JPS604576A - Pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE:To provide the titled solventless composition having excellent tack (initial tackiness), weather resistance and heat resistance, etc., hardly necessitating the dilution with a solvent for use, and containing a polymer obtained by polymerizing a polymerizable monomer in the presence of a specific polyethyer. CONSTITUTION:The objective composition contains a polymer obtained by polymerizing a polymerizable monomer [preferably butyl (meth)acrylate, etc.] in the presence of a polyether containing the recurring unit of formula -R<1>-O- (R<1> is 1-8C bivalent hydrocarbon group) and at least one olefin group (e.g. the group of formula I , II, etc.) on an average [preferably a polymer having a molecular weight of 500-30,000 and containing the reactive silicon group of formula III(RI is 1-20C bivalent organic group; RII is univalent hydrocarbon group, etc.; a is 0-3; b is 0-2; c is 0 or 1; 1<=a+b<=4; x is silanol group, etc.; m is 0-18)].

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a novel pressure-sensitive adhesive composition comprising a polymer obtained by polymerizing a polymerizable monomer in the presence of a polyether.

Conventionally, rubber-based, acrylic-based, silicone-based, and other pressure-sensitive adhesives have been used, but rubber-based adhesives have insufficient heat resistance, and acrylic-based adhesives have tack ( The disadvantage is that the initial adhesion is poor. Silicone-based materials have fewer drawbacks seen in rubber-based and acrylic-based materials and have superior performance, but are extremely expensive and have a limited range of use.

In order to compensate for the above-mentioned drawbacks, pressure-sensitive adhesives have been proposed in which polymerizable monomers such as acrylic/I/acid esters and styrene are graft-polymerized onto natural rubber or synthetic rubber. has not been fully achieved. Furthermore, conventional rubber adhesives not only require complicated mechanical processes such as mastication, but also require a large amount of solvent like acrylic adhesives, which poses pollution and safety issues. be.

The present inventors have conducted extensive research aimed at improving the above-mentioned drawbacks of conventional pressure-sensitive adhesives. As a result, the polymers and polymers obtained by polymerizing polymerizable monomers in the presence of polyether are We have found that they are useful as pressure adhesives, i.e. the main chain essentially has the general formula: %, where R1 represents a divalent hydrocarbon group having 1 to 8 carbon atoms. A pressure-sensitive adhesive composition comprising a polymer obtained by polymerizing a polymerizable monomer in the presence of a polyether containing repeating units and having on average at least one olefin group in the molecule. By using
It is possible to provide a low-cost, solvent-free pressure-sensitive adhesive that not only has excellent durability such as weather resistance and heat resistance, which are the advantages of acrylic adhesives, but also requires almost no dilution with solvents. The present inventors have discovered that this remarkable effect can be changed, and have completed the present invention.

The polyether used in the present invention may be one in which repeating units such as ``Tato'' are used alone or in a mixture of two or more and polymerized. Linear and/or branched polyethers are used, but especially polyoxy Propylene is preferred. The molecular weight of mW polyether is 500 to 30
,000 is preferred. If the molecular weight is less than 500, the cohesive force tends to decrease, while if it exceeds 30,000, the rubbery properties such as occlusion resistance are likely to be lost.

In the present invention, examples of the olefin group contained in the molecule include the following olefin groups. From the viewpoint of ease of grafting, it is preferable that at least one olefin group is contained in the molecule on average. Polyethers that already have reactive silicon functional groups in their molecules are also useful for crosslinking polymers.

A specific method for producing polyether having at least one olefin group in the molecule used in the present invention is disclosed in JP-A-54-
6097, or by adding an olefin-containing epoxy compound such as allyl glycidyl ether to copolymerize an epoxy compound such as ethylene oxide or propylene oxide. It can be produced by methods such as introducing an olefin group into the side chain.

In the present invention, it is further preferred that the polyether molecule has at least one reactive silicon functional group on average in a side chain or terminal. The reactive silicon functional group is one that condenses and reacts with moisture or additives, such as a hydrolyzable group or silanol group bonded to an ion atom, and is typically represented by the general formula (5). :(wherein, R1
is a 2f + IIi group having 1 to 2 carbon atoms, R11
is hydrogen or a monovalent organic group having 1 to 20 carbon atoms; R1 is the same or different monovalent hydrocarbon group or triorganosiloxy group; a is 0.1.2 or 3; b is 0.1 or 2; , c is 0 or 1, provided that 1 < a + b ≦ 4
, X is a different or similar group selected from a sylyl group or a hydrolyzable group, and m is a functional group represented by λ representing an integer selected from 0 to 18.

The polyether having the above-mentioned functional group is a silicon hydride compound represented by the general formula (6): General formula (7)
:% Formula % (7) (In the formula, R1, RII, o are the same as above) A polyether having an olefin group is combined with platinum black, chloroplatinic acid, platinum alcohol compound, platinum olefin complex, platinum aldehyde It can be produced by q) in which an addition reaction is carried out using a platinum-based compound such as complex, platinum ketone humplex, etc. as a catalyst. In the general formula (6), R1 is the same or different monovalent hydrocarbon group having 1 to 20 carbon atoms, such as an alkyl group such as methyl or ethyl; a cycloalkyl group such as cyclohexyl; or an aryl group such as a fecol group. ; Triorganosiloxy selected from aralkyl groups such as benzyl group, and further represented by the general formula: % formula % (wherein R' represents the same or different monovalent hydrocarbon group having 1 to 20 carbon atoms; In the general formula (6), X represents a silanol group or a different or similar hydrolyzable group, but it also includes a halogen group, a hydride group, an alkoxy group,
Examples include acyloxy group, bovine toximate group, amine group, amide group, aminooxy group, mercapto group, and alkenyloxy group. Specific examples of silicon hydride compounds represented by the general formula (6)7, ′, ′ are halogenated siphons such as trichlorosilane, methyldichlorosilane, dimethylchlorosilane, and trimethylsiloxydichlorosilane; Alfoxysilanes such as methoxysilane, triethoxysilane, methyldimethoxysilane, phenyldimethoxysilane, 1.3.3.5.5.7.7-hebutamethyl-1,1-dimethoxytetrasiloxane; methyldiacetoxysilane , acyloxysilanes such as trimethylsiloxymethylacetoxysilane; ketoximate silanes such as di(dimethylketoximate)methylsilane, bis(cyclohexylketoximate)methylsilane, bis(diethylketoximatenottrimethylsiloxysilane); Hydrosilanes such as dimethylsilane, trimethylsilanemethylsilane, 1,1-dimethyl-2,2-dimethyldisiloxane; alkenyloxysilanes such as methyltri(isopropenyloxy)silane, but are limited to these It is not something that will be done.

In this method, after reacting the silicon hydride compound of general formula (6) with the polyether having an olefin group of general formula (7), some or all of the X groups can be further hydrolyzed. or hydroxyl group. For example, when the X group is a halogen group or a hydride group, it is preferable to use it after converting it into an alkoxy group, an acyloxy group, an aminooxy group, an alknyloxy group, a hydroxyl group, or the like.

In general formula (7), R■ is a hydrogen atom or has 1 carbon atom
-20 monovalent organic groups, preferably a hydrogen atom or a hydrocarbon group, and particularly preferably a hydrogen atom. R
1 is preferably a divalent organic group having 1 to 20 carbon atoms, either the same or different, or a hydrocarbon group and a hydrocarbon group containing an ether bond, an ester bond, a urethane bond, or a carbonate bond. and <i methylene groups are preferred.

The polymerizable monomer used in the present invention has the general formula (1): (wherein R2 is a hydrogen atom, a halogen atom, or a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, R3 is the same group as R2, a substituted or non-monosubstituted monovalent aromatic hydrocarbon group, an alkenyl group, a carboxyl group,
(representing an acyloxy group, an alkoxycarbonyl group, a nitrile group, a pyridyl group, an amide group, or a glycidoxy group), preferably a vinyl monomer represented by the general formula (3)21 (wherein R2 is the same as above and R6 is (represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 2 carbon atoms), or a vinyl monomer represented by the general formula (2): (in the formula, R4
is a monovalent hydrocarbon group selected from γ-alkyl group, asinol group, and aralkyl group having 1 to 10 carbon atoms; R5 is polymerizable 2
An organic residue having a heavy bond, X is a hydrolyzable group, and n is 1.
(representing an integer of 2.6), preferably a vinyl monomer (vinyl compound) represented by the general formula (4): (wherein, R2, R4, and n are the same as above, and R is carbon Number 1~
A vinyl monomer represented by 10 divalent hydrocarbon groups (R8 represents a substituted or unsubstituted divalent hydrocarbon group having 1 to 8 carbon atoms) is used.

Examples of the vinyl monomer represented by general formula (1) or general formula (3) include ethyl acrylate, butyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, and acrylic acid 2- Acrylic acids such as ethylhexyl, MEC 1-norate 2-ethylhexyl, acrylic acid, benzyl methacrylate,
Methacrylic acid esters; carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, and acid hydrates such as maleic anhydride; epoxy compounds such as glycidyl acrylate, glycidyl methacrylate; diethylaminoethyl acrylate, diethylaminoethyl methacrylate , amino compounds such as aminoethyl vinyl ether; acrylamide, methacrylamide, itaconic diamide, a-ethyl acrylamide, crotonamide, 7-malva diamide, maleic diamide, N
- Amide compounds such as butoxymethylacrylamide, N-butoxymethylmethacrylamide; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxy vinyl ether, N-methylol acrylamide, Aronix 5700 (manufactured by Toagosei Chemical Co., Ltd.) Vinyl compounds containing hydroxyl groups; acrylonitrile, iminol methacrylate, styrene, a-methylstyrene, chlorstyrene 1-u (l:, vinyl, vinylidene chloride, vinyl acetate, Examples include vinyl propionate, vinylpyridine, 7'tadiene, chloroprene, imbutylene, propylene, and the like.

Specifically, OH3 0H2 = OHSi (OCH3)2, OH2
= OHSi (OCH3)3, OH3 GH2= OHSiO12, OH2 = OHSi (OCH3)3\01(2
=OHS:1. (OOH20H3) 3 10
H2: OI (SiO/!3, 1 0H2= OHOO (OH2) 3Si (oaH2
0H3) 3'-.

1 OH3 0H2” = O − Co (OH2) 3Si
(OCH3) 3, 1 OH3 0H2 = 0 00 (OH2)3Sj (O surrounding 2
0H3) 3, 1 OH3 0H2 = O - 00 (OH2) 3Si(
] 13 , 1 0 0H3 0 1 0H3 1 ■, etc. can be exemplified. The vinyl monomer is one or two types.
Although more than one species can be used in combination, from the viewpoint of compatibility with polyether and adhesiveness, acrylic esters having alcohols having 2 to 14 carbon atoms, especially butyl acrylate and/or 2-ethylhexyl acrylate, are preferred. It is preferable to use 50 mol% or more of the total amount of polymerizable monomers as main components. The number of carbon atoms in those alcohols is 2~
Acrylic ester No. 14 contributes to the development of tack and adhesive strength together with polyether, but other monomers are used to impart cohesive strength and adhesive strength, but have a negative impact on compatibility with polyether and adhesive properties. It is used as a copolymerization component to a certain extent. In particular, polymerizable silane compounds (polymerizable monomers with silicon functional groups) and functional monomers such as acrylic acid, methacrylic acid, and maleic anhydride can increase cohesive strength and adhesive strength by copolymerizing a small amount. It has an effect.

In particular, it is preferable to copolymerize a polymerizable silane compound because it can form a thermally stable silxane crosslink by co-condensing with the reactive silicon functional groups present in the polyether. The amount used is preferably 0.1 to 10 mol% of the total polymerizable monomers.

In the present invention, the polymerizable monomer is polymerized in the presence of a polyether having at least one olefin group in the molecule, but in polymerizing the polymerizable monomer M in the presence of the polyether, A predetermined polymerizable monomer and a radical polymerization initiator are added to the polyether and heated under a nitrogen gas stream while stirring, or the radical polymerization initiator is added to the heated polyether under a nitrogen gas stream. It can be easily dispersed by a method such as dropping a predetermined amount of a pre-dissolved polymerizable monomer while stirring. In case of M, a solvent may or may not be used. If a solvent is used, examples include solvents such as benzene, toluene, xylene, hexane, cyclohexane, ethyl acetate, and methyl ethyl ketone. Polyether does not play the role of a solvent, so it can be polymerized without a solvent.

In the present invention, the ratio of the polyether to the polymerizable monomer is polyether/polymerizable monomer or 50/1 to 1.
It can be used in any ratio within the range of 150 (weight ratio). In particular, polyethers have excellent compatibility with polymers whose main components are acrylic esters, and they mix well over a wide range.This is because the olefin groups contained in polyethers can bind polymerizable monomers. This is because it plays a role in increasing the grafting efficiency during polymerization, thereby further increasing the compatibility of the polymer of polyether and the polymerizable monomer.

The radical polymerization initiator is not particularly limited, and includes azobisinbutyronitrile, benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, para-t
In addition to the usual compounds such as -butyl perbenzoate, special radical polymerization σ initiators such as bis-azodicyanovaleric acid, and even containing reactive silicon functional groups, such as ((0H30) 3SiGH20H20H20-N =
)2, OH3 OH3 and the like.

The initiator may be used alone or in a mixture of two or more,
0.5 to b (the same applies below) to the polymerizable monomer. In the polymerization reaction, a chain transfer agent may or may not be used, but if used, in addition to ordinary compounds such as mercaptans such as lauryl mercaptan and dodecyl mercaptan and halogen-containing compounds, Containing reactive silicon functional groups, e.g. H80H20) f20H2si (0OH3) 3%
0I (3 H80H2G) f20H2si (0OH3) 2, (
(0H30) 3SiOH2flH20H2S -)
, ((OH30)35t(ys -)2, etc. can also be used. They may be used alone or in a mixture of two or more. The polymerization temperature depends on the type of radical polymerization initiator, but is usually 50 to Polymerization is carried out at 150°C.

The polymerized polymer 900 obtained in this way has considerable tackiness by itself, but in the present invention, it is necessary to add a catalyst, a tackifying resin, an anti-aging agent, a filler, a softening agent, etc. Substances such as agents and additives may be blended, and other compatible polymers may be blended.

As the above-mentioned polymers, acrylic polymers and various polyethers are particularly preferable, and in particular, acrylic polymers whose main component is (meth)acrylic acid ester whose alkyl group has 2 to 14 carbon atoms, and No. 45-56319, Special Publication No. 12154 (1972), Special Publication No. 30711 (1977)
No., Special Publication No. 4e-+6960 and Japanese Patent Publication No. 52-73
Examples include polyethers having a silicon functional group represented by the general formula (5), which are proposed in each publication of No. 998.

As mentioned above, the catalysts that may be added as necessary include:
Examples include known silanol condensation catalysts. Specific examples include reactions between metal carboxylates such as dibutyltin dilaurate, tin dioctylate, dibutyltin maleate, and dioctyltin laurate, and reactions between dialkyltin oxides and ester compounds such as dibutyltin oxide and dioctyl phthalate or dioctyltin oxide and tetraethyl orthosilicate. Examples include compounds, alkyl titanates, amines, and acid/base compounds.

As the tackifying resin, known tackifying resins such as rosin, modified rosin, rosin ester, terpene resin, terpene-phenol resin, phenol resin, and tackifying resin are used.

The pressure-sensitive adhesive composition of the present invention can be modified not only by the polymerizable monomer composition found in conventional acrylic pressure-sensitive adhesives, by modification by molecular weight, or by polymerization operations such as multi-stage polymerization. , composition ratio of polyether and polymerizable monomer, polyether structure, i.e., molecular weight, degree of branching, type of olefin and silicon functional groups, and ■, as well as tackifying resin formulation, such as that found in rubber-based pressure-sensitive adhesives. Since it can be modified by, for example, general packaging, electrical insulation, corrosion prevention, adhesive masking, and surface preservation, it can be used in a wide range of applications.

Although the composition of the present invention is particularly useful as a pressure-sensitive adhesive for the above reasons, it can also be used as a general adhesive, a sealant, or a coating material.

Next, the composition of the present invention will be specifically explained using Examples, but the present invention is not limited to these Examples.

Reference Example 1 Diol type polyoxypropylene glycol with an average molecular i of 3200 (manufactured by Sanyo Chemical Industries, Ltd., PP-4000)
) 5209 was placed in a nitrogen-substituted pressure-resistant autoclave with an internal volume of 11, and 40.89% of powdered sodium hydroxide (purity 98%) was added, and the temperature was raised to 60 ° 0.
Stir for hours. Next is bromoctetramethane 7.769
After stirring at 60°O for 10 hours, 9.2 g of allyl chloride was added and the reaction was continued for an additional 10 hours.

After cooling, the contents were taken out and transferred to a separable flask No. 81. After 1.51% n-hexane was added thereto and stirred to obtain a homogeneous state, a 3% by weight sulfuric acid aqueous solution was added i, sz and stirred for 1 hour. After standing for 1 hour, the mixture was separated into two layers: a transparent hexane layer and an aqueous layer. At this time, the pH of the aqueous layer was 6 or less. The hexane layer is separated and taken out, and by removing n-hexane with an evaporator, the average molecule i
8000, a polyether (A) in which 94% of the terminals were converted to allyl ether was obtained.

Reference Example 2 300 g of polyale (A) obtained in Reference Example 1 was placed in a nitrogen-substituted 0.51 pressure autoclave.
After adding 0.39% of a 10% by weight solution of chloroplatinic acid in isopropyl alcohol and mixing uniformly, 409% of methyldimethoxyhydrosilane was added, and the mixture was heated to 90°Q and stirred for 4 hours.

Gas chromatography of the reaction mixture, infrared absorption spectrum and elemental analysis of the product after low boiling point substances were removed in vacuo, confirmed that a polyether polymer (B) in which 50% of the terminals were silylated was produced.

Example 1 Polyether (A) obtained in Reference Example 1 209, 2-ethylhexyl acrylate 709, butyl acrylate 20
9. A mixed solution of vinyl acetate 5.0, acrylic acid 2.09, benzoyl peroxide 0.89 and ethyl acetate 5D9 was placed in a 300+nl 4-tube flask, stirred under a nitrogen atmosphere, and polymerized at 80°0 for 6 hours. A homogeneous and transparent polymer solution was obtained.

The obtained solution was applied to a polyester film with a thickness of 25 μm so that the glue thickness after drying was 25 μm, and
After drying at °C for 2 minutes, an adhesive tape with excellent adhesiveness, cohesiveness, and clarity was obtained.

Using the obtained adhesive tape, peeling using the Tack 1 stainless steel plate corrugated body using the Tack 1 stainless steel plate corrugated body using the Tack 1 ball tack method with an inclination angle of 30°. 1 Adhesion area using stainless steel adherend: 25 mm x 25 myns Load: 1 o
Cohesive force was measured by measuring the displacement distance after 15 minutes at oo9. The results are shown in Table 1.

Comparative Example 1 An adhesive tape was obtained in the same manner as in Example 1 except that polyether (A>) was not used.

The performance of the obtained adhesive tape was measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 An adhesive tape was prepared in the same manner as in Example 1 using a natural rubber adhesive, and its performance was measured in the same manner as in Example 1. The results are shown in Table 1.

Table 1 shows that the adhesive tape using the composition of the present invention has good tack, adhesive force, and cohesive force, and is excellent in balance.

Examples 2 to 5 Polyether (B) 1009 obtained in Reference Example 2 was placed in a four-tube flask and heated to 110°C under a nitrogen atmosphere. As shown in Table 2, a mixture of acrylic acid ester and azobisisobutyronitrile was added dropwise over 2 hours while stirring. Stirring was continued for another 4 hours to form a uniform, transparent, and viscous liquid. I got it. Obtained polymer 1009
A transparent adhesive tape was obtained in the same manner as in Example 1 by adding 5 g of an equimolar reaction product of dibdeltin oxide and dioctyl phthalate and mixing them uniformly. Using the obtained adhesive tape, Example 1 Its performance was measured in the same manner. The results are shown in the second delusion.

Example 6 Polyether (B) 1009 obtained in Reference Example 2 was converted into 4
Place in a Tulo flask, add nitrogen, under 7E atmosphere, 110°0
It was heated to A mixture of 97.59 parts of butyl acrylate, 2.59 parts of trimethoxysilylpropyl acrylate, and 4.0 parts of azobisisobutyronitrile was added dropwise to this over 2 hours while stirring. Stirring was continued for a further 4 hours. A uniformly transparent and viscous liquid was obtained.

Using the resulting liquid material, a transparent adhesive tape was obtained in the same manner as in Example 1. Using the obtained adhesive tape, its performance was measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 3 An adhesive tape was prepared in the same manner as in Example 6, except that ethyl acetate was used instead of the polyether (B) used in Example B, and its performance was measured. The results are shown in Table 2.0 Table 2 shows that the adhesive tape using the composition of the present invention has excellent tack, adhesive strength and)
I understand that.

Example 7 The adhesive tapes obtained in Examples 1 to 6 were applied to a stainless steel plate and left at 70°Q for 72 hours or irradiated with a Sunshine Weather-O-meter for 200 hours, but almost no change in adhesive strength was observed.

Further, no adhesive residue on the surface of the adherend or corrosion of the adherend was observed.

From the above facts, it can be seen that the composition of the present invention is also useful as a pressure-sensitive adhesive for surface preservation and masking.

Patent applicant Kanebuchi Chemical Industry Co., Ltd. Shirito Bento 10 Asa-Hana Souyu

Claims (1)

[Claims] 1 The main chain essentially contains a repeating unit represented by the general formula: % formula % (wherein R1 represents a divalent hydrocarbon group having 1 to 8 carbon atoms), A pressure-sensitive adhesive composition comprising a polymer obtained by polymerizing a polymerizable monomer in the presence of a polyether having on average at least one olefin group in the molecule. 2 The polyether contains on average at least 1 molecule in the molecule.
reactive silicon functional groups and a molecular weight of 500 to
The composition according to claim 1, which is go, ooo. 6 The polymerizable monomer has the general formula (1): % formula % (1) (in the formula, R2 is a hydrogen atom), a rogene atom, or a @-substituted or unsubstituted monovalent monovalent compound having 1 to 10 carbon atoms. an aliphatic hydrocarbon group, R3 is the same group as R2, a substituted or unsubstituted monovalent aromatic swollen hydrogen group, an alkenyl group, a carboxyl group, an acyloxy group, an alkoxycarbonyl group, a nitrile group,
(representing a pyridyl group, an amide group, a glycidoxy group) or a vinyl monomer represented by the general formula (2): (wherein R4 is an alkyl group having 1 to 10 carbon atoms) selected from an aryl group and an aralkyl group. Monovalent hydrocarbon group, R5
The composition according to claim 1, which is a vinyl monomer represented by an organic residue having an associative two-clawed bond or a hydrolyzable group, and n is an integer of 1.2. thing. 4 The vinyl monomer represented by the general formula (1) has the general formula (3): represents a hydrogen group), and the vinyl monomer represented by general formula (2) is represented by general formula (4): (wherein R2, R4, and n are the same as above) , R7 has 1 carbon number
to 10 divalent hydrocarbon groups, R8 represents a substituted or unsubstituted divalent hydrocarbon group having 1 to 8 carbon atoms. Composition according to item 6. 5. The composition according to claim 3, wherein the polymerizable monomer is an acrylic ester having an alkyl group having 2 to 14 carbon atoms in an amount of 50 mol% or more based on the total amount of monomers. 6. The composition according to claim 6 or 4, wherein the polymerizable monomer having a silicon functional group is contained in an amount of 0.1 to 10 mol% based on the total amount of polymerizable monomers.