JP6221630B2 - Liquid gasket for small portable electronic devices - Google Patents

Description

The present invention relates to an in-situ molded liquid gasket for small portable electronic devices containing an oxyalkylene polymer having a hydrolyzable group bonded to a silicon atom and having a silicon-containing group that can be crosslinked by forming a siloxane bond. . Hereinafter, a silicon-containing group that has a hydrolyzable group bonded to a silicon atom and can be cross-linked by forming a siloxane bond is also referred to as a cross-linkable silicon group.

  Small portable electronic devices such as mobile phones, smartphones, tablets, mobile PCs, MP3 players, digital video recorders, and digital cameras protect internal electronic circuits, memory, CPU, and battery parts from external dust and moisture. For this reason, these parts are usually contained in two housing members such as a main body and a lid, and the two housing members are sealed by a sealing means such as an O-ring provided around the housing member. In addition, the liquid crystal display member, the operation member such as a button, the battery, and the like may be individually sealed by a sealing means provided around the component. As sealing means, solid gaskets, liquid gaskets, adhesives, double-sided adhesive products such as double-sided tape, and the like are used.

  In the manufacturing process of a small portable electronic device, when a defective product occurs, the defective portion is replaced and repaired. Such reworking is called reworking, and when reworking is necessary after sealing the housing member, the sealing means must be removed.

  A solid gasket such as an O-ring is an elastic sealing material molded in advance, and is tightened and sealed with a screw or the like. In this case, the gasket can be easily removed by removing a screw or the like. Therefore, rework work is easy when a solid gasket is used. However, since the solid gasket is manufactured using a mold, it is expensive and requires a fastening means such as a screw.

  A liquid gasket (on-site molded gasket) is a gasket that is formed by applying an uncured liquid material to the portion to be sealed in the shape of the gasket and curing it. This is called FIPG (Formed In Place Gasket) and CIPG (Cured) In Place Gasket). In these gaskets, no mold is required.

  FIPG is a method in which an uncured liquid material is applied to a portion to be sealed, a housing member is sandwiched, and then cured. The sealing performance is excellent because it is a seal by adhesion, but usually the cured product is strongly adhered to the substrate, and the removal of the gasket is not easy. For this reason, FIPG is not a suitable method for rework work.

  CIPG is a method in which an uncured liquid material is applied to a portion to be sealed and cured before sandwiching the housing member. The other housing member is clamped by a fastening means such as a screw after curing, and the rework work is easy, but a fastening means such as a screw is required.

  Adhesion with an adhesive is the same as FIPG, and sealing performance is excellent because it is a seal by adhesion, but usually the cured product is strongly adhered to the base material, and it is not easy to remove the gasket. For this reason, bonding with an adhesive is not a suitable method for rework work.

  In addition, although the housing member is relatively easy to remove with a double-sided adhesive product such as a double-sided adhesive tape, it is not easy for the double-sided tape to remain only on one housing member during removal. In addition, there is a problem that the work of mounting the double-sided tape or the like on the housing member is complicated.

  Among these gaskets, FIPG has the best sealing performance but is not suitable for rework. However, if there is a FIPG that is excellent in reworkability, it is considered very useful. That is, the housing member can be removed with a small force, and the gasket does not break at the time of removal and remains on one housing member. After reworking, the gasket can be used as it is to reconnect the housing member. The FIPG is capable of maintaining sealing performance such as waterproof performance.

  Patent Document 1 discloses a waterproof sealing method for small portable electronic devices using a curable liquid composition containing an oxyalkylene polymer having a crosslinkable silicon group (Patent Document 1, Example 1). The oxyalkylene polymer having a crosslinkable silicon group is liquid at room temperature, and crosslinks at room temperature by the action of moisture such as moisture in the air to produce a cured product such as rubber. For this reason, Patent Document 1 discloses that a curable liquid composition containing an oxyalkylene polymer having a crosslinkable silicon group can be suitably used as a FIPG used in small portable electronic devices. Further, Example 1 of Patent Document 1 discloses that the peeling mode between the cured gasket and the housing member is interface peeling. This is because it is possible to remove the housing member with a small force, and it is considered that it is excellent in reworkability because it remains in one housing member without rupturing at the time of removal. However, it is difficult to maintain the sealing performance such as the initial waterproof performance even after recombination. This is because the cured gasket does not have adhesiveness to a base material such as a housing member so that the peeled cured adhesive does not have adhesiveness.

JP 2011-086817 A WO2013-128752

  The problem to be solved by the present invention is a FIPG for a small portable electronic device using a curable liquid composition containing an oxyalkylene polymer having a crosslinkable silicon group, and a housing bonded using the FIPG In the member, the housing member can be removed with a small force. At the time of removal, the gasket does not break and remains in one housing member. After reworking, the gasket can be used as it is, and the housing member can be reconnected. It is to provide a FIPG that can maintain sealing performance such as waterproof performance.

  The present inventors use a curable composition containing an oxyalkylene polymer having a crosslinkable silicon group and a tackifying resin disclosed in Patent Document 2, and the above-mentioned FIPG using a relatively small amount of an adhesion-imparting agent. I found that the problem was solved. That is, the present invention is the following on-site molded liquid gasket for small portable electronic devices.

The on-site molded liquid gasket for small portable electronic devices of the present invention is (A) an oxyalkylene polymer having a hydrolyzable group bonded to a silicon atom and a silicon-containing group that can be crosslinked by forming a siloxane bond. 100 parts by mass,
(B) An on-site mold for a small portable electronic device containing 50 to 250 parts by mass of a tackifying resin and (C) 0.01 to 0.8 parts by mass of an aminosilane compound , the on-site mold The liquid gasket is a FIPG gasket, that is, a gasket obtained by applying an uncured liquid material to a portion to be sealed, sandwiching a housing member, and then curing the liquid gasket. It is a gasket .

  The in-situ molded liquid gasket for small portable electronic devices of the present invention is suitably used for small portable electronic devices.

  The method for reworking a small portable electronic device according to the present invention includes (a) forming a siloxane bond having (A) a hydrolyzable group bonded to a silicon atom as an on-site molded liquid gasket for the small portable electronic device. 100 parts by mass of an oxyalkylene polymer having a silicon-containing group that can be cross-linked, (B) 50 to 250 parts by mass of a tackifying resin, and (C) 0.01 to 0.8 parts by mass of an aminosilane compound (B) a step of preparing an in-situ molded liquid gasket, and (b) applying the liquid gasket to a portion to be sealed of one housing member of a small portable electronic device in an uncured state and sandwiching the other housing member, C) A process of curing an uncured liquid gasket, (d) Removing a housing member of a small portable electronic device that requires rework after curing, and replacing internal components Degree, and characterized by having a (e) the steps of a process for re-sealing the housing member using the cured liquid gasket directly as a gasket.

  The on-site molded liquid gasket for a small portable electronic device according to the present invention is a housing member joined by using this liquid gasket, and the housing member can be removed with a small force. It remains on the member, and after reworking, the gasket can be used as it is, so that the housing member can be recombined, and the sealing performance such as the initial waterproof performance can be maintained even after recombination.

  In the liquid gasket of the present invention, the crosslinkable silicon group in the oxyalkylene polymer of the component (A) has a hydrolyzable group bonded to a silicon atom, and is a group that can be crosslinked by forming a siloxane bond. As a representative example, the formula (1):

（式中、Ｒ^１は、炭素数１〜２０のアルキル基、炭素数３〜２０のシクロアルキル基、炭素数６〜２０のアリール基、炭素数７〜２０のアラルキル基またはＲ^２ _３ＳｉＯ−で示されるトリオルガノシロキシ基（Ｒ^２は、炭素数１〜２０のアルキル基、炭素数３〜２０のシクロアルキル基、炭素数６〜２０のアリール基、炭素数７〜２０のアラルキル基）を示し、Ｒ^１が２個以上存在するとき、それらは同一であってもよく、異なっていてもよい。Ｘは加水分解性基を示し、Ｘが２個以上存在するとき、それらは同一であってもよく、異なっていてもよい。ａは０、１、２または３を、ｂは０、１または２を、それぞれ示す。またｎ個の式（２）：

(In the formula, R ¹ represents an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or R ² ₃ SiO— (Wherein R ² is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms). When two or more R ¹ are present, they may be the same or different, X represents a hydrolyzable group, and when two or more X are present, they are the same. A may be 0, 1, 2 or 3, b may be 0, 1 or 2, and n formulas (2):

におけるｂは同一である必要はない。ｎは０〜１９の整数を示す。但し、ａ＋（ｂの和）≧１を満足するものとする。）で表わされる基があげられる。

B in need not be the same. n shows the integer of 0-19. However, a + (sum of b) ≧ 1 is satisfied. ).

The hydrolyzable group can be bonded to one silicon atom in the range of 1 to 3, and a + (sum of b) is preferably in the range of 1 to 5. When two or more hydrolyzable groups or hydroxyl groups are bonded to the crosslinkable silicon group, they may be the same or different.
The number of silicon atoms forming the crosslinkable silicon group may be one or two or more, but in the case of silicon atoms linked by a siloxane bond or the like, there may be about 20 silicon atoms.
Formula (3):

A crosslinkable silicon group represented by the formula (wherein R ¹ , X and a are the same as described above) is preferable from the viewpoint of easy availability. In the crosslinkable silicon group of the formula (3), a is preferably 2 or 3. When a is 3, the curing rate is higher than when a is 2.

Specific examples of R ¹ include an alkyl group such as a methyl group and an ethyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, an aralkyl group such as a benzyl group, and R ² ₃ SiO—. And triorganosiloxy group. Of these, a methyl group is preferred.

  It does not specifically limit as a hydrolysable group shown by said X, What is necessary is just a conventionally well-known hydrolysable group. Specific examples include a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, and an alkenyloxy group. Among these, a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group, and an alkenyloxy group are preferable, and an alkoxy group, an amide group, and an aminooxy group are more preferable. An alkoxy group is particularly preferred from the viewpoint of mild hydrolysis and easy handling. Among the alkoxy groups, those having a smaller number of carbon atoms have higher reactivity, and the reactivity increases as the number of carbon atoms increases in the order of methoxy group> ethoxy group> propoxy group. Although it can be selected according to the purpose and application, a methoxy group or an ethoxy group is usually used. In the case of the crosslinkable silicon group represented by the formula (3), a is preferably 2 or more in consideration of curability.

Specific examples of the crosslinkable silicon group include a general formula such as a trimethoxysilyl group and a triethoxysilyl group, a trialkoxysilyl group represented by —Si (OR) ₃ , a methyldimethoxysilyl group, and a methyldiethoxy group. And a general formula such as a silyl group, and a dialkoxysilyl group represented by -SiR ¹ (OR) ₂ . Here, R ¹ is the same as described above, and R is an alkyl group such as a methyl group or an ethyl group.

  Further, the crosslinkable silicon group may be used alone or in combination of two or more. The crosslinkable silicon group can be present in either the main chain or the side chain. It is preferable that a crosslinkable silicon group is present at the end of the molecular chain from the viewpoint of excellent cured product properties such as tensile properties of the cured product.

  It is preferable that at least one, preferably 1.1 to 5, crosslinkable silicon groups are present in one molecule of the polymer. When the number of crosslinkable silicon groups contained in the molecule is less than one, the curability is insufficient, and when the number is too large, the network structure becomes too dense, and good mechanical properties are not exhibited. In particular, in the case of producing a curable composition of a so-called non-plastic compound that does not contain a low molecular weight plasticizer having a molecular weight of 800 or less, such as a phthalate ester plasticizer, and a molecular weight of 1000 or less, the crosslinkable silicon group is It is preferable that 1.1 to 1.5, more preferably 1.1 to 1.3 are present on average in one molecule of the polymer. In the case of a curable composition containing no plastic, it is preferable to use a linear polymer.

  The main chain skeleton of the oxyalkylene polymer having a crosslinkable silicon group is essentially a polymer having a repeating unit represented by the formula (4).

（式中、Ｒ^３は２価の有機基）

(Wherein R ³ is a divalent organic group)

R ³ in Formula (4) is preferably a linear or branched alkylene group having 1 to 14 carbon atoms, and more preferably 2 to 4 carbon atoms. Specific examples of the repeating unit represented by the formula (4) include, for example,

Etc. The main chain skeleton of the polyoxyalkylene polymer may be composed of only one type of repeating unit, or may be composed of two or more types of repeating units.

  Specific examples of the polyoxyalkylene polymer include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, polyoxypropylene-polyoxybutylene copolymer. And polyoxyalkylene polymers such as In particular, it is preferably made of a polymer mainly composed of oxypropylene.

  The molecular weight of the polyoxyalkylene polymer is preferably larger when the tensile modulus, which is the tensile property of the cured product, is reduced and the elongation at break is increased. In the present invention, the lower limit of the number average molecular weight is preferably 5,000, and more preferably 10,000. Further, the upper limit of the number average molecular weight is preferably 50,000, and more preferably 30,000. In addition, the number average molecular weight as used in the field of this invention means the polystyrene conversion molecular weight by gel permeation chromatography. When the number average molecular weight is less than 5,000, the tensile modulus and elongation at break may not be sufficient. When the number average molecular weight exceeds 50,000, the viscosity of the composition may increase and workability may decrease.

  The polyoxyalkylene polymer may be linear or branched, but is preferably a linear polymer because the tensile modulus of the cured product can be reduced and the elongation at break can be increased. The molecular weight distribution of the polyoxyalkylene polymer having a crosslinkable silicon group is preferably 2 or less, particularly 1.6 or less.

  As a method for synthesizing a polyoxyalkylene polymer, for example, a polymerization method using an alkali catalyst such as KOH, for example, JP-A Nos. 61-197631, 61-215622, 61-215623, and 61-215623 can be used. Polymerization methods using an organoaluminum-porphyrin complex catalyst obtained by reacting an organoaluminum compound with porphyrin as shown, for example, double metal cyanide complexes shown in JP-B-46-27250 and JP-B-59-15336 Examples of the polymerization method using a catalyst include, but are not limited to, a polymerization method. According to the polymerization method using an organoaluminum-porphyrin complex catalyst or the polymerization method using a double metal cyanide complex catalyst, the number average molecular weight is 6,000 or more, and the Mw / Mn is 1.6 or less. Coalescence can be obtained.

  The main chain skeleton of the polyoxyalkylenes may contain other components such as a urethane bond component. Examples of the urethane bond component include aromatic polyisocyanates such as toluene (tolylene) diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate; aliphatic polyisocyanates such as isophorone diisocyanate and hexamethylene diisocyanate and polyoxyalkylenes having a hydroxyl group; What can be obtained from this reaction can be mentioned.

  The introduction of a crosslinkable silicon group into a polyoxyalkylene polymer can be performed on a polyoxyalkylene polymer having a functional group such as an unsaturated group, a hydroxyl group, an epoxy group or an isocyanate group in the molecule. The reaction can be carried out by reacting a compound having a reactive functional group and a crosslinkable silicon group. Hereinafter, a method for introducing a crosslinkable silicon group, in which a polymer having a functional group is reacted with a compound having a functional group reactive to the functional group and a crosslinkable silicon group is referred to as a polymer reaction method. The polyoxyalkylene polymer easily introduces a functional group such as a hydroxyl group at the molecular chain terminal, and therefore easily introduces a crosslinkable silicon group at the terminal.

  As a specific example of the polymer reaction method, a hydrosilane or mercapto compound is produced by reacting an unsaturated group-containing oxyalkylene polymer with a hydrosilane having a crosslinkable silicon group or a mercapto compound having a crosslinkable silicon group to form a crosslinkable silicon group. The method of obtaining the oxyalkylene type polymer which has can be mention | raise | lifted. The unsaturated group-containing oxyalkylene polymer has an active group and an unsaturated group which are reactive to the functional group, such as an unsaturated halogen compound, in the oxyalkylene polymer having a functional group such as a hydroxyl group. By reacting an organic compound, an oxyalkylene polymer containing an unsaturated group can be obtained.

  Other specific examples of the polymer reaction method include a method of reacting an oxyalkylene polymer having a hydroxyl group at a terminal with a compound having an isocyanate group and a crosslinkable silicon group, or an oxyalkylene polymer having an isocyanate group at a terminal. And a method of reacting a compound having an active hydrogen group such as a hydroxyl group or an amino group and a crosslinkable silicon group. When an isocyanate compound is used, an oxyalkylene polymer having a crosslinkable silicon group can be easily obtained. The polymer reaction method can be applied to polymers other than oxyalkylene polymers.

  Specific examples of the oxyalkylene polymer having a crosslinkable silicon group include JP-B Nos. 45-36319 and 46-12154, JP-A Nos. 50-156599, 54-6096, and 55-13767. No. 57-164123, Japanese Patent Publication No. 3-2450, Japanese Patent Application Laid-Open No. 2005-213446, No. 2005-306891, International Publication No. WO 2007-040143, US Pat. Nos. 3,632,557, 4,345,053, The ones proposed in the publications such as 4,960,844 can be mentioned.

  The oxyalkylene polymer having a crosslinkable silicon group can be used in combination with another polymer having a crosslinkable silicon group. The main chain skeleton of the other polymer is not particularly limited, and those having various main chain skeletons can be used. For example, ethylene-propylene copolymer, saturated hydrocarbon polymer such as polyisobutylene, copolymer of isobutylene and isoprene, polychloroprene, polyisoprene, isoprene or butadiene and acrylonitrile and / or styrene. Polymers, polybutadiene, isoprene or copolymers of butadiene and acrylonitrile, and / or styrene, etc., and hydrocarbon polymers such as hydrogenated polyolefin polymers obtained by hydrogenating these polyolefin polymers; adipine Polyester polymers such as condensation polymers of polybasic acids such as acid, terephthalic acid and succinic acid and polyhydric alcohols such as bisphenol A, ethylene glycol and neopentyl glycol, and ring-opening polymers of lactones; ε-caprolactam By ring-opening polymerization of Ron 6, Nylon 6 · 6 by condensation polymerization of hexamethylene diamine and adipic acid, Nylon 6 · 10 by condensation polymerization of hexamethylene diamine and sebacic acid, Nylon 11 by condensation polymerization of ε-aminoundecanoic acid, ε-aminolaurolactam Nylon 12 by ring-opening polymerization of the above, polyamide-based polymer such as copolymer nylon having two or more components among the above nylons; polyacrylic obtained by ion polymerization or radical polymerization of monomers such as ethyl acrylate and butyl acrylate Acrylic acid ester-based polymers such as acrylic acid esters, ethyl acrylate, butyl acrylate, etc., and acrylic acid ester copolymers of vinyl acetate, acrylonitrile, methyl methacrylate, styrene, etc .; polysulfide-based polymers; Polycarbonate-based polymers produced by condensation polymerization from a carbonyl chloride with Lumpur A, diallyl phthalate polymers, and the like.

  As a polymer used in combination with a polyoxyalkylene polymer, a (meth) acrylic acid alkyl ester polymer has excellent mechanical strength of a cured product of the combined product, and excellent heat resistance and adhesion to a substrate. Therefore, it is suitable for the present invention. When a mixture of an oxyalkylene polymer having a crosslinkable silicon group and a (meth) acrylic acid ester polymer having a crosslinkable silicon group is used, the (meth) acrylic acid is used with respect to 100 parts by mass of the oxyalkylene polymer. It is preferable to use 5-200 mass parts of ester polymers, and it is more preferable to use 5-50 mass parts.

  The (meth) acrylic acid alkyl ester polymer having a crosslinkable silicon group is essentially a polymer having a repeating unit represented by the formula (5).

（式中、Ｒ^４は水素原子またはメチル基、Ｒ^５はアルキル基を示す）

(Wherein R ⁴ represents a hydrogen atom or a methyl group, and R ⁵ represents an alkyl group)

R ⁵ in Formula (5) is an alkyl group, and an alkyl group having 1 to 30 carbon atoms is preferable. R ⁵ may be linear or branched. Moreover, the substituted alkyl group which has a halogen atom, a phenyl group, etc. may be sufficient. Examples of R ⁵ include methyl, ethyl, propyl, n-butyl, t-butyl, 2-ethylhexyl, lauryl, tridecyl, cetyl, stearyl, behenyl, glycidyl, etc. Examples thereof include an amino group-substituted alkyl group such as an epoxy group-substituted alkyl group and a diethylaminoethyl group.

  The molecular chain of the (meth) acrylic acid alkyl ester polymer consists essentially of the monomer unit of the formula (5), and the term “essentially” as used herein means that of the formula (5) present in the polymer. It means that the total of monomer units exceeds 50% by weight. The total of the monomer units of the formula (5) is preferably 70% by weight or more.

  Examples of monomer units other than formula (5) include (meth) acrylic acid such as acrylic acid and methacrylic acid; amide groups such as acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, and aminoethyl Monomers containing amino groups such as vinyl ether; and other monomer units derived from acrylonitrile, styrene, α-methylstyrene, alkyl vinyl ether, vinyl chloride, vinyl acetate, vinyl propionate, ethylene and the like.

  As described above, the (meth) acrylic acid alkyl ester polymer having a crosslinkable silicon group may be used in combination with an oxyalkylene polymer. In this case, in terms of high compatibility with the oxyalkylene polymer having a crosslinkable silicon group, the molecular chain having a crosslinkable silicon group has the following formula (6):

（式中、Ｒ^４は前記に同じ、Ｒ^６は炭素数１〜５のアルキル基を示す）で表される（メタ）アクリル酸エステル単量体単位と、下記式（７）：

(Wherein R ⁴ is the same as above, R ⁶ is an alkyl group having 1 to 5 carbon atoms) and a (meth) acrylate monomer unit represented by the following formula (7):

（式中、Ｒ^４は前記に同じ、Ｒ^７は炭素数６以上のアルキル基を示す）で表される（メタ）アクリル酸エステル単量体単位からなる共重合体が好ましい。

A copolymer composed of a (meth) acrylic acid ester monomer unit represented by the formula (wherein R ⁴ is the same as above, and R ⁷ is an alkyl group having 6 or more carbon atoms) is preferred.

As R < ⁶ > of the said Formula (6), C1-C5, such as a methyl group, an ethyl group, a propyl group, n-butyl group, t-butyl group, etc., Preferably it is 1-4, More preferably, it is 1-2. Of the alkyl group. Incidentally, R ⁶ may be a kind, or may be a mixture of two or more.

R ^{7 in the} above formula (7) is, for example, 2-ethylhexyl group, lauryl group, tridecyl group, cetyl group, stearyl group, behenyl group and the like having 6 or more carbon atoms, usually 7-30, preferably 8-20. Long chain alkyl groups. R ⁷ may be a single type or a mixture of two or more types. Moreover, the weight ratio of the monomer unit of the formula (6) and the monomer unit of the formula (7) is preferably 95: 5 to 40:60, and more preferably 90:10 to 60:40.

  The (meth) acrylic acid alkyl ester polymer having a crosslinkable silicon group can usually be obtained by radical copolymerization of a (meth) acrylic acid alkyl ester and a (meth) acrylic acid alkyl ester having a crosslinkable silicon group. . Further, when an initiator having a crosslinkable silicon group or a chain transfer agent having a crosslinkable silicon group is used, the crosslinkable silicon group can be introduced into the molecular chain terminal.

  JP 2001-040037 A, JP 2003-048923 A and JP 2003-048924 A have a crosslinkable silicon group (meth) obtained by using a mercaptan having a crosslinkable silicon group and a metallocene compound. Acrylic acid alkyl ester polymers are described. Moreover, the synthesis example of Unexamined-Japanese-Patent No. 2005-026881 describes the (meth) acrylic-acid alkylester type polymer which has a crosslinkable silicon group by high temperature continuous polymerization.

  As disclosed in JP-A-2000-086999, a (meth) acrylic acid alkyl ester-based polymer having a crosslinkable silicon group, in which a crosslinkable silicon group is introduced at a high ratio at the molecular chain terminal, Are known. Since such a polymer is produced by living radical polymerization, a crosslinkable silicon group can be introduced into the molecular chain terminal at a high rate. In the present invention, a (meth) acrylic acid alkyl ester polymer as described above can be used.

  Specific examples of a (meth) acrylic acid ester-based polymer having a crosslinkable silicon group and a mixture of this polymer and an oxyalkylene polymer having a crosslinkable silicon group are disclosed in JP-A Nos. 59-122541 and 63-112642. And in each publication such as JP-A-6-172631. JP-A-59-78223, JP-A-59-168014, JP-A-60-228516, JP-A-60-228517, etc. disclose oxyalkylene polymers having a crosslinkable silicon group. (Meth) acrylic acid ester-based monomer is polymerized in the presence of a mixture of an oxyalkylene polymer having a crosslinkable silicon group and a (meth) acrylic acid alkyl ester polymer having a crosslinkable silicon group. The method of obtaining is described.

  A saturated hydrocarbon polymer can be used as a polymer having a crosslinkable silicon group other than the oxyalkylene polymer. The saturated hydrocarbon polymer is a polymer that does not substantially contain a carbon-carbon unsaturated bond other than an aromatic ring, and the polymer constituting the skeleton is (1) ethylene, propylene, 1-butene, isobutylene, or the like. After polymerizing such an olefin compound having 2 to 6 carbon atoms as a main monomer, or (2) homopolymerizing a diene compound such as butadiene or isoprene, or copolymerizing with an olefin compound However, isobutylene-based polymers and hydrogenated polybutadiene-based polymers can be easily introduced with functional groups at the terminals, the molecular weight can be easily controlled, and the number of terminal functional groups can be adjusted. An isobutylene polymer is particularly preferable because it can be increased.

  Those whose main chain skeleton is a saturated hydrocarbon polymer have characteristics of excellent heat resistance, weather resistance, durability, and moisture barrier properties. In the isobutylene-based polymer, all of the monomer units may be formed from isobutylene units, or may be a copolymer with other monomers, but the repeating unit derived from isobutylene is 50 from the viewpoint of rubber properties. Those containing at least mass% are preferred, those containing at least 80 mass% are more preferred, and those containing from 90 to 99 mass% are particularly preferred.

  As a method for synthesizing a saturated hydrocarbon polymer, various polymerization methods have been reported so far, but in particular, many so-called living polymerizations have been developed in recent years. In the case of saturated hydrocarbon polymers, particularly isobutylene polymers, the inifer polymerization found by Kennedy et al. (JP Kennedy et al., J. Polymer Sci., Polymer Chem. Ed. 1997, 15, 2843) It is known that it can be easily produced by using it, it can be polymerized with a molecular weight of about 500 to 100,000 with a molecular weight distribution of 1.5 or less, and various functional groups can be introduced at the molecular ends.

  Examples of the method for producing a saturated hydrocarbon polymer having a crosslinkable silicon group include, for example, Mochikoku 4-69659, JP-B-7-108928, JP-A-63-254149, JP-A-64-22904, Although described in JP-A-1-197509, JP-A-2539445, JP-A-2873395, JP-A-7-53882 and the like, it is not particularly limited thereto. The above saturated hydrocarbon polymer having a crosslinkable silicon group may be used alone or in combination of two or more.

  The liquid gasket of the present invention contains a tackifying resin as the component (B). By adding a tackifying resin, the liquid gasket of the present invention has tackiness after curing, and even when it is reattached, strong adhesiveness to a substrate such as a housing member can be obtained due to tackiness.

  Examples of tackifying resins include: styrene-based (co) polymers; coumarone-indene resins, coumarone resins such as coumarone resins mixed with naphthene resins, phenol resins, rosins, etc .; pt-butylphenol-acetylene resins; Phenolic resins such as phenol formaldehyde resins, xylene-phenol resins, xylene resins having a low degree of polymerization and a low softening point of about 60 to 100 ° C. Terpene resins; synthetic polyterpene resins, aromatic hydrocarbon resins, aliphatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, hydrogenated hydrocarbon resins and other petroleum hydrocarbon resins; rosin and rosin pentaerythritol Esters, rosin glycerol esters, hydrogenated rosin, highly water Added wood resin, methyl ester of hydrogenated rosin, triethylene glycol ester of hydrogenated rosin, pentaerythritol ester of hydrogenated rosin, polymerized rosin, glycerol ester of polymerized rosin, resin acid zinc, hardened rosin and other rosin derivatives Low molecular weight polystyrene, other special preparations and the like, but are not limited thereto. Among these, a styrene polymer and / or a styrene copolymer is particularly preferable in that adhesion to a hardly adhesive material can be imparted. These tackifier resins may be used alone or in combination of two or more.

  As the styrene-based (co) polymer, conventionally known ones can be widely used and are not particularly limited. (Co) polymer obtained by (co) polymerizing 1 or more types of monomers is mentioned. As the styrenic polymer, for example, FTR-8100 and FTR-8120 (both product names, manufactured by Mitsui Chemicals, Inc.) can be used. In addition, as the styrene copolymer, a copolymer obtained by copolymerizing one or more styrene monomers and one or more other monomers copolymerizable therewith may be used. Is possible. The copolymerizable monomer is not particularly limited, and examples thereof include α-olefins having 2 to 12 carbon atoms such as 1-heptene, ethyl-1-butene, and methyl-1-nonene; -Unsaturated compounds such as non-conjugated dienes such as pentadiene and dicyclopentadiene. As the styrene copolymer, for example, FTR-6100, FTR-6125, and FTR-7125 (all of which are product names, manufactured by Mitsui Chemicals, Inc.) can be used. The above styrenic (co) polymers may be used alone or in combination of two or more.

  (B) As for the mixture ratio of a component, it is preferable to use 50-250 mass parts with respect to 100 mass parts of (A) component, It is more preferable to use 100-250 mass parts, It is further more preferable to use 130-200 mass parts. preferable. If it is less than 50 parts by mass, a sufficient adhesive force cannot be obtained, which is not preferable. When it exceeds 250 parts by mass, when applying the liquid gasket of the present invention, there is a possibility that fluidity is lowered and workability is deteriorated.

  The liquid gasket of the present invention contains an aminosilane compound as the component (C). By adding the aminosilane compound, the liquid gasket of the present invention exhibits strong adhesiveness together with the tackifying resin. Aminosilane compounds are known as adhesion-imparting agents, and in addition to aminosilanes, epoxy silanes, mercapto group silanes, (meth) acryloyl group-containing silanes, isocyanate silanes, chlorine atom-containing silanes, and the like are known. However, it is necessary to use an aminosilane compound. If aminosilane is not used, sufficient adhesive strength cannot be obtained when the cured liquid gasket of the present invention is once peeled and re-adhered.

  Examples of aminosilane compounds include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (Β-aminoethyl) -γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, 1,3-diaminoisopropyltrimethoxysilane, aminomethyltrimethoxysilane, aminomethyl Examples include methyldimethoxysilane.

  The usage-amount of an aminosilane compound needs to be 0.01-0.8 mass part with respect to 100 mass parts of oxyalkylene type polymers which have a crosslinkable silicon group of (A) component. This range is a small amount compared with the aminosilane compound usually used. When the aminosilane compound is used in an amount of 1.0 part by mass or more, when the cured liquid gasket of the present invention is first peeled off, the housing member cannot be removed with a small force, and the gasket is broken at the time of removal and remains in one housing member. There may not be. Thus, it is important that the amount of aminosilane compound used is 0.01 to 0.8 parts by mass or less, which is a smaller amount than usual.

  In addition to the aminosilane compound, another adhesiveness imparting agent such as epoxysilane may be added to the liquid gasket of the present invention. Examples of adhesion-imparting agents other than aminosilane compounds include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4-epoxy Cyclohexyl) epoxy group-containing silanes such as ethyltrimethoxysilane; mercapto group-containing silanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropylmethyldimethoxysilane; γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxy (Meth) acryloyl group-containing silanes such as propylmethyldimethoxysilane; chlorine atom-containing silanes such as γ-chloropropyltrimethoxysilane; γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyl Examples include isocyanate-containing silanes such as dimethoxysilane.

  In the liquid gasket of the present invention, a silanol condensation catalyst can be used as the component (D). The silanol condensation catalyst is a catalyst for crosslinking and curing the oxyalkylene polymer having a crosslinkable silicon group as the component (A). Examples of silanol condensation catalysts include alkyl titanates, organosilicon titanates, bismuth tris 2-ethylhexoate, dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, dioctyltin didibasate, dioctyltin dilaurate , Metal salts of carboxylic acids such as dioctyltin maleate, dioctyltin diacetate, tin octylate, tin naphthenate, etc .: amine salts such as dibutylamine-2-ethylhexoate, and other acidic and basic catalysts Can give. Among these, an organic tin compound is preferable, a tetravalent tin compound is more preferable, and a dioctyltin compound which is a tetravalent tin compound such as dioctyltin diversate is particularly preferable.

  It has been found that when a tetravalent tin compound, particularly a dioctyl tin compound, is used, the aminosilane compound serves as a co-catalyst to increase the curing rate. However, in the liquid gasket of the present invention, since the amount of aminosilane compound used is small, the aminosilane compound does not sufficiently function as a promoter. The present inventors have found that by further adding an amine compound having no crosslinkable silicon group as the component (E), the curing rate is increased without increasing the adhesion of the liquid gasket to the substrate such as the housing member. It was. As the amine compound of component (E), primary to tertiary amines can be used. In particular, amines used as curing agents for epoxy resins can be suitably used.

  Primary amines include aliphatic amines (diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, polymethylenediamine (trimethylhexamethylenediamine, polyetherdiamine, diethylaminopropylamine)), alicyclic amines (men Sendiamine), aliphatic amines containing aromatic rings (metaxylenediamine), aromatic amines (metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, aromatic diamine eutectic mixture), 3,9-bis (3-aminopropyl) ) -2,4,8,10-tetraspiro [5,5] undecane) and modified amines (amine adducts, cyanoethylated polyamines). Secondary and tertiary amines include linear secondary amines, linear tertiary amines, tetramethylguanidine, piperidine, pyridine, picoline, benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4 , 6-Trisdimethylaminophenol.

  When using a silanol condensation catalyst (D), it is good to use in the range of 0.1-20 mass parts normally with respect to 100 mass parts of (A) component, Preferably it is the range of 0.2-10 mass parts. Moreover, when using together the amine compound (E) which does not have a crosslinkable silicon group as a co-catalyst, 0.1-20 mass parts of amine compounds which do not have a crosslinkable silicon group with respect to 100 mass parts of (A) component. It is good to use it in the range of 0.2-10 mass parts preferably.

  In the liquid gasket of the present invention, a filler can be used as the component (F). Examples of fillers include reinforcing fillers such as fumed silica, precipitated silica, silicic anhydride and carbon black; calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, hardened titanium, bentonite, organic bentonite Further, fillers such as ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil and shirasu balloon; and fibrous fillers such as asbestos, glass fibers and filaments can be used.

  When it is desired to obtain a cured product having high strength by using these fillers, fumed silica, precipitated silica, anhydrous silicic acid, hydrous silicic acid and carbon black, surface-treated colloidal calcium carbonate, calcined clay, clay Favorable results can be obtained by using a filler selected from active zinc white and the like. Among them, fumed silica, surface-treated colloidal calcium carbonate or carbon black has a small average particle size of 1 μm or less, and when these fillers are used, the liquid gasket of the present invention is applied in an uncured state. In this case, sagging or the like does not occur (excellent thixotropy) and workability is improved. In particular, when fumed silica and / or surface-treated colloidal calcium carbonate and carbon black are combined, a liquid gasket having excellent thixotropy and good workability can be obtained.

  In addition, when it is desired to obtain a cured product having low strength and large elongation, a filler selected from titanium oxide, calcium carbonate, magnesium carbonate, talc, ferric oxide, zinc oxide, shirasu balloon, etc. is mainly used. Preferred results are obtained when used. Of course, these fillers may be used alone or in combination of two or more.

  When a filler is used, it is preferably added in a slightly smaller amount than in the case of a normal adhesive or sealing material, and is in the range of 0.1 to 300 parts by weight, preferably 1 to 200 parts per 100 parts by weight of component (A). It is good to use in the range of mass parts, more preferably 5-100 mass parts. When fumed silica and / or surface-treated colloidal calcium carbonate and carbon black are combined, the amount of fumed silica or the amount of surface-treated colloidal calcium carbonate or the amount of fumed silica and / or surface-treated colloidal calcium carbonate is substantially the same as above. (A) It is good to use in the range of 0.1-300 mass parts with respect to 100 mass parts of component, Preferably it is the range of 1-200 mass parts, More preferably, it is 5-100 mass parts. When fumed silica and surface-treated colloidal calcium carbonate are used in combination, the ratio of fumed silica to surface-treated colloidal calcium carbonate is preferably 1/100 to 100/1, more preferably 1/100 to 1/10, in terms of mass ratio. Moreover, it is preferable to use the amount of carbon black in the range of 0.1-10 mass parts with respect to 100 mass parts of (A) component, Furthermore, 0.1-5 mass parts.

  Further, a dehydrating agent, an antioxidant, a light stabilizer, a diluent, a plasticizer, a lubricant, a pigment, a foaming agent, and the like can be added to the liquid gasket of the present invention.

  The dehydrating agent prevents the (A) component oxyalkylene polymer having a crosslinkable silicon group from being crosslinked during storage. A silicate can be mentioned as a dehydrating agent. For example, tetraalkoxysilane or a partially hydrolyzed condensate thereof may be mentioned. More specifically, tetramethoxysilane, tetraethoxysilane, ethoxytrimethoxysilane, dimethoxydiethoxysilane, methoxytriethoxysilane, tetra-n-propoxy Tetraalkoxysilanes (tetraalkyl silicates) such as silane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra-i-butoxysilane, tetra-t-butoxysilane, and partial hydrolysis condensates thereof Can be mentioned. In addition, alkyl silanes such as hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, phenyl group-containing silanes such as phenyltrimethoxysilane, vinyl unsaturated groups such as vinyltrimethoxysilane and vinyltriethoxysilane Containing silanes can also be used.

  0.1-20 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for the mixture ratio of a dehydrating agent, 1-10 mass parts is more preferable. A dehydrating agent may be used independently and may use 2 or more types together.

  Examples of the antioxidant include p-phenylenediamine-based antioxidants, amine-based antioxidants, hindered phenol-based antioxidants, and secondary antioxidants such as phosphorus-based antioxidants and sulfur-based antioxidants. It is done. Although the addition amount of antioxidant is not specifically limited, Preferably it is 0.1-10 mass parts with respect to 100 mass parts of (A) component, More preferably, it can be used in 0.5-5 mass parts.

  Various types of light stabilizers are known, and are described in, for example, “Antioxidant Handbook” issued by Taiseisha, “Degradation and Stabilization of Polymer Materials” (235-242) issued by CM Chemical Co., Ltd. Although various things are mentioned, it is not necessarily limited to these. Among the light stabilizers, ultraviolet absorbers are preferable, and specifically, Tinuvin P, Tinuvin 234, Tinuvin 320, Tinuvin 326, Tinuvin 327, Tinuvin 329, Tinuvin 213 (all of which are manufactured by Ciba Geigy Japan), etc. Examples include benzotriazole compounds, triazine compounds such as Tinuvin 1577, benzophenone compounds such as CHIMASSORB 81, and benzoate compounds such as Tinuvin 120 (manufactured by Ciba Geigy Japan).

  Further, hindered amine compounds are also preferable, and specific examples of such compounds include those described in JP-A-2006-274084, but are not limited thereto. Furthermore, since the combination of the ultraviolet absorber and the hindered amine compound may exhibit more effect, it is not particularly limited, but may be used in combination, and it is preferable to use in combination. The light stabilizer may be used in combination with the above-mentioned antioxidant, and is particularly preferable because the effect is further exhibited by using it together, and the weather resistance may be improved. Tinuvin C353, Tinuvin B75 (all of which are manufactured by Ciba Geigy Japan, Inc.) in which a light stabilizer and an antioxidant are mixed in advance may be used.

  It is preferable that the usage-amount of a light stabilizer is the range of 0.1-10 mass parts with respect to 100 mass parts of (A) component. If it is less than 0.1 parts by mass, the effect of improving the weather resistance is small, and if it exceeds 10 parts by mass, there is no great difference in the effect, which is economically disadvantageous.

  Diluents include, for example, aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, heptane and octane, alicyclic hydrocarbons such as methylcyclohexane, and petroleum solvents from gasoline to kerosene fractions. Dimethyl adipate (DMA), 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB), esters such as ethyl acetate and butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, methylcyclohexanone, etc. Ethers such as ketones, tetrahydrofuran, cellosolve acetate, butyl cellosolve acetate, N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc. Of nitrogen-containing solvents It is below.

  When using a diluent, it is good to use in the range of 0.5-50 mass parts normally with respect to 100 mass parts of (A) component, Preferably it is 1-30 mass parts.

  Specific examples of the plasticizer include phthalic acid esters such as dioctyl phthalate, dibutyl phthalate and butyl benzyl phthalate; aliphatic dibasic acid esters such as dioctyl adipate, isodecyl succinate and dibutyl sebacate; diethylene glycol dibenzoate, penta Glycol esters such as erythritol ester; aliphatic esters such as butyl oleate and methyl acetylricinoleate; phosphate esters such as tricresyl phosphate, trioctyl phosphate and octyl diphenyl phosphate; dibasic acid and dihydric alcohol Polyester plasticizers such as polyesters; Polyethers such as polypropylene glycol and its derivatives; Hydrocarbon plastics such as paraffinic hydrocarbons, naphthenic hydrocarbons, and paraffin-naphthene mixed hydrocarbons S; chlorinated paraffins; low molecular weight acrylic ester polymer and the like. These plasticizers may be used alone or in combination of two or more. In particular, when an acrylic ester polymer is used, the weather resistance of the cured product can be improved. When using a plasticizer, it is good to use in the range of 5-100 mass parts normally with respect to 100 mass parts of (A) component, Preferably it is the range of 10-50 mass parts.

  The method for producing the liquid gasket of the present invention is not particularly limited. For example, the liquid gasket can be produced by mixing a predetermined amount of a compounding substance and degassing and stirring. The liquid gasket of the present invention can be a one-component type or a two-component type as required, but can be suitably used particularly as a one-component type. The liquid gasket of the present invention can be cured at normal temperature by atmospheric moisture, and is suitably used as a normal temperature moisture-curing liquid gasket. However, curing may be accelerated by heating as necessary. . Moreover, it is preferable that the liquid gasket of this invention does not contain the solvent whose flash point is less than 65 degreeC.

  The small portable electronic device in which the liquid gasket of the present invention is used is not particularly limited. For example, portable communication devices (for example, mobile phones, PDA terminals, smartphones, tablets, etc.), portable personal computers, digital watches, portable radios, portable televisions, digital cameras, portable digital video recorders, portable CD players, MD players And portable recording / recording / reproducing devices such as DVD players, MP3 players, and digital recorders. The liquid gasket of the present invention can also be used to individually protect the internal electronic circuit, memory, CPU or battery part.

  The liquid gasket of the present invention is used by applying one or both of a plurality of housing members such as a main body and a lid to be sealed and combining the housing members. Since the oxyalkylene polymer having a crosslinkable silicon group is cured by moisture in the air, the curing proceeds if the housing members are left after being combined. If it is desired to increase the curing rate, heating is also possible.

  The housing member can be provided with a groove at a position to be applied and the liquid gasket can be fixed, but the groove is not essential. Housing materials include polyamide resins (nylon, etc.), polycarbonate resins, ABS resins, PMMA resins, and other synthetic resins, synthetic resins made by adding glass fibers to these synthetic resins, SUS, mild steel and other metals, glass Ceramics such as can be used. Among these, synthetic resins, particularly synthetic resins reinforced with glass fibers, are preferable.

  The liquid gasket of the present invention is useful when reworking a small portable electronic device. When reworking, first separate the housing member such as the main body and the lid, but the liquid gasket of the present invention is not firmly bonded to the base material like a normal adhesive, so it is relatively easy to separate. Can do. At this time, the entire liquid gasket remains on one housing member, and part of the liquid gasket does not remain on the other housing member (no adhesive residue), and the interface peels cleanly.

  If the material of the sealed housing member is different, the liquid gasket remains on the material with higher peel strength. When the material of the sealed housing member is the same, the liquid gasket remains on the housing member on the side where the liquid gasket is applied. When the gasket is mechanically fixed by a groove or the like provided in one housing member, the liquid gasket remains in the fixed housing member. Further, when the housing member is separated, if a part of the liquid gasket is forcibly peeled off, the liquid gasket is peeled off in the housing member on the peeled side. In any case, on the side where the liquid gasket is peeled off, it peels cleanly at the interface with the substrate, and there is no adhesive residue.

  After the housing member is separated and the defective portion is replaced, the liquid gasket remaining on one of the housing members can be sealed again without applying a new liquid gasket.

  The present invention will be described more specifically with reference to the following examples. However, it is needless to say that these examples are shown by way of illustration and should not be construed in a limited manner.

(Synthesis Example 1)
A methanol solution of sodium methoxide (NaOMe) was added to polyoxypropylene diol to distill off the methanol, and allyl chloride was further added to convert the terminal hydroxyl group to an allyl group. Unreacted allyl chloride was removed by devolatilization under reduced pressure, and the resulting metal salt was extracted and removed with water to obtain polyoxypropylene having an allyl group at the terminal. To the resulting allyl group-terminated polyoxypropylene, an isopropanol solution of a platinum vinylsiloxane complex is added and reacted with trimethoxysilane. The weight average molecular weight in terms of PPG (polypropylene glycol) is about 25,000, and an average of 1. A polyoxypropylene-based polymer A1 having 5 terminal trimethoxysilyl groups was obtained.

(Synthesis Example 2)
A methanol solution of sodium methoxide (NaOMe) was added to polyoxypropylene triol to distill off the methanol, and allyl chloride was further added to convert the terminal hydroxyl group into an allyl group. Unreacted allyl chloride was removed by devolatilization under reduced pressure, and the resulting metal salt was extracted and removed with water to obtain polyoxypropylene having an allyl group at the terminal. To the resulting allyl group-terminated polyoxypropylene, an isopropanol solution of a platinum vinylsiloxane complex is added and reacted with trimethoxysilane to have a mass average molecular weight of about 20000 in terms of PPG, and an average of two terminal trimethoxy groups per molecule. A polyoxypropylene polymer A2 having a silyl group was obtained.

(Synthesis Example 3)
Dioctyltin oxide was mixed with diisononyl phthalate, heated and dissolved at 100 ° C. to obtain a silanol condensation catalyst.

Example 1
Oxypropylene having a crosslinkable silicon group obtained in Synthesis Example 1 in a flask equipped with a stirrer, a thermometer, a nitrogen inlet, a monomer charging tube, and a water-cooled condenser at the blending ratio (mass basis) shown in Table 1. Polymer A1, oxypropylene polymer A2 having a crosslinkable silicon group obtained in Synthesis Example 2, tackifying resin, surface-treated colloidal calcium carbonate and fumed silica as filler, hindered phenol as antioxidant A terminal hydroxyl group oxypropylene polymer was mixed as a system antioxidant and a plasticizer. The mixture was kneaded and dehydrated by heating (100 ° C.), degassing and stirring for 2 hours. After cooling, 3-aminopropyltrimethoxysilane as an aminosilane compound, tetravalent tin compound obtained in Synthesis Example 3 as a silanol condensation catalyst, vinyltrimethoxysilane as a dehydrating agent, and normal paraffin as a diluent are added to the mixture and mixed. A liquid gasket was prepared by stirring.
About the prepared liquid gasket, sclerosis | hardenability, workability | operativity, waterproofness, peelability, and the waterproofness of the peeled liquid gasket were evaluated. The evaluation method is as follows.

(Curable)
According to JIS A 1439 5.19 tack-free test, the finger-drying time (TFT) of the liquid gasket obtained in an environment of 23 ° C. and RH 50% was measured to evaluate curability. Within 20 minutes, ◎, within 21-45 minutes, ○, 45-120 minutes, Δ, 121 minutes or more, x.

(Dischargeability)
Using a dispenser robot equipped with a needle having an inner diameter of 0.61 mm as a discharge needle, a pressure of 100 kPa was applied for 5 seconds, and the discharge amount of the obtained liquid gasket was measured. A discharge amount of 10.0 mg or more was rated as “◯”, 5.0 to 9.9 mg or less as “Δ”, and 4.9 mg or less as “x”.

(Sagging)
The sagging (deformation) over time of the beads discharged from the dispenser robot used for the evaluation of the dischargeability was evaluated. The case where there was no dripping was marked as ◎, the case where there was a little dripping, ○, the case where there was quite dripping, △, and the case with large dripping was marked as ×.

(Initial waterproof)
Using a dispenser robot equipped with a needle having an inner diameter of 0.61 mm as a discharge needle, a liquid gasket obtained on a polycarbonate plate reinforced with glass fibers having a length of 130.00 mm, a width of 60.00 mm, and a thickness of 2.00 mm After coating, another sheet of anodized aluminum of the same size was laminated to cure the liquid gasket. The polycarbonate carbonate-alumite aluminum plate laminated and bonded in a water tank having a water depth of 1.0 m was immersed for 30 minutes, and the presence or absence of water intrusion into the gasket was visually determined. A sample without water intrusion was marked with ◯, and a sample with water intrusion was marked with ×.

(Peelability)
The polycarbonate carbonate-alumite aluminum plate laminated and bonded was peeled off, and the interfacial fracture between the polycarbonate or the alumite aluminum and the adhesive was evaluated as ◯, and the cohesive failure of the adhesive was evaluated as x. In all the examples, in the case of interface peeling, the gasket remained on the alumite aluminum and was peeled off.

(Water resistance of peeled liquid gasket)
The polycarbonate carbonate-alumite aluminum plate laminated and bonded was peeled off once and then bonded again. After standing for 24 hours in an environment of 23 ° C. and 50% RH, the polycarbonate / alumite aluminum plate that has been pasted again is immersed in a water tank with a depth of 1.0 m for 30 minutes. Judged. A sample without water intrusion was marked with ◯, and a sample with water intrusion was marked with ×.

(Examples 2 to 4)
A liquid gasket was prepared in the same manner as in Example 1 except that the tackifying resin amount shown in Table 1 was used, and each characteristic was evaluated.

(Examples 5-6)
A liquid gasket was prepared in the same manner as in Example 1 except that the tackifying resin amount and aminosilane compound amount shown in Table 1 were used, and each characteristic was evaluated.

(Comparative Examples 1-2)
A liquid gasket was prepared in the same manner as in Example 1 except that the tackifying resin amount and aminosilane compound amount shown in Table 1 were used, and each characteristic was evaluated.

(Example 7)
A liquid gasket was prepared in the same manner as in Example 3 except that the carbon black shown in Table 1 was further used, and each characteristic was evaluated.

(Example 8)
A liquid gasket was prepared in the same manner as in Example 3 except that an amine compound having no crosslinkable silicon group shown in Table 1 was used, and each characteristic was evaluated.

Example 9
A liquid gasket was prepared in the same manner as in Example 3 except that carbon black and an amine compound having no crosslinkable silicon group shown in Table 1 were used, and each characteristic was evaluated.

(Examples 10-13, Comparative Examples 3-4)
Evaluation was performed in the same manner as in Examples 1 to 4 and Comparative Examples 1 and 2 except that a polyamide resin reinforced with glass fiber was used instead of the polycarbonate plate reinforced with glass fiber. The results are shown in Table 2. Examples 10 to 13 and Comparative Example 3 except that a polycarbonate-ABS resin alloy, ABS resin, polymethyl methacrylate resin, and chemically tempered glass reinforced with glass fiber were used instead of the polyamide resin reinforced with glass fiber. Although the same evaluation as -4 was performed, the same evaluation result was obtained. Moreover, although the liquid gasket of Examples 1-9 was used for the seal of the mobile phone which has the housing member made from the polyamide resin actually reinforced with the glass fiber, it had sufficient waterproof rework property.

The addition amount in the composition of the table is shown in parts by mass, and details of the compounding substances are as follows.
* 1 Polymer A1 obtained in Synthesis Example 1, linear polymer having a weight average molecular weight of 25000, a main chain structure of polyoxyalkylene, and having a trimethoxysilyl group as a crosslinkable silicon group * 2 Synthesis Polymer A2 obtained in Example 2, branched polymer having a weight average molecular weight of 20000, a main chain structure substantially polyoxyalkylene, and having a trimethoxysilyl group as a crosslinkable silicon group * 3 Mitsui Chemicals Product name: FTR6100
* 4 Product name: KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.
* 5 Tetravalent tin compound obtained in Synthesis Example 3 * 6 Product name: Versamine EH30, manufactured by Cognis
* 7 Product name: Calfine 500, manufactured by Shiraishi Kogyo Co., Ltd.
* 8 Product name: Leoroseal QS-20, manufactured by Tokuyama Corporation
* 9 Mitsubishi Chemical, trade name: MCF88
* 10 Shin-Etsu Chemical Co., Ltd., trade name: KBM-1003
* 11 Product name: SONGONOX 2450, manufactured by SONGWON
* 12 Product name: N-11, manufactured by JX Nippon Oil & Energy Corporation
* 13 Product name: Mitsui Polyol Diol-3000, molecular weight 3000, manufactured by Mitsui Chemicals, Inc.

Claims (3)

(A) 100 parts by mass of an oxyalkylene polymer having a hydrolyzable group bonded to a silicon atom and having a silicon-containing group that can be crosslinked by forming a siloxane bond,
(B) An on-site mold for a small portable electronic device containing 50 to 250 parts by mass of a tackifying resin and (C) 0.01 to 0.8 parts by mass of an aminosilane compound , the on-site mold On-site molded liquid gasket for small portable electronic devices, characterized in that the liquid gasket is a FIPG, that is, a gasket obtained by applying an uncured liquid material to a portion to be sealed and sandwiching a housing member, followed by curing. .   A small portable electronic device using the on-site molded liquid gasket for the small portable electronic device according to claim 1. A method for reworking a small portable electronic device,
(A) As an in-situ molded liquid gasket for small portable electronic devices, (A) an oxyalkylene system having a hydrolyzable group bonded to a silicon atom and a silicon-containing group that can be crosslinked by forming a siloxane bond A step of preparing 100 parts by mass of a polymer, (B) a tackifying resin of 50 to 250 parts by mass, and (C) 0.01 to 0.8 parts by mass of an aminosilane compound;
(B) a step of applying the liquid gasket to a portion to be sealed of one housing member of a small portable electronic device in an uncured state and sandwiching the other housing member;
(C) a step of curing the uncured liquid gasket;
(D) removing a housing member of a small portable electronic device that requires rework after curing and replacing internal components; and (e) re-sealing the housing member using the cured liquid gasket as it is. A method for reworking a small portable electronic device comprising a step.