohol as used in the polyether polyol described above can be used.

  Examples of the polycarbonate polyol include polybutanediol carbonate, poly-3-methylpentanediol carbonate, polyhexanediol carbonate, polynonanediol carbonate, polybutanediol hexanediol carbonate, polypentanediol hexanediol carbonate, and the like.

  Examples of the polylactone polyol include polycaprolactone diol, polycaprolactone triol, and poly-3-methylvalerolactone diol.

  Examples of the polyolefin polyol include polybutadiene glycol, polyisoprene glycol or a hydride thereof.

  Silicone polyols are those in which hydroxyl groups are introduced into the polysiloxane main chain. Further, the introduced hydroxyl groups may be at both ends or one end of the polysiloxane main chain.

  In order to obtain a polyurethane composition having an appropriate tackiness and excellent peelability, which is the subject of the present invention, by adjusting the average functional group number and hydroxyl value of the polyol and the average functional group number of the isocyanate described later. Good.

  The average number of functional groups of the polyol is 2.5 to 4.0, preferably 2.5 to 3.0, from the viewpoint of increasing the crosslinking density to increase curability and imparting excellent peelability. .

  In addition to the above, the hydroxyl value of the polyol is 20 to 200 mgKOH / g, preferably 28 to 160 mgKOH / g, from the viewpoint of imparting appropriate tackiness and excellent peelability to the resulting polyurethane composition.

  Among these polyols, polyether polyols and polycarbonate polyols are preferably used from the viewpoint of durability of the resulting polyurethane composition, and polyether polyols are particularly preferably used from the viewpoint of workability during production and economy. It is done.

  The premix may contain an antifoaming agent, a catalyst, and an additive as needed in addition to the polyol.

  As will be described later, the antifoaming agent is used to prevent the appearance of poor appearance due to foam mixing when the obtained urethane composition is applied to the end of the support rod or applied to the substrate. Auxiliary agents added as necessary, for example, silicone-based antifoaming agents such as silicone oil (polydimethylsiloxane) and modified silicone oil; nonionic interfaces such as polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl ether Activating agents; Amide-based antifoaming agents; Silica silicone-based antifoaming agents; Metal soap-based antifoaming agents; Kerosene, mineral oils and the like can be mentioned, and these can be used alone or in admixture of two or more.

  The blending amount of the antifoaming agent varies depending on the type and the like, but is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the polyol.

  The catalyst is used as necessary in order to efficiently advance the reaction between the polyol and the isocyanate and accelerate the curing of the reaction product. For example, stannous octoate, dibutyltin diacetate, dibutyltin Organometallic compounds such as dilaurate, dibutyltin oxide, dioctyltin dilaurate, dioctyltin oxide, nickel acetylacetonate, octylzinc; triethylamine, triethylenediamine, 1,8-diazabicyclo (5,4,0) undecene-7, 1 , 5-diazabicyclo (4,3,0) nonene-5, N, N-dimethylbenzylamine, N-methylmorpholine, N, N-dimethylaminomethylphenol, tertiary amines such as 1,2-dimethylimidazole Compound; salt of the tertiary amine compound and an acid such as carboxylic acid or carbonic acid. Or it can be used in a mixture at Germany.

  Although the compounding quantity of a catalyst changes with the kinds, Preferably it is 0.001-5 weight part with respect to 100 weight part of said polyols, More preferably, it is 0.01-1 weight part.

  Examples of the additives include antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, anti-coloring agents, antibacterial fungicides, flame retardants, fillers, pigments, and the like. A mixture of seeds or more can be used. In addition, the said additive is added as needed in the range which does not impair the objective of this invention.

  The isocyanate is not particularly limited as long as it has two or more isocyanate groups at the terminal. For example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2, 2 '-Diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, 3,3'-dichloro-4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, phenylene diisocyanate, 1,5-naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate , Aromatic polyisocyanates such as hydrogenated xylylene diisocyanate and hydrogenated products thereof; 1,4-cyclohexane diisocyanate, isophorone diisocyanate, norbornane diisocyanate Alicyclic polyisocyanates such as tetramethylene diisocyanate, aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate; one kind of isocyanurate bond, carbodiimide bond, urethane bond, urea bond, burette bond, allophanate bond, etc. The above-mentioned modified polyisocyanate and the like can be mentioned, and these can be used alone or in admixture of two or more.

  Moreover, the average functional group number of isocyanate is 2-2.5 from a viewpoint of providing moderate adhesiveness to the polyurethane composition obtained.

  As a manufacturing method of a polyurethane composition, if it is a well-known manufacturing method, it will not specifically limit, For example, the premix which added the other component to the polyol or the polyol suitably, and mixed, and isocyanate are 20-50 degreeC. For example, a method of performing a defoaming treatment after mixing and stirring are included.

  In the reaction between the polyol and the isocyanate, from the viewpoint of increasing the crosslink density and increasing the curability of the reaction product, and from the viewpoint of imparting appropriate tackiness and excellent peelability to the resulting polyurethane composition, the blending ratio of both Is preferably prepared so as to have an isocyanate index of 70 to 120, more preferably 80 to 110.

  The polyurethane composition of the present invention is an OA device, semiconductor wafer, semiconductor package, optical member (lens, optical fiber, etc.), printed circuit board, film, touch panel, liquid crystal / PDP panel, hard disk related (hard disk member, etc.), communication device, medical device. It is preferably used as a constituent of the adhesive part of the foreign matter removing tool used when removing minute foreign matter attached to the surface of equipment or the like. Especially, it is used especially suitably as what comprises the adhesion part of the foreign material removal tool used when removing the micro foreign material adhering to the semiconductor wafer surface.

  As a specific use mode as a foreign matter removing tool, for example, at least one end of a support rod, the polyurethane composition after defoaming treatment obtained above is applied to a substantially spherical shape by a dip coating method or the like, The aspect which forms an adhesion part by making it harden | cure on the conditions of 20-160 degreeC and 1 minute-24 hours, and uses it as a stick form is mentioned. As the material of the support rod to be used, paper, wood, metal or plastic is preferably used.

  The adhesive part provided at the end of the support rod is formed in advance on the surface of the core part from the polyurethane composition obtained above after forming a core part made of lump-like cotton fibers, plastic beads, etc. You may comprise by apply | coating.

  As another use mode as a foreign matter removing tool, the adhesive composition is layered by applying the polyurethane composition obtained above on a substrate and curing it at 20 to 160 ° C. for 1 minute to 24 hours. The mode which forms in and uses as a sheet form is mentioned. Moreover, the aspect etc. which are used as a roll shape etc. are mentioned by using the base material made into the roll shape by making the other surface peelable. In addition, as a base material used for these, plastic films, such as polyolefin, polyester, a polycarbonate, a polyvinyl chloride, a cellophane, papers, etc. are mentioned, for example.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

(Examples 1-14 and Comparative Examples 1-20)
Polyols 1 to 17 shown in Table 1 were used as the polyol component, and isocyanates A and B shown in Table 2 were used as the isocyanate component. The combinations of both components are as shown in Table 3.

  In the polyol shown in Table 1, a nonionic surfactant (manufactured by San Nopco, trade name: SN deformer 260) as an antifoaming agent, and a tertiary amine catalyst (manufactured by San Apro, trade name: U-CAT) as a catalyst. SA1] and an organometallic catalyst [manufactured by Tokyo Fine Chemical Co., Ltd., trade name: L-101] were mixed and stirred at a blending ratio shown in Table 4 to prepare a premix.

Next, the isocyanate shown in Table 2 was blended with the obtained premix so that the isocyanate index was 105, mixed and stirred at 40 ° C., and then defoamed to obtain a mixture. Here, the state of the obtained mixture (color, compatibility between the polyol component and the isocyanate component) was evaluated. The evaluation criteria are as follows.
[Compatibility Evaluation Criteria]
○: Transparent, good compatibility △: Turquoise, slightly poor compatibility ×: Partial separation, poor compatibility

The mixture obtained above was applied to one end of an acrylic rod having a length of 5 cm and a diameter of 2 mm by a dip coating method so as to be approximately spherical with a diameter of about 2.5 mm, and then left at 80 ° C. for 1 hour. Then, an adhesive part was formed. It was allowed to stand at 25 ° C. for 24 hours, and the cured state of the mixture after the standing was evaluated. The evaluation criteria are as follows.
[Evaluation criteria for curability]
○: Cured △: Semi-cured ×: Uncured

  Evaluation of adhesiveness and peelability of the mixtures obtained in each Example and each Comparative Example was performed based on the following methods.

A. Adhesiveness The adhesiveness of the mixture was evaluated by pressing a stainless steel plate-shaped standard weight against the adhesive part and measuring the weight that can be lifted for 5 seconds or more. Here, the contact area of the adhesive portion with respect to the standard weight is about 0.80 mm ² , and the mass of the standard weight used for the evaluation is 0.01 g, 0.03 g, 0.05 g, 0.08 g, 0.10 g. 0.30 g, 0.50 g, 0.80 g and 1.00 g. It should be noted that in the case of removing minute foreign substances adhering to the OA equipment, semiconductor wafer surface, etc., it is sufficient if a standard weight of 0.01 g or more can be lifted in this evaluation method.

B. Peelability Lightly press the adhesive part against the surface of the semiconductor wafer (the contact area of the adhesive part with respect to the semiconductor wafer surface is about 0.80 mm ² ) and peel it off several times. The surface of the semiconductor wafer before and after the operation The state was observed at a magnification of 150 times using a digital microscope [manufactured by Keyence Corporation, model number: VH6300]. Then, from the observation photographs before and after the operation, the peelability of the mixture was evaluated by examining the increase / decrease in the number of foreign substances present on the surface of the semiconductor wafer. That is, after the operation, the number of foreign substances existing on the surface of the semiconductor wafer is reduced, or when the number is the same, no adhesive residue is generated, and it can be said that the peelability of the reactant is excellent.
[Evaluation criteria for peelability]
○: The number of foreign matters decreases or is the same, and has excellent peelability. X: Adhesive residue is generated, the number of foreign matters increases, and the peelability is poor.

  Table 5 shows the evaluation results on the tackiness and peelability of the mixtures obtained in Examples 1 to 6, Reference Examples 1 to 8, and Comparative Examples 1 to 20, together with the compatibility and curability evaluation results.

  As shown in Table 5, the compatibility between the polyol and the isocyanate was slightly worse in Comparative Examples 11 and 19, but was good in all others. From this, it is considered that the polyurethane composition was produced in a good mixed state in each of the examples and the comparative examples.

  Moreover, in each Example, Comparative Examples 1-4, and Comparative Examples 9-15, favorable sclerosis | hardenability was shown. On the other hand, in Comparative Examples 5 to 6 and Comparative Examples 16 to 18, curing did not proceed completely, and curing did not occur in Comparative Examples 7 to 8 and Comparative Examples 19 to 20.

  From the results shown in Table 5, the polyurethane composition obtained in each example has the necessary adhesiveness when removing fine foreign substances adhering to the OA equipment, semiconductor wafer surface, etc., and excellent peelability. It can be seen that In addition, when Examples 1-6 were compared with Reference Examples 5-8, the direction of Examples 1-6 using the polyol whose part of a terminal functional group is a primary hydroxyl group is more adhesive. I know that there is.

  On the other hand, the polyurethane compositions obtained in Comparative Examples 7 to 8 and Comparative Examples 19 to 20 could not be evaluated for tackiness because curing did not occur as described above. Moreover, it does not have excellent peelability.

  The polyurethane compositions obtained in Comparative Examples 3 to 4, Comparative Examples 9 to 10 and Comparative Examples 13 to 14 become glassy having no tackiness and can be evaluated for tackiness and peelability. There wasn't.

  In addition, the polyurethane compositions obtained in Comparative Examples 1-2, Comparative Examples 5-6, Comparative Examples 11-12, and Comparative Examples 15-18 remove tiny foreign substances attached to OA equipment, semiconductor wafer surfaces, and the like. Although it has the necessary adhesiveness when performing, etc., it does not have excellent peelability.

  Specifically, the operation in the case where the adhesive part made of the polyurethane composition obtained in Example 3, Comparative Example 5 and Comparative Example 15 was lightly pressed against the surface of the semiconductor wafer and then peeled off several times. Observation photographs of the front and rear semiconductor wafer surfaces are shown in FIGS.

  From the observation photograph in FIG. 1, it can be seen that in Example 3, the number of foreign matters on the surface of the semiconductor wafer decreased after the operation compared with before the operation, and the peelability was excellent. On the other hand, it can be seen from the observation photograph of FIG. 3 that in Comparative Example 15, the number of foreign matters on the surface of the semiconductor wafer is increased after the operation compared to before the operation, and a slight amount of glue remains. In addition, it can be seen from the observation photograph in FIG. 2 that in Comparative Example 5, the number of foreign matters on the surface of the semiconductor wafer has increased remarkably after the operation, and a large number of adhesive residues have occurred. This is because the polyurethane composition of Comparative Example 5, as shown in Table 5, was not particularly good in curability, so it seems that the peelability is particularly inferior.

Claims (5)

  A polyether polyol having a hydroxyl value of 20 to 200 mg KOH / g, an average functional group number of 2.5 to 4.0, and an EO content of 8 to 20%, and an average functional group number of 2.0 to 2. A pressure-sensitive adhesive for removing fine foreign substances, comprising a polyurethane composition obtained by cross-linking reaction with an aromatic polyisocyanate which is No. 5.   A fine foreign matter removing tool, wherein an adhesive portion made of the adhesive according to claim 1 is provided on at least one end of a support rod.   A fine foreign matter removing tool, wherein a pressure-sensitive adhesive portion made of the pressure-sensitive adhesive according to claim 1 is provided in a layer form on a substrate.   A fine foreign matter removing tool comprising the pressure-sensitive adhesive according to claim 1.   On the surface of OA equipment, semiconductor wafer, semiconductor package, optical member (lens, optical fiber, etc.), printed circuit board, film, touch panel, liquid crystal / PDP panel, hard disk related (hard disk member, etc.), communication equipment, or medical equipment. A method for removing fine foreign matter, comprising performing the operation of pressing and peeling the pressure-sensitive adhesive according to 1 several times.

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