TW201811907A - Self-adsorption foamed sheet - Google Patents

Abstract

Provided is: a self-adsorption foamed sheet formed by shaping in a sheet a foamed body of a resin composition for the self-adsorption foamed sheet, including 100 pts. mass of (meth)acrylic acid ester copolymer resin having a N-methylol group and a glass transition temperature of no more than -10 DEG C, and 1 to 20 pts. mass of a carbodiimide crosslinking agent, thereafter allowing crosslinking reaction of the (meth)acrylic acid ester copolymer resin; and a self-adsorption foamed stacked sheet including an adsorption layer formed of the self-adsorption foamed sheet and a support layer formed of a base material. The self-adsorption foamed sheet and the self-adsorption foamed stacked sheet generate extremely small amount of formaldehyde, have appropriate self adhesion force, and are excellent in adhesiveness and smoothness.

Description

 Self-adsorbing foam sheet  

The present invention relates to a self-adsorptive foamed sheet, a self-adsorptive foamed laminated sheet, a method for producing the same, and a resin composition for obtaining the same.

In recent years, a patch for use as a smooth adherend such as a window glass is a self-adsorbing sheet member made of a foamed material having many fine pores (hereinafter referred to as "self-adsorptive property". Foam sheet"). The adhesive pattern of the self-adsorptive foamed sheet is not adhered to the adhesive, but is adsorbed to the adherend by fine pores, so that it is easy to reattach without sticking to the adhesive, and is suitable for use in interior decoration materials such as wallpapers and the like. Various uses such as materials, posters and stickers, and other materials for advertising. For use in such applications, a substrate such as a resin film is usually laminated on the self-adsorbing foam sheet, and a decoration such as printing is applied to the substrate. Hereinafter, a laminate sheet having an adsorption layer composed of a self-adsorptive foam sheet and a support layer composed of a base material is referred to as a "self-adsorptive foamed laminate sheet".

As the foaming material constituting the self-adsorptive foamed sheet, a resin is conventionally used, and from the viewpoint of excellent various mechanical strengths and weather resistance, an acrylate copolymer is preferably used. However, in the acrylate copolymer, in particular, in order to increase the strength at the time of wetting, a material having an N-methylol group is often used, and in order to increase the strength, a melamine-based crosslinking agent is often used in combination. When an acrylate copolymer having an N-methylol group is used in combination with a melamine-based crosslinking agent, the crosslinking reaction generates a large amount of formaldehyde and remains in the self-adsorptive foamed sheet, thereby causing self-adsorptive foaming. The reason why formaldehyde is generated when a sheet or a self-adsorptive foamed laminate sheet is produced. Conventional formaldehyde is a causative substance of the so-called pathological building syndrome. Therefore, it is strongly required to reduce the amount of production by setting environmental standards, etc., and when such self-adsorbing foam sheets or self-adsorptive foamed laminated sheets are used for wallpapers, etc., problem.

A technique for reducing the amount of formaldehyde generated from a self-adsulating foam sheet, for example, Patent Document 1 discloses a method using a (meth) acrylate copolymer resin having no N-methylol group in a molecule and A resin composition formed by an oxazoline crosslinking agent to produce a self-adsorptive foamed sheet which completely or hardly produces formaldehyde.

Advanced technical literature Patent literature

Patent Document 1 JP-A-2006-176693

However, in Patent Document 1, a (meth) acrylate copolymer resin having a carboxyl group is used instead of the conventional (meth) acrylate copolymer resin having an N-methylol group, in order to obtain a suitable self-adsorption. The force has to increase the gel fraction of the (meth) acrylate copolymer resin, and as a result, the adhesion and smoothness of the self-adsorptive foam sheet are impaired, and it is difficult to balance the self-adsorption force with the foam sheet. Smoothness.

Therefore, an object of the present invention is to provide a self-adsorptive foamed sheet and a self-adsorptive foamed laminated sheet which have an extremely small amount of formaldehyde, have a suitable self-adsorption force, and are excellent in adhesion and smoothness, and provide such a production. And a method for obtaining the resin composition.

As a result of an active discussion of this problem, the present inventors have found that it is possible to satisfy the required characteristics by combining a specified (meth) acrylate copolymer resin and a carbodiimide crosslinking agent.

In other words, the first aspect of the present invention is a resin composition for a self-adsorptive foamed sheet comprising a (meth) acrylate copolymer resin having an N-methylol group and having a glass transition temperature of -10 ° C or lower. 100 parts by mass and 1 to 20 parts by mass of the carbodiimide crosslinking agent.

In the present specification, "(meth)acrylic acid" means "acrylic acid and/or methacrylic acid".

The second aspect of the present invention is a self-adsulating foamed sheet which is formed into a sheet shape by foaming a resin composition for a self-adsorptive foamed sheet of the first aspect of the present invention. It is formed by performing a crosslinking reaction of a (meth) acrylate copolymer resin.

According to a third aspect of the invention, there is provided a self-adsorptive foamed laminated sheet comprising the adsorbent layer comprising the self-adsorbing foam sheet according to the second aspect of the invention and a support layer composed of a substrate.

A fourth aspect of the present invention provides a method for producing a self-adsulating foam sheet, comprising the steps of: preparing a resin composition for a self-adsorptive foam sheet comprising N-methylol group and having a glass transition temperature of 100 parts by mass of a (meth) acrylate copolymer resin of -10 ° C or less and 1 to 20 parts by mass of a carbodiimide crosslinking agent; and self-adsorption by foaming a resin composition for a self-adsorptive foam sheet The step of foaming the resin composition for a foamed sheet; and the step of subjecting the foam to a sheet form to carry out a crosslinking reaction of the (meth) acrylate copolymer resin.

A fifth aspect of the invention is a method for producing a self-adsorptive foamed laminated sheet, which comprises a self-adsorptive foamed laminated sheet comprising an adsorption layer composed of a self-adsorptive foamed sheet and a support layer composed of a substrate. The manufacturing method comprises the steps of: preparing a resin composition for a self-adsulating foamed sheet comprising a (meth) acrylate copolymer resin having an N-methylol group and a glass transition temperature of -10 ° C or lower; 100 parts by mass of the carbodiimide-based crosslinking agent: 1 to 20 parts by mass; and a step of foaming the resin composition from the adsorptive foamed sheet to obtain a foam of the resin composition for a self-adsorptive foamed sheet; And after the foam is formed into a sheet shape on the substrate, a step of laminating the adsorption layer on the support layer by performing a crosslinking reaction of the (meth) acrylate copolymer resin.

In the first, fourth and fifth aspects of the invention, the gel fraction of the (meth) acrylate copolymer resin is preferably 70% or less.

In the third and fifth aspects of the invention, the support layer is preferably a resin film.

According to the present invention, it is possible to provide a self-adsorptive foam sheet and a self-adsorptive foamed laminate sheet which have an extremely small amount of formaldehyde, have a suitable self-adsorptivity, and are excellent in adhesion and smoothness, and provide such a production method and Used to obtain these resin compositions.

Fig. 1 is a flow chart showing an embodiment of a method for producing a self-adsorptive foam sheet of the present invention.

Embodiment of the invention

Hereinafter, embodiments of the present invention will be described. The following description is illustrative of the invention, and the invention is not limited to the embodiments described below. In the present invention, the term "film" also includes "slices", and those referred to as "sheets" also include "films".

 1. Resin composition for self-adsorptive foam sheet  

The resin composition for a self-adsulating foamed sheet of the present invention comprising 100 parts by mass of a (meth) acrylate copolymer resin having an N-methylol group and having a glass transition temperature of -10 ° C or less and a carbodiimide The crosslinking agent is 1 to 20 parts by mass.

 <(Meth)acrylate copolymer resin>  

Hereinafter, the (meth) acrylate copolymer resin used in the present invention will be described. The (meth) acrylate copolymer resin has an N-methylol group and has a glass transition temperature of -10 ° C or lower.

The glass transition temperature of the (meth) acrylate copolymer resin is -10 ° C or lower, preferably -13 ° C or lower. When the glass transition temperature of the (meth) acrylate copolymer resin is adjusted to be equal to or less than the upper limit, the gel fraction of the (meth) acrylate copolymer resin described later can be easily adjusted to be equal to or lower than the specified upper limit. As a result, it is easy to produce a self-adsorptive foamed sheet and a self-adsorptive foamed laminated sheet which have an appropriate self-adhesive force and are excellent in adhesion and smoothness. There is no particular lower limit, but it is preferably -40 ° C or higher.

The (meth) acrylate copolymer resin is composed of 50% by mass or more of a monomer unit derived from a (meth) acrylate monomer and 50% by mass or less of a monomer unit derived from a monomer copolymerizable therewith, preferably. It is composed of 70% by mass or more of the monomer unit derived from the (meth) acrylate monomer and 30% by mass or less of the monomer unit derived from the monomer copolymerizable therewith, and more preferably from (meth) acrylate. 80% by mass or more of the monomer unit of the monomer and 20% by mass or less of the monomer unit of the monomer copolymerizable therewith, and more preferably 85 masses of the monomer unit derived from the (meth) acrylate monomer % or more and 15% by mass or less of a monomer unit derived from a monomer copolymerizable therewith. By setting the monomer unit content of the (meth) acrylate monomer to be within this range, moderate adhesion can be imparted.

In the present invention, the (meth) acrylate copolymer resin has an N-methylol group, which is contained in a monomer unit copolymerizable with the (meth) acrylate monomer, but may also be contained in (methyl) ) in acrylate monomer units.

The (meth) acrylate monomer which can be used in the present invention is not particularly limited, but is preferably formed from the viewpoint of easily lowering the glass transition temperature of the (meth) acrylate copolymer resin to -10 ° C or lower. The (meth) acrylate monomer unit of the homopolymer of glass transition temperature below -20 °C.

The (meth) acrylate monomer forming the homopolymer having a glass transition temperature of -20 ° C or lower is not particularly limited, and examples thereof include ethyl acrylate (the glass transition temperature of the homopolymer is -24 ° C), and acrylic acid n. -propyl ester (ibid., -37 ° C), n-butyl acrylate (ibid., -54 ° C), sec-butyl acrylate (ibid., -22 ° C), n-heptyl acrylate (ibid., -60 ° C), N-hexyl acrylate (ibid., -61 ° C), n-octyl acrylate (ibid., -65 ° C), 2-ethylhexyl acrylate (ibid., -50 ° C), n-octyl methacrylate (ibid.) , -25 ° C) and n-decyl methacrylate (ibid., -49 ° C), etc. to form a (meth)acrylic acid alkyl ester of a homopolymer of glass transition temperature below -20 ° C; 2-methoxy acrylate Ethyl ester (ibid., -50 ° C), 3-methoxypropyl acrylate (ibid., -75 ° C), 3-methoxybutyl acrylate (ibid., -56 ° C) and ethoxymethyl acrylate (ibid.) , -50 ° C), etc., forming an alkoxyalkyl (meth) acrylate such as a homopolymer of a glass transition temperature of -20 ° C or lower. Among them, an alkyl (meth)acrylate which forms a homopolymer having a glass transition temperature of -20 ° C or lower and a (meth)acrylic alkoxylate which forms a homopolymer of a glass transition temperature of -20 ° C or lower are preferred. The base ester is more preferably an alkyl (meth)acrylate which forms a homopolymer of a glass transition temperature of -20 ° C or lower.

Further, if the glass transition temperature of the (meth) acrylate copolymer resin can be adjusted to -10 ° C or lower, methyl acrylate (glass transition temperature of the homopolymer is 10 ° C), methacrylic acid can also be used. Methyl ester (ibid., 105 ° C), ethyl methacrylate (same as above, 63 ° C), n-propyl methacrylate (ibid., 25 ° C), and n-butyl methacrylate (same as above, 20 ° C).

These (meth) acrylate monomers may be used alone or in combination of two or more.

In the monomer copolymerizable with the (meth) acrylate monomer (hereinafter referred to as "monomer for copolymerization"), N-methylol acrylamide and N-methylol methacrylate are required. A monomer having an N-methylol group such as an amine. By using a monomer having an N-methylol group, it is easy to set the gel fraction to be described later to a predetermined upper limit or less. As a result, it is easy to produce a self-adhesive force and an excellent adhesion and smoothness. An adsorptive foam sheet and a self-adsorptive foamed laminate sheet. From this point of view, the monomer usage ratio of the N-methylol group, when the (meth)acrylate copolymer resin is 100% by mass, the monomer unit introduced from the monomer having an N-methylol group It is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 5% by mass or less.

For the monomer for copolymerization, in addition to the monomer having an N-methylol group, other monomers may be used in combination. The other monomer used in combination with the monomer having a N-methylol group is not particularly limited as long as the glass transition temperature of the (meth) acrylate copolymer resin is -10 ° C or lower, and specific examples thereof include α,β-ethylenically unsaturated polycarboxylic acid complete ester, alkenyl aromatic monomer, vinyl cyanide monomer, carboxylic acid unsaturated alcohol ester, olefin monomer, and other monomer having a functional group. These monomers may be used alone or in combination of two or more.

Specific examples of the α,β-ethylenically unsaturated polycarboxylic acid complete esters include dimethyl fumarate, diethyl fumarate, dimethyl maleate, and maleic acid. Diethyl ester and dimethyl methylene succinate and the like.

Specific examples of the alkenyl aromatic monomer include styrene, α-methylstyrene, methyl α-methylstyrene, and vinyltoluene.

Specific examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, and α-ethyl acrylonitrile.

Specific examples of the carboxylic acid unsaturated alcohol ester monomer include vinyl acetate and the like.

Specific examples of the olefin-based monomer include ethylene, propylene, butylene, and pentene.

In the monomer for copolymerization, a monomer having a functional group may be used in order to effectively carry out crosslinking between the internal groups of the copolymer or the copolymer.

The functional group here may, for example, be an organic acid group, a hydroxyl group, an amine group, a decylamino group, a fluorenyl group or an epoxy group.

The monomer having an organic acid group is not particularly limited, and examples thereof include a monomer having an organic acid group such as a carboxyl group, an acid anhydride group or a sulfonic acid group. Further, a monomer containing a sulfenic acid group, a sulfinic acid group, a phosphoric acid group or the like may be used in addition to these.

Specific examples of the monomer having a carboxyl group include α,β-ethylenically unsaturated monocarboxylic acid, methylene succinic acid, maleic acid, and antibutene such as acrylic acid, methacrylic acid, and crotonic acid. α,β-ethylenicity such as α,β-ethylenically unsaturated polycarboxylic acid such as diacid, monomethyl methane succinate, monobutyl maleate and monopropyl fumarate Saturated polycarboxylic acid partial esters and the like. Further, a substance having a group capable of derivatizing a carboxyl group by hydrolysis or the like, such as maleic anhydride or methylene succinic anhydride, can also be used in the same manner.

Specific examples of the monomer having a sulfonic acid group include allylsulfonic acid, methallylsulfonic acid, vinylsulfonic acid, styrenesulfonic acid, acrylamide-2-methylpropanesulfonic acid, and the like. , β-unsaturated sulfonic acid and the salts thereof.

When a monomer having an organic acid group is used, the monomer unit to be introduced is 100% by mass of the (meth) acrylate copolymer resin, preferably 0.1% by mass or more and 20% by mass or less. More preferably, the polymerization is provided in an amount of 0.5% by mass or more and 15% by mass or less. When the amount of the monomer having an organic acid group is within this range, the viscosity of the polymerization system during polymerization is easily maintained in an appropriate range, and it is easy to prevent the cross-linking of the copolymer from proceeding excessively, thereby impairing the self-adsorbing foam sheet and self-adhesion. Self-adsorptivity of the adsorptive foamed laminate.

Further, the monomer unit having an organic acid group is preferably introduced into the (meth) acrylate copolymer resin by polymerization of a monomer having an organic acid group, but may be preferably a (meth) acrylate. After the formation of the copolymer resin, the organic acid group is introduced by a conventional polymer reaction.

Examples of the monomer having a hydroxyl group include a (hydroxy) hydroxyalkyl (meth) acrylate, a (hydroxy) hydroxyalkyl (meth) acrylate, and the like.

Examples of the monomer having an amine group include N,N-dimethylaminomethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and aminostyrene.

Examples of the monomer having a guanamine group include an α,β-ethylenically unsaturated phthalamide monomer such as acrylamide, methacrylamide or N,N-dimethyl acrylamide.

Examples of the monomer having an epoxy group include glycidyl (meth)acrylate and allylepoxypropyl ether.

When a monomer having a functional group other than the organic acid group is used, the amount of the monomer used is preferably 100% by mass of the (meth) acrylate copolymer resin. It is 10% by mass or less. When the amount of the functional group other than the organic acid group is 10% by mass or less, the viscosity of the polymerization system during polymerization is easily maintained in an appropriate range, and it is easy to prevent the cross-linking of the copolymer from proceeding excessively, thereby impairing the self-adsorptive foam sheet and Self-adsorptivity of self-adsorptive foamed laminates.

Further, a polyfunctional monomer having a plurality of polymerizable unsaturated bonds may be used in combination with the monomer for copolymerization. The polyfunctional monomer preferably has the unsaturated bond at the end. By using such a polyfunctional monomer, the (meth) acrylate copolymer resin can be introduced into the molecule and/or intermolecularly crosslinked to increase the cohesive force.

As the polyfunctional monomer, for example, 1,6-hexanediol di(meth)acrylate, 1,2-ethanediol di(meth)acrylate, 1,12-dodecanediol di(a) can be used. Acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate , trimethylolpropane tri (meth) acrylate, neopentyl alcohol tri (meth) acrylate, bis (trimethylolpropane) tri (meth) acrylate, neopentyl alcohol tetra (methyl) Polyfunctional (meth) acrylate such as acrylate, dipentaerythritol hexa(meth) acrylate, 2,4-bis(trichloromethyl)-6-p-methoxystyrene-5 -three Replace three And a monoethylenically unsaturated aromatic ketone such as 4-propenyl oxybenzophenone. Polyfunctional (meth) acrylates are preferred, neopentyl alcohol di (meth) acrylate, neopentyl alcohol tri (meth) acrylate and neopentyl alcohol tetra (meth) acrylate are more good. The polyfunctional monomer may be used alone or in combination of two or more.

The (meth) acrylate copolymer resin can be obtained by copolymerizing a (meth) acrylate monomer with a monomer for copolymerization. The polymerization method in the case of obtaining a (meth) acrylate copolymer resin is not particularly limited, and may be any of solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization, and may be a method other than those described above. The type and amount of the polymerization initiator, the emulsifier, the dispersant, and the like used for the polymerization are also not particularly limited. In the polymerization, the method of adding the monomer, the polymerization initiator, the emulsifier, the dispersant or the like is not particularly limited. Further, the polymerization temperature, pressure, stirring conditions, and the like are also not limited.

The state of the (meth) acrylate copolymer resin may be solid or dispersion, but if the product obtained as an emulsion or a dispersion in emulsion polymerization or dispersion polymerization is used as it is, the mixed crosslinking agent is used. From the viewpoint of the conductive compound, it is easy to handle, and it is also convenient to foam the emulsion or dispersion.

The gel fraction of the (meth) acrylate copolymer resin is preferably 70% or less, more preferably 65% or less. When the gel fraction is in this range, it is easy to produce a self-adsorptive foamed sheet and a self-adsorptive foamed laminated sheet which have an appropriate self-adhesive force and are excellent in adhesion and smoothness.

In the present invention, the gel fraction is 500 mg of a sample of an acrylate copolymer resin in 100 ml of ethyl acetate at room temperature for 3 days, and then the insoluble component is filtered through a 200 mesh metal mesh, and air-dried at room temperature for 15 hours. Thereafter, it was dried at 100 ° C for 2 hours, and the dry mass of the insoluble component was measured, and the value was obtained by the following formula.

Gel fraction (% by mass) = ((dry mass of insoluble component after ethyl acetate impregnation) / (sample mass before ethyl acetate impregnation)) × 100

 <Carbodiimide crosslinking agent>  

The carbodiimide crosslinking agent used in the present invention is not particularly limited as long as it is a compound having a carbodiimide group, but a compound having two or more carbodiimide groups in one molecule is preferably used. As the compound, a conventional carbodiimide compound can be used.

The conventional carbodiimide compound may be synthesized or a commercially available product may be used. The carbodiimide compound of the commercially available product, for example, "DICNAL HX" manufactured by DIC Corporation and "CARBODILITE" manufactured by Nisshinbo Chemical. In the case of synthesizing the carbodiimide compound, for example, a polycarbodiimide compound in which a polyisocyanate is carbodiimidated by a decarboxylation condensation reaction in the presence of a carbodiimidation catalyst can be used.

As the raw material polyisocyanate, for example, hexamethylene diisocyanate (HDI), hydrogenated dimethyl diisocyanate (H6XDI), benzodimethyl diisocyanate (XDI), 2,2,4-trimethylhexamethylene group can be used. Diisocyanate (TMHDI), 1,12-diisocyanate decane (DDI), norbornane diisocyanate (NBDI), 2,4-bis-(8-isocyanate octyl)-1,3-dioctylcyclobutane Alkane (OCDI), 4,4'-dicyclohexylmethane diisocyanate (HMDI), tetramethyl dimethyl diisocyanate (TMXDI), isophorone diisocyanate (IPDI), 2, 4, 6-three Isopropyl phenyl diisocyanate (TIDI), 4,4'-diphenylmethane diisocyanate (MDI), methyl phenyl diisocyanate (TDI), and hydrogenated methyl phenyl diisocyanate (HTDI), etc., at 0 In the range of ~200 ° C, the mixture is stirred and mixed for a predetermined period of time under a stream of an inert gas or under a bubble, and then a carbodiimide catalyst is added and stirred and mixed to synthesize.

Here, the carbodiimide catalyst is preferably an organophosphorus compound, and particularly preferably a phospholene oxide from the viewpoint of activity. Specifically, 3-methyl-1-phenyl-2-phospholene-1-oxide, 3-methyl-1-ethyl-2-phospholene-1-oxidation , 1,3-dimethyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 1-methyl-2-phosphonium Cyclopentene-1-oxide, these double bond isomers, and the like.

The carbodiimide crosslinking agent reacts with the N-methylol group in the (meth) acrylate copolymer resin by the carbodiimide group thereof, and the (meth) acrylate copolymer A crosslinked structure is formed intramolecularly or intramolecularly. The carbodiimide-based crosslinking agent is particularly excellent in a crosslinking effect at a low temperature, and is preferably a self-adsorptive foamed sheet excellent in strength and self-adsorptivity.

A crosslinking agent other than a carbodiimide crosslinking agent and a carbodiimide crosslinking agent may be used in combination (for example, polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, sorbitol polycyclic ring) Epoxy resins such as oxypropyl ether and bisphenol A polyglycidyl ether; aziridine compounds such as acetaldehyde derivatives such as aldehydes and acrolein; methyl phenyl diisocyanate and trimethylolpropane a polyfunctional isocyanate crosslinking agent such as phenyl diisocyanate or diphenylmethane triisocyanate; An oxazoline crosslinking agent; a metal salt crosslinking agent; a metal chelate crosslinking agent; and a peroxide crosslinking agent; However, it is preferred not to use a crosslinking agent which causes formaldehyde, such as an aldehyde resin such as a melamine-formaldehyde resin, a urea-formaldehyde resin or a phenol formaldehyde resin.

The amount of the carbodiimide-based crosslinking agent to be used is from 1 part by mass to 20 parts by mass, preferably from 2 parts by mass or more, based on 100 parts by mass of the (meth) acrylate copolymer resin. 15 parts by mass or less, more preferably 2.5 parts by mass or more and 10 parts by mass or less. When the amount of the carbodiimide crosslinking agent used is within this range, it has a moderate self-adsorptivity and can improve the strength of the resin after crosslinking.

 (other additives)  

The resin composition for a self-adsorptive foamed sheet of the present invention can extremely reduce the amount of formaldehyde generated without containing a formaldehyde scavenger, but may further contain a formaldehyde scavenger.

The formaldehyde scavenger which can be used in the present invention is not particularly limited as long as it can physically adsorb formaldehyde or chemically react with formaldehyde, and may be an inorganic compound or an organic compound containing a polymer.

Specific examples of the formaldehyde scavenger include hydroxylamine sulfate, hydroxylamine hydrochloride, ammonium acetate, urea, ethyl acetal, dicyandiamide, polyamidamide, and the like. a nitrogen-containing compound such as a compound or a ruthenium compound; an oxyhalide such as stabilized chlorine dioxide; a metal salt such as disodium hydrogen phosphate, zinc sulfate, calcium chloride or magnesium sulfate; and the like. Among these, from the viewpoint of easy availability, workability, and formaldehyde trapping property, a nitrogen-containing compound is preferable, and bis(hydroxylamine sulfate) is particularly preferable.

These formaldehyde scavengers may be used alone or in combination of two or more.

In order to improve the workability in the production steps of the self-adsorptive foam sheet and the self-adsorptive foam sheet, and to improve the self-adsorptive foam sheet and self-adsorption, the resin composition for a self-adsorptive foam sheet of the present invention is improved. The properties of the foamed sheet can contain various additives as needed.

The additives may, for example, be foam stabilizers, foaming aids, tackifiers, fillers, preservatives, mold inhibitors, gelling agents, flame retardants, anti-aging agents, antioxidants, pigments, dyes, and adhesion agents. And a conductive compound or the like.

As the foam stabilizer, a fatty acid ammonium ester such as ammonium octadecanoate or a sulfonic acid type anionic surfactant such as an alkylsulfonic acid succinate, a quaternary alkyl ammonium chloride, an alkyl betaine amphiphile, and a fatty acid alkanolamine can be used. Wait.

As the foaming aid, sodium lauryl sulfate, sodium alkyl diphenyl ether disulfonate, sodium polyoxyalkylene ethyl alkyl phenolate ether or the like can be used.

As the tackifier, inorganic compound fine particles such as acrylic polymer particles or fine particle cerium oxide, and a reactive inorganic compound such as magnesium oxide can be used.

As the filler, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, barium hydroxide, clay, kaolin, glass frit, or the like can be used.

As the preservative and the antifungal agent, for example, dihydroxydichlorophenylmethane, sodium pentachlorophenolate, 2,3,4,6-tetrachloro-4-(methylsulfonyl)pyridine, 2,3,5,6 can be used. -tetrachloro-4-(methylsulfonyl)pyridine, bis(tributyltin) oxide, hexahydro-1,3,5-triethyl-s-three , silver complex and zinc complexes.

The gelling agent may be an ammonium salt such as ammonium acetate, ammonium chloride or ammonium carbonate, an alkylphenol alkylene oxide adduct, polyvinyl methyl ether, polypropylene glycol, polyether polyoxymethylene, methyl cellulose, or hydroxy group. Ethyl cellulose, polyfluorene-based sensitizer, and the like.

As the flame retardant, a phosphate ester compound, a halogenated phosphate compound, ammonium polyphosphate, antimony trioxide, zinc borate, barium metaborate, ammonium hydroxide, magnesium hydroxide, a tin compound, an organophosphorus compound, or a red phosphorus system can be used. A compound, a polyfluorene-based flame retardant, or the like.

As the antioxidant, an antioxidant such as a polyphenol type, a hydroquinone type or a hindered amine type can be used.

The pigments and dyes may be, for example, titanium oxide, carbon black, iron oxide, quinacridone or the like.

For the adhesive, rosin-based resins such as gum rosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, male rosin, rosin ‧ glyceride and hydrogenated rosin ‧ glyceride can be used; terpene resin, decene Terpene resin such as phenol resin and aromatic modified terpene resin; petroleum resin such as aliphatic petroleum resin, alicyclic petroleum resin, and aromatic petroleum resin; benzomaran-indene resin Resin phenol resin; phenol resin; hydrogenated rosin ester; disproportionated rosin ester; and a compound selected from xylene resins and the like.

 2. Self-adsorptive foam sheet and self-adsorptive foamed laminated sheet  

In the self-adsorptive foamed sheet of the present invention, the foamed body of the resin composition for self-adhesive hair sheet of the present invention is molded into a sheet shape, and then crosslinked with a (meth) acrylate copolymer resin. Formed by reaction.

Moreover, the self-adsorptive foamed laminated sheet of the present invention has an adsorption layer composed of the self-adsorptive foamed sheet of the present invention and a support layer composed of a substrate.

As a specific example of the base material used for the self-adsorptive foamed laminated sheet, for example, a paper base material, a synthetic paper, a plastic sheet, or the like can be used.

Here, the paper base material may, for example, be a paper, a coated paper, a coated paper, a kraft paper, or a laminated paper of a thermoplastic resin such as polyethylene laminated on the paper base material. The synthetic paper is formed by combining a thermoplastic resin and an inorganic filler to form a surface layer.

On the other hand, as the plastic sheet, a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, polystyrene, polyvinyl chloride resin, acrylic resin, or polycarbonate resin can be used. A fluorine-based resin such as a polyamide resin or a polytetrafluoroethylene, or a mixture of the resins or a laminate.

The thickness of the support layer composed of the substrate is not particularly limited, but is usually 10 μm to 200 μm.

When a material having releasability is used as the substrate, the adsorption layer composed of the self-adsorptive foam sheet can be formed on the substrate as described later, and then the substrate is peeled off as a self-adsorptive foam sheet.

 3. Manufacturing method  

Hereinafter, a method of producing a self-adsorptive foamed sheet and a self-adsorptive foamed laminated sheet will be described.

Fig. 1 is a flow chart showing a method S10 for producing a self-adsorptive foamed sheet of the present invention (hereinafter also referred to as "the present manufacturing method S10"). As shown in Fig. 1, the manufacturing method S10 includes a resin composition producing step S1, a foaming step S2, and a sheet forming step S3 in this order. The steps are explained below.

 (Resin composition production step S1)  

The resin composition producing step S1 is a step of preparing a resin composition for an adsorbent foam sheet comprising a (meth) acrylate copolymer having an N-methylol group and having a glass transition temperature of -10 ° C or lower. 100 parts by mass of the resin and 1 to 20 parts by mass of the carbodiimide crosslinking agent.

In the resin composition preparation step S1, a (meth) acrylate copolymer resin having a N-methylol group and a glass transition temperature of -10 ° C or lower, a carbodiimide crosslinking agent, and a reaction component are required. The other components used as needed are mixed by any method, whereby a resin composition for a self-adsorptive foamed sheet can be produced. The ratio of use of each substance used in this step to each substance is as described above, and the description thereof is omitted here.

When the (meth) acrylate copolymer resin is an emulsion or a dispersion, it is easy to add a carbodiimide crosslinking agent and other components to the mixture in an aqueous dispersion or an aqueous solution. mixing.

When the (meth) acrylate copolymer resin is a solid, the mixing method is not particularly limited, and for example, it can be mixed using a roll mill, a Henschel mixer, a kneader, or the like. The mixing can be batch or continuous.

The batch type mixer may be a kneader or a mixer for high-viscosity raw materials such as a kneader, a kneader, a closed mixer, and a planetary mixer. The continuous mixer may be a mixer of a special structure such as a combination of a rotor and a screw, a Farrel type continuous kneader or a screw type. Further, a uniaxial extruder and a twin-screw extruder used for extrusion processing are exemplified. These types of extruders and kneading machines can be combined in two or more types, and the same type of machine can be used in combination.

The form of the resin composition for a self-adsorptive foamed sheet of the present invention is not particularly limited, but in the form of an emulsion or a dispersion, it is advantageous to obtain a self-adsorptive foamed sheet.

The viscosity of the emulsion or dispersion is preferably from 2,000 to 10,000 mPa s, more preferably from 3,500 to 5,500 mPa s.

 (foaming step S2)  

The foaming step S2 is a step of foaming the resin composition for a self-adsorptive foamed sheet to obtain a foam of the resin composition for a self-adsorptive foamed sheet.

In the foaming step S2, the resin composition for the self-adsorptive foamed sheet produced in the resin composition production step S1 is foamed, whereby a foam in an uncured state can be obtained. When the resin composition for a self-adsorptive foamed sheet is in the form of an emulsion or a dispersion, a foaming emulsion or a foaming dispersion can be obtained.

The foaming method usually employs mechanical foaming. The expansion ratio can be appropriately adjusted, and is usually 1.2 to 5 times, preferably 1.5 to 4 times. The method of mechanical foaming is not particularly limited, and it can be carried out by continuous or batchwise stirring by means of an Oakes mixer and a stirrer in which a certain amount of air is mixed in the emulsion of the resin composition. The foaming emulsion thus obtained was in the form of a cream.

Further, instead of the mechanical foaming, a heat-expandable microcapsule containing a low-boiling hydrocarbon compound may be added to the acrylic resin emulsion by, for example, using a suitable synthetic resin such as a dichloroethylene copolymer or the like as a shell wall. A foamable resin composition is prepared by a method of a butadiene-based synthetic rubber emulsion or the like.

 (Slice step S3)  

The sheet forming step S3 is a step of subjecting the foam to a sheet shape and then performing a crosslinking reaction of the (meth) acrylate copolymer resin.

In the sheet forming step S3, the method of forming the foam into a sheet shape is not particularly limited. A suitable method is, for example, a method of applying the foam onto an engineering paper such as a polyester film to form a sheet.

As a method of coating the foam on the engineering paper, a conventional coating device such as a roll coater, a reverse roll coater, a screen coater, a knife coater, and a comma knife coater can be used, in particular, a doctor blade coating method is used. A uniform coating thickness can be obtained.

After the foam is formed into a sheet shape as described above, a self-adsorptive foam sheet composed of a sheet-like foam solidified can be formed on the engineering paper by performing a crosslinking reaction of the (meth) acrylate copolymer resin. . At this time, if a material having releasability is used as the engineering paper, the self-adsorptive foamed sheet can be easily separated from the engineering paper.

When the self-adsorptive foamed laminated sheet is produced, by using the above-mentioned base material as an engineering paper, in the sheet forming step S3, a self-adsorptive foamed laminated sheet can be formed on the substrate to produce a self-adsorptive property. A self-adsorptive foamed laminate sheet of an adsorption layer composed of a foam sheet and a support layer composed of a substrate.

In the sheet formation step S3, when the crosslinking reaction of the (meth) acrylate copolymer resin is carried out, it is preferred to carry out heat drying. The method of heating and drying is not particularly limited as long as it is a method of drying and crosslinking the foaming emulsion applied on the engineering paper, and a usual hot air circulation type oven, a hot oil circulation hot air chamber, and a far infrared heating room can be used. The drying temperature is preferably 60 ° C to 180 ° C, and the drying conditions can be appropriately selected depending on the properties of the emulsion, the coating amount, the coating thickness, and the like. The drying is not carried out at a constant temperature, and it is preferably carried out at a low temperature from the inside at a low temperature and at a later stage in a multi-stage drying method in which the drying is carried out at a relatively high temperature.

The density, thickness, hardness, and the like of the self-adsorbing foamed sheet are adjusted by the bubble mixing ratio, the composition of the resin composition for the self-adsorptive foamed sheet, the solid content concentration, and the conditions of heat drying and solidification. The thickness of the self-adsorptive foam sheet is preferably 0.03 to 3 mm, more preferably 0.05 to 1 mm, and particularly preferably 0.05 to 0.5 mm. When the thickness is less than 0.03 mm, when the self-adsorptive foamed sheet of the present invention is used as an article holding material and an article surface protective material, impact absorption is poor, and the article holding power and the surface protection function of the article are insufficient, and if it is thicker than 3 mm, The strength of the self-adsorptive foamed sheet is also poor, which is also poor. The density of the self-adsorptive foamed sheet is not particularly limited, and is preferably from 0.1 to 1.0 g/cm ³ from the viewpoint of impact absorbability.

The self-adsorptive foamed sheet or the self-adsorptive foamed laminated sheet obtained by the sheet forming step S3 is usually wound on a coiler after being attached to the surface having a self-adsorptive property, and is cut by pressurization. Cutting and cutting machines are cut into easy-to-use sizes.

 4. Use  

The self-adsorptive foamed laminated sheet of the present invention can be printed on the substrate surface by, for example, offset printing, sticker printing, flexographic printing, stencil printing, gravure printing, laser printing, thermal transfer printing, and ink jet printing. Wait to implement printing.

A printed self-adsorptive foamed laminated sheet is applied to the surface of the substrate, and can be used as a decorative material for construction, a decorative material for advertising, and a material for stationery or toys. For example, it can be used as a promotional kanban, commonly known as POP billboards (posters, stickers and displays, etc.), mats (tableware, table mats, stationery, etc.), burgers, sushi and fried noodles, etc. menus, catalogs, panels , Kanban (instead of metal plates), photo paper, store price list, guide board (store guide, direction, destination guide, desserts, food, etc.), gardening POP (insert labels, etc.), road indicators (burial ‧ Residential display halls, etc., notice boards (no entry and forest road work, etc.), calendars (with images), simple whiteboards, mouse pads, coasters, alternative prints for label printers, and adhesive labels.

Moreover, the self-adsorptive foamed sheet and the self-adsorptive foamed laminated sheet of the present invention are excellent in peelability, and a part of the self-adsorptive foamed sheet does not remain on the side of the attached article after peeling. Therefore, it can be applied to various object surface protection materials and article holding materials for optical members, precision members, and the like.

The self-adsorptive foamed sheet and the self-adsorptive foamed laminated sheet of the present invention have a very small amount even if formaldehyde is generated, and the amount of formaldehyde generated can be made by appropriately setting the composition of the resin composition for the self-adsorptive foamed sheet. Less than the detection limit (eg less than 0.1ppm). Therefore, it is suitable for use in places and uses where formaldehyde is prohibited or unsuitable. In other words, the self-adsorptive foamed sheet and the self-adsorptive foamed laminated sheet of the present invention are suitably used as a building interior material and a material for stationery or toys.

Example

Hereinafter, the present invention will be described in further detail by way of examples, but the invention is not limited to the examples. In addition, the "parts" and "%" used herein are based on quality unless otherwise specified.

 [Material characteristics]    <Measurement of glass transition temperature (Tg) of acrylate copolymer resin>  

The glass transition temperature (Tg) of the acrylate copolymer resin used as the self-adsorptive foamed laminate sheet material described later was measured by the following method. The acrylate copolymer resin was coated on a polyethylene terephthalate film having a thickness of 50 μm with a 250 μm sprayer, and dried at room temperature for 24 hours to obtain a resin film. This film was used as a sample, and the glass transition temperature (° C.) was measured using a differential scanning calorimeter (DSC6220, manufactured by SII NanoTechnology Co., Ltd.) in accordance with JIS K 7121 at a measurement temperature of -50 ° C to 160 ° C and a temperature increase rate of 10 ° C /min. The results are shown in Table 1.

 <Measurement of Gel Fraction of Acrylate Copolymer Resin>  

The gel fraction of the acrylate copolymer resin used in the self-adsorptive foamed laminated sheet produced as described later was measured by the following method. The acrylate copolymer resin was coated on a polyethylene terephthalate film having a thickness of 50 μm with a 250 μm sprayer, and dried at room temperature for 24 hours to obtain a resin film. The film was used as a sample, and the amount (X) (about 500 mg) was precisely weighed, and it was immersed in 100 ml of ethyl acetate at room temperature for 3 days, and then the insoluble component was filtered through a metal mesh of 200 mesh, and air-dried at normal temperature for 15 hours. Thereafter, the mixture was dried at 100 ° C for 2 hours, and after cooling at room temperature, the mass (Y) of the sample was measured. The gel fraction was calculated by substituting X and Y into the following formula. The results are shown in Table 1.

Gel fraction (%) = (Y) / (X) × 100

 [evaluation items]    <Self-adsorption force>  

After the self-adsorptive foamed laminated sheet was produced as described later, a test piece having a size of 125 mm × 25 mm was cut out for use. The glass plate of the smooth surface was bonded to the adsorption surface of the test piece, and the test piece was pressed with a 2 kgf load roller, and then placed in a 23 ° C, 50% RH environment for 1 hour. Thereafter, the end portion of the test piece was fixed to the upper chuck of Autograph (AG-IS, manufactured by Shimadzu Corporation), and the glass plate was fixed to the lower chuck at 300 ° C in a 50 ° RH environment at 23 ° C. The speed was subjected to a 180 degree peel test. The test force at this time is the self-adsorption force (N/cm). The results are shown in Table 1. If the result of the evaluation is 0.01 to 1 N/cm, it is said to have an appropriate self-adsorption force.

 <Formaldehyde release evaluation>  

The self-adsorptive foamed laminated sheet was produced as described later, and after further separating the separator film on the surface of the adsorbing layer, a test piece having a size of 200 mm × 200 mm was cut out for use. The test piece was placed in a 5 L volume Tedlar bag and sealed. Air of 2 L was sealed therein, and the mixture was allowed to stand in a thermostat set at 23 ° C and 50% RH for 6 hours, and then the concentration of formaldehyde in the bag was measured with a detecting tube (manufactured by GASTEC Co., Ltd., No. 91L). The formaldehyde concentration of 0.2 ppm or less is indicated by "○", and when it is more than 0.2 ppm, it is "x". The results are shown in Table 1.

 <Evaluation of Adhesion between Adsorption Layer and Substrate>  

After the self-adsorptive foamed laminated sheet was produced as described later, a test piece having a size of 125 mm × 25 mm was cut out for use. The tape was applied to the surface of the adsorption layer of the test piece in such a manner as to retain the respective end portions. The end portion of the tape which is not attached to the test piece is fixed to the upper chuck of Autograph (AG-IS, manufactured by Shimadzu Corporation), and the end portion of the test piece is fixed to the lower chuck at 23 ° C, 50% RH environment. Next, the T-peel test was carried out at a speed of 300 mm/min. The peeling form was indicated as "○" when the cohesive failure of the adsorption layer, and the interface between the substrate and the adsorption layer was "x". The results are shown in Table 1.

 <Gloss (60° gloss)>  

The glossiness of the surface of the adsorption layer was measured in accordance with JIS Z 8741 using a gloss meter (manufactured by Tokyo Denshoku Co., Ltd., GP-60A). The results are shown in Table 1. If the result of the evaluation is 35 or more, the smoothness of the surface of the sheet is excellent.

 [Production of self-adsorptive foamed laminate]    (Example 1)  

In the mixing vessel, an acrylate copolymer resin (I) having an N-methylol group was added in an amount of 100 parts by solid content (composition: ethyl acrylate 46.9% / butyl acrylate 45.8% / acrylonitrile 5.9%) /N-hydroxymethyl acrylamide 1.4% copolymer resin, glass transition temperature: -25.9 ° C, gel fraction: 43.1%) aqueous dispersion (solid content 55%), solid content converted to 3.6 parts The carbodiimide-based crosslinking agent (DICNAL HX, manufactured by DIC Corporation) and the titanium oxide aqueous dispersion (DISPERSE WHITE HG-701, manufactured by DIC Corporation) having a solid content of 4.2 parts were stirred by a disperser. Then, stirring was continued, and a viscosity-increasing agent (carboxylic acid-modified acrylate copolymer, Aron B-300K, manufactured by Toagosei Co., Ltd.) and a solid foaming agent in terms of solid content were added in this order. Alkyl betaine amphoteric ‧ fatty acid alkanoguanamine mixture (DICNAL M-20, manufactured by DIC Corporation) / sulfonic acid type anionic surfactant (1/1 mixture of DICNAL M-40), to 150 Mesh filtering. Finally, ammonia was added to adjust the viscosity to 4,500 mPa·s to obtain a foamable resin composition.

The foamable resin composition was stirred by a foamer, foamed at a foaming ratio of 2 times, and further stirred at a stirring speed for 5 minutes.

The obtained foaming mixture was coated on a substrate (polyethylene terephthalate film having a thickness of 50 μm) using a sprayer of 0.3 mm. This was placed in a drying oven, maintained at 80 ° C for 1.33 minutes, maintained at 120 ° C for 1.33 minutes, maintained at 140 ° C for 1.33 minutes, and dried and crosslinked to laminate an adsorption layer (self-adsorbing foam sheet) on the substrate to obtain an example. A self-adsorptive foamed laminate.

 (Example 2)  

In addition to the carbodiimide-based crosslinking agent (CARBODILITE (registered trademark) E-02, manufactured by Nisshinbo Chemical Co., Ltd.), in place of the carbodiimide crosslinking agent (DICNAL HX, manufactured by DIC Corporation) used in Example 1, In the same manner as in Example 1, the sheet of Example 2 was produced.

 (Example 3)  

The N-hydroxymethyl group-containing acrylate copolymer resin (II) having the composition changed to a glass transition temperature of -17.6 ° C and a gel fraction of 28.0% was used instead of the N-hydroxymethyl group used in Example 1. A sheet of Example 3 was produced in the same manner as in Example 1 except for the acrylate copolymer resin (I).

 (Example 4)  

The N-hydroxymethyl group-containing acrylate copolymer resin (III) having the composition changed to a glass transition temperature of -10.1 ° C and a gel fraction of 42.2% was used instead of the N-hydroxymethyl group used in Example 1. A sheet of Example 4 was produced in the same manner as in Example 1 except for the acrylate copolymer resin (I).

 (Example 5)  

The N-hydroxymethyl group-containing acrylate copolymer resin (IV) having the composition changed to a glass transition temperature of -15.3 ° C and a gel fraction of 41.5% was used instead of the N-hydroxymethyl group used in Example 1. A sheet of Example 5 was produced in the same manner as in Example 1 except for the acrylate copolymer resin (I).

 (Example 6)  

The N-hydroxymethyl group-containing acrylate copolymer resin (V) having the composition changed to a glass transition temperature of -22.8 ° C and a gel fraction of 60.5% was used instead of the N-hydroxymethyl group used in Example 1. A sheet of Example 6 was produced in the same manner as in Example 1 except for the acrylate copolymer resin (I).

 (Comparative Example 1)  

In place of the melamine-based crosslinking agent (BECKAMINE M3, manufactured by DIC Corporation) and the crosslinking accelerator (CATALYST ACX, manufactured by DIC Corporation), instead of the carbodiimide crosslinking agent used in Example 1, DICNAL HX, manufactured by DIC Corporation The sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that the procedure of Example 1 was carried out.

 (Comparative Example 2)  

In addition to the use of a carboxyl group-containing acrylate copolymer resin (I') (composition: ethyl acrylate 49.0% / butyl acrylate 42.1% / acrylonitrile 6.9% / acrylic acid 2.0% of the copolymer resin, glass transition temperature: -20.9 °C, gel fraction: 89.6%) A sheet of Comparative Example 2 was produced in the same manner as in Example 1 except that the N-hydroxymethyl group-containing acrylate copolymer resin (I) used in Example 1 was used.

 (Comparative Example 3)  

The carboxyl group-containing acrylate copolymer resin (II') was changed to a composition having a carboxyl group-containing acrylate copolymer resin (I') in Comparative Example 1 and having a glass transition temperature of 6.2 ° C and a gel fraction of 65.4%. A sheet of Comparative Example 3 was produced in the same manner as in Example 1 except that the N-hydroxymethyl group-containing acrylate copolymer resin (I) used in Example 1 was used.

As shown in Table 1, the sheets of Examples 1 to 6 all had a low formaldehyde release amount, had a moderate self-adsorption force, and were excellent in adhesion and smoothness. On the one hand, the sheet of Comparative Example 1 using a melamine-based crosslinking agent had a poor result in evaluation of formaldehyde emission. Further, the sheet of Comparative Example 2 using a high gel fraction acrylate copolymer resin containing a carboxyl group and not containing N-hydroxymethyl group was inferior in adhesion and smoothness. Further, the sheet of Comparative Example 3 using a carboxyl group-containing acrylate copolymer resin having a high glass transition temperature was not attached to a glass plate in the measurement test for self-adsorption force, and the adhesion and smoothness were also inferior.

Claims (10)

 A resin composition for a self-adsulating foamed sheet comprising: 100 parts by mass of a (meth) acrylate copolymer resin having an N-methylol group and having a glass transition temperature of -10 ° C or lower; and a carbodiimide The crosslinking agent is 1 to 20 parts by mass.    The resin composition for self-adsorbing foam sheets according to claim 1, wherein the (meth) acrylate copolymer resin has a gel fraction of 70% or less.    A self-adsulating foamed sheet which is formed by forming a foamed foamed body of a self-adsulating foamed sheet of the claim 1 or 2 into a sheet form, and then performing the (meth) acrylate copolymerization. The resin is formed by a crosslinking reaction.    A self-adsorptive foamed laminated sheet comprising an adsorption layer composed of the self-adsorptive foamed sheet of claim 3 and a support layer composed of a substrate.    The self-adsorptive foamed laminated sheet according to claim 4, wherein the substrate is a resin film.    A method for producing a self-adsulating foam sheet, comprising the steps of: preparing a resin composition for a self-adsulating foam sheet comprising a N-methylol group and having a glass transition temperature of -10 ° C or lower (methyl group) 100 parts by mass of the acrylate copolymer resin and 1 to 20 parts by mass of the carbodiimide crosslinking agent; and the resin composition for the self-adsorptive foam sheet is foamed to obtain the resin for the self-adsorptive foam sheet a step of forming a foam of the composition; and after the foam is formed into a sheet shape, a step of crosslinking the (meth) acrylate copolymer resin is carried out.    The method for producing a self-adsulating foam sheet according to claim 6, wherein the (meth) acrylate copolymer resin has a gel fraction of 70% or less.    A method for producing a self-adsorptive foamed laminated sheet, which comprises a method for producing a self-adsorptive foamed laminated sheet comprising an adsorbing layer composed of a self-adsorbing foam sheet and a support layer composed of a substrate, comprising the steps of: A step of preparing a resin composition for a self-adsulating foamed sheet comprising 100 parts by mass of a (meth) acrylate copolymer resin having an N-methylol group and having a glass transition temperature of -10 ° C or lower and a carbodiimide 1 to 20 parts by mass of a crosslinking agent; a step of foaming the self-adsorptive foam sheet with a resin composition to obtain a foam of the resin composition for a self-adsorptive foam sheet; and on the substrate, After the foam is formed into a sheet shape, the adsorption layer is laminated on the support layer by performing a crosslinking reaction of the (meth) acrylate copolymer resin.    The method for producing a self-adsorptive foamed laminated sheet according to claim 8, wherein the (meth) acrylate copolymer resin has a gel fraction of 70% or less.    The method for producing a self-adsorptive foamed laminated sheet according to claim 9, wherein the substrate is a resin film.