JP2006122915A - Two liquid type acrylic adhesive for manufacturing pattern of casting mold, and bonding method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acrylic adhesive to be used for joining components composing a disappearable casting pattern made of methacrylic resin foamed body, which acrylic adhesive (1) can reduce the generation of burnt dregs of the hardened adhesive, (2) is low in the solubility for the methacrylic resin foamed body, (3) can firmly join the components of the pattern, and (4) can join the components of the pattern in a short period of time. <P>SOLUTION: The two liquid type acrylic adhesive contains (A) a polymeric monomer, (B) an organic peroxide, (C) a vanadium compound, and (D) an acidic phosphoric acid compound, wherein 80 mass% or more of (A) is a (meth)acrylate having a specified molecular structure and molecular weight. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an acrylic adhesive having a methacrylic resin foam as an adherend. More specifically, the present invention relates to an adhesive used for manufacturing a disappearance model for casting made of a methacrylic resin foam.
Moreover, this invention relates to the method of manufacturing the vanishing model for casting using this adhesive agent.

  Known casting methods for producing castings include a wooden mold method, a disappearance model casting method (also called a full mold casting method or a lost foam method), and a shrink mold method. The vanishing model casting method is a molten metal (for example, molten cast steel) in a casting mold in which a vanishing model for casting using a synthetic resin foam as a base material is manufactured, and the vanishing model for casting is embedded in casting sand. Pour molten metal. By casting the lost model for casting with the molten metal and replacing it with the molten metal, a casting having a shape according to the model is manufactured. The vanishing model casting method has been widespread rapidly since the 1960s because it is economical and convenient.

If the structure of the casting disappearance model is complicated,
1) Produce a plurality of model parts that constitute the target casting disappearance model,
2) Manufactured by joining the produced model parts together with an adhesive.

  A typical example of the synthetic resin foam that is the base material of the casting disappearance model is polystyrene foam (EPS). When a casting disappearance model based on polystyrene foam is burned (for example, embedded in foundry sand, molten metal is poured and burned), there is a tendency that a relatively large amount of combustion residue is generated. This is presumably because the combustion residue of polystyrene, which is a component of the polystyrene foam, is relatively large.

When there are many combustion residues of the casting disappearance model, the combustion residues are likely to enter the inside of the metal of the casting manufactured using the casting disappearance model or adhere to the surface. If the combustion residue enters the inside of the casting or adheres to the surface, the strength of the casting is reduced or the workability is deteriorated.
Therefore, the production of combustion residues has been a problem particularly in the production of castings that require high precision, such as automobile and ship engines and precision machine tools.

In order to reduce the combustion residue of the casting disappearance model, it is also necessary to reduce the combustion residue of the synthetic resin foam that is the base material. It is also important to reduce the combustion residue of the adhesive used to join certain model parts. However, since there are many combustion residues of typical polystyrene foam itself as a base material for the disappearance model for casting, the combustion residue of the adhesive has not been studied much.
As a prior art for examining the combustion residue of an adhesive used for joining model parts constituting a casting disappearance model, an EVA (ethylene-vinyl lactate-copolymer) hot melt adhesive added with an acetal resin powder is used. Is only proposed (see Patent Document 1).
Therefore, in the production of casting disappearance model, as an adhesive for joining the model parts that compose it, adhesives that are easy to use, such as two-part epoxy, one-part urethane, urea, etc. Agents have been used.

However, adhesives such as two-part epoxy, one-part urethane, and urea are slow in curing speed, and thus require a long time to develop adhesive strength. Therefore, it is necessary to stand for a long time until the obtained bonded product (one obtained by bonding model parts) is used in the next step, and a long time is required for manufacturing a lost model for casting.
In addition, since the two-part epoxy adhesive has a curing reaction that proceeds by an addition polymerization reaction, it is essential that the two parts are mixed well. If the mixing is not sufficient, the adhesive strength is not improved. It was. One-component urethane adhesives and urea adhesives have a problem that their curing speed is slower than that of epoxy adhesives and their adhesive strength is slightly weaker.
Japanese Patent Laid-Open No. 05-212491

The present invention has been made in view of such a situation. As described above, the polystyrene foam that has been mainly used as the base material for the casting disappearance model has a relatively large amount of combustion residue, and is not always satisfactory as the base material for the disappearance model for casting.
On the other hand, in recent years, a methacrylic resin foam (Japanese Patent Laid-Open No. 2001-233986) suitable as a base material for a casting disappearance model has been reported. It was found that the combustion residue of the methacrylic resin foam was about 0.01 with respect to the combustion residue 1.0 of the polystyrene foam, and was significantly reduced. This is presumably because the methacrylic polymer has many oxygen atoms in its molecule.

    Thus, it was found that the methacrylic resin is useful as a base material for the casting disappearance model in that the combustion residue is very small. Therefore, the present inventor has focused attention on the combustion residue of the adhesive for joining the model parts used in the production of the casting disappearance model, which has not been attracting much attention. And it came to search for the adhesive agent with few generation | occurrence | production of combustion residues as much as possible.

First, the present inventor analyzed the amount of combustion residues of various adhesives themselves. In other words, combustion of two-part epoxy adhesive, one-part urethane adhesive, and urea adhesive, which are conventional representative adhesives that have been used to join model parts that make up the casting disappearance model The residue was determined. Specifically, the cured products of various adhesives are heated from 20 ° C. to 800 ° C. at a heating rate of 10 ° C./min in an argon atmosphere, and then the weight of the remaining residue is determined to determine the combustion residue. The amount. For comparison, the amount of combustion residue of polystyrene foam was also determined in the same manner.
As a result, when the combustion residue of polystyrene foam is 1.0, the combustion residue of the two-component epoxy adhesive is 9.0, the combustion residue of the one-component urethane adhesive is 5.2, and the urea adhesive The combustion residue of 17.9 was 17.9, and it was found that the combustion residue of any adhesive was much more than that of polystyrene foam.

Here, the amount of the combustion residue was measured as follows.
In accordance with JIS K7120, the cured product of each adhesive (in the case of two-component adhesive, the cured product obtained by mixing the two liquids in equal mass) in a constant temperature and humidity room at 23 ° C and 50% RH. Then, differential thermal analysis was performed under the following conditions, and the weight of the combustion residue was measured.
Measuring instrument: Seiko Electronics Co., Ltd. TG / DTA220
Sample: Measured at 10 mg in an open sample container made of 5φ platinum Measurement temperature: 20 to 800 ° C., temperature rising speed = 10 ° C./min, measurement completed when reaching 800 ° C. Argon flow: 300 ml / min

It was estimated that the main component of the adhesive has nitrogen atoms that are less flammable than carbon atoms and hydrogen atoms in the molecule as a cause of the large number of combustion residues of these adhesives. Therefore, the present inventors paid attention to a two-component acrylic adhesive mainly composed of a polymerizable (meth) acrylate having many oxygen atoms based on an ester group in the molecule. The amount of combustion residue was measured in the same manner as described above. As a result, when the combustion residue of the polystyrene foam is 1.0, the combustion residue of the two-component acrylic adhesive is 1.3 to 3.5, which is compared with the above-mentioned conventionally used adhesives. And found that the combustion residue is remarkably small.

As described above, it has been found that the two-component acrylic adhesive is advantageous in that the amount of combustion residue generated is suppressed. It is also known that a two-part acrylic adhesive is fast-curing and can provide good adhesion even with rough mixing.
However, the polymerizable (meth) acrylate contained in the conventional two-component acrylic adhesive has a property of dissolving the methacrylic resin foam (hereinafter, this property is also referred to as “solubility in methacrylic resin foam”). strong. Therefore, when a conventional acrylic adhesive is applied to a model part constituting a disappearance model for casting made of methacrylic resin foam, the model part is dissolved before being cured, and the produced casting It is easy to create a gap in the disappearing model and change the model size. Furthermore, there is a problem that sufficient adhesive strength cannot be obtained.

From these facts, in the production of the disappearance model for casting made of methacrylic resin foam, the present invention is an adhesive suitably used for joining the model parts constituting it, that is,
1) Generation of combustion residue of the cured product has been reduced,
2) The property of dissolving methacrylic resin foam is weak,
3) It is an object to provide an acrylic adhesive characterized in that a model part can be strongly bonded, and 4) a model part can be bonded in a short time.
It is another object of the present invention to provide a method for producing a casting disappearance model easily and in a short time using this acrylic adhesive.

  As a result of earnest research, the present inventor, as a at least part of the polymerizable (meth) acrylate, in a two-part acrylic adhesive containing a polymerizable (meth) acrylate, an organic peroxide, and a radical generation accelerator, It has been found that the above-mentioned problems can be solved by using a specific polymerizable (meth) acrylate, and the present invention has been completed. That is, the present invention is as follows.

[1] It contains (A) a polymerizable monomer, (B) an organic peroxide, (C) a vanadium compound, and (D) an acidic phosphoric acid compound so that (B) and (C) do not coexist. An acrylic adhesive that is stored in two parts,
Manufacture disappearance model for casting made of methacrylic resin foam in which 80% by mass or more of (A) is one or more (meth) acrylates selected from the group consisting of (i) to (ri) below. A two-component acrylic adhesive.

(A) Aliphatic (meth) acrylate having a molecular weight of 125 or more (b) Carboxyl group-containing (meth) acrylate having a molecular weight of 140 or more (c) Hydroxyl group-containing (meth) acrylate having a molecular weight of 145 or more (d) Molecular weight of 230 or more Polyester (meth) acrylate (e) Phenoxyalkylene oxide-modified (meth) acrylate having a molecular weight of 210 or more (f) Alkoxyalkylene oxide-modified (meth) acrylate having a molecular weight of 450 or more (g) Bisphenol A or bisphenol having a molecular weight of 460 or more F alkylene oxide-modified (meth) acrylate (h) Polyalkylene glycol-modified (meth) acrylate having a molecular weight of 305 or more (i) Other (meth) acrylate having a molecular weight of 600 or more

[2] The acrylic adhesive according to [1], wherein one of the two agents is placed on a smooth surface of a methacrylic resin foam in a constant temperature and humidity chamber at 23 ° C. and 50% RH. An adhesive, characterized in that the depth of a depression formed in a methacrylic resin foam when applied 1 g / cm ² and wiped off the applied agent after 10 minutes is 0.2 mm or less.

[3] Mass of combustion residue (combustion condition: 800 ° C. under argon atmosphere) of the acrylic adhesive according to [1], which is cured in a constant temperature and humidity chamber of 23 ° C .; 50% RH Is 4% or less of the mass of the cured product before combustion.

[4] A casting disappearance model made of methacrylic resin foam, including a step of bonding the joint surfaces of the model part 1 and the model part 2 constituting the disappearance model for casting made of methacrylic resin foam to each other. A method of manufacturing comprising:
The pasting step includes
(A) The process of apply | coating one of the two agents of the acrylic adhesive as described in [1] to the joint surface of the model component 1,
(B) a step of applying the other of the two adhesives of the acrylic adhesive described in [1] to the joint surface of the model component 2, and (c) the joint surface of the model component 1 and the model component A method comprising a step of bonding the two bonding surfaces together.

[5] A disappearance model for casting made of methacrylic resin foam, including a step of bonding the joint surfaces of the model part 1 and the model part 2 constituting the disappearance model for casting made of methacrylic resin foam to each other. A method of manufacturing comprising:
The step of bonding the joint surfaces includes
(A) applying both of the two adhesives according to [1] to the joint surface of the model component 1; and (b) pasting the joint surface of the model component 1 and the joint surface of the model component 2 together. A method comprising a step of combining.

ADVANTAGE OF THE INVENTION According to this invention, the acrylic adhesive with which it was hard to melt | dissolve a methacrylic resin foam, and sclerosis | hardenability improved is provided. By using this adhesive, it is a casting model with high precision and a disappearance model for casting based on a methacrylic resin foam with reduced smoke and combustion residue when burned. be able to.
Further, by using the method provided by the present invention, the casting disappearance model can be easily produced in a short time.

<Acrylic adhesive of the present invention>
The acrylic adhesive of the present invention comprises a component (A) composed of a polymerizable monomer, a component (B) composed of an organic peroxide, a component (C) composed of a vanadium compound, and an acidic phosphate compound (D ) Component as an essential component, but any other component such as a curing accelerator or a polymerization inhibitor may also be included.

The component (A) composed of the polymerizable monomer includes a polymerizable acrylate and / or a polymerizable methacrylate (hereinafter, both are collectively referred to as “polymerizable (meth) acrylate”). (
The polymerizable (meth) acrylate contained in the component A) may be one type, but may be a combination of two or more types.

The component (A) preferably has weak or substantially no property of dissolving the methacrylic resin foam. Therefore, 80% by mass or more of component (A), preferably 90% by mass or more, more preferably about 100% by mass is selected from 1 or 2 or more selected from the (meth) acrylates described in (i) to (ri) above. It is preferable that it is the combination of these.
When the content is less than 80% by mass, the adhesive of the present invention containing the component (A) may dissolve the methacrylic resin foam, and thus the effects of the present invention may be impaired.

In addition, "(meth) acrylate selected from (meth) acrylates described in (i) to (ri)" is (meth) acrylate corresponding to any group of (i) to (ri) Good.
That is, for example, a (meth) acrylate having a molecular weight of 300, which is a phenoxyalkylene oxide-modified (meth) acrylate and also a polyalkylene glycol-modified (meth) acrylate, does not fall under (h), but (e) Since it corresponds, it is contained in the (meth) acrylate chosen from (i)-(li).

As above-mentioned, it is preferable that 80 mass% or more of (A) component is a 1 or 2 or more combination chosen from the (meth) acrylate as described in (i)-(ri).
As "one or two or more combinations selected from (meth) acrylates described in (i) to (ri)", (g) alone; (h) alone; (g) and / or (h) And a combination of one or more of (b), (c) and (d).

(I) Aliphatic (meth) acrylate having a molecular weight of 125 or more An aliphatic (meth) acrylate is a (meth) acrylic acid ester represented by CH ₂ ═C (—R) COOX (R = H or Me). And X is an aliphatic group. Here, the aliphatic group X is preferably an aliphatic hydrocarbon group, which may be either saturated or unsaturated, but is preferably saturated (thus, X is more preferably an alkyl group). Further, the aliphatic group X may be either a chain (may be linear or branched) or cyclic.
For example, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, alkyl (meth) acrylate such as cetyl (meth) acrylate; isobornyl (meth) acrylate, dicyclo Examples thereof include alicyclic (meth) acrylates such as pentenyl (meth) acrylate and tricyclodecanyl (meth) acrylate; trimethylolpropane tri (meth) acrylate, neopentyl glycol di (meth) acrylate and the like.
Among them, lauryl (meth) acrylate, cetyl (meth) acrylate, trimethylolpropane tri (meth) acrylate and the like having a molecular weight of 240 or more impart good curability and adhesiveness with the adhesive of the present invention. Is preferable.

(B) Carboxyl group-containing (meth) acrylate having a molecular weight of 140 or more The carboxyl group-containing (meth) acrylate is (meth) acrylic represented by CH ₂ ═C (—R) COOX (R = H or Me). An acid ester in which X is a group having a carboxyl group (—COOH). More preferably, the compound represented by a following formula is mentioned.

  Examples include acrylic acid dimer, 2- (meth) acryloyloxyethyl succinate, 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl hexahydrophthalate, and the like. Of these, 2- (meth) acryloyloxyethyl succinate having a molecular weight of 200 or more is preferred.

(C) Hydroxyl group-containing (meth) acrylate having a molecular weight of 145 or more Hydroxyl group-containing (meth) acrylate is a (meth) acrylic acid ester represented by CH ₂ ═C (—R) COOX (R = H or Me). And X is a group having a hydroxyl group (—OH).
For example, epoxy (meth) acrylates such as hydroxybutyl (meth) acrylate, glycerin di (meth) acrylate, 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate, and 2-hydroxy-3-phenoxypropyl (meth) acrylate Is mentioned.
Among them, epoxy (meth) acrylates such as glycerin di (meth) acrylate, 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate, and 2-hydroxy-3-phenoxypropyl (meth) acrylate having a molecular weight of 200 or more. Etc. are preferable because good curability and adhesiveness can be imparted by the adhesive of the present invention.

(D) Polyester (meth) acrylate having a molecular weight of 230 or more Polyester (meth) acrylate is obtained by condensation reaction of one or both of terminal hydroxyl groups of polyester with (meth) acrylic acid. Preferred examples of the polyester include polycaprolactone (HO— [CO (CH ₂ ) ₅ O] _n —H), bispolyethylene glycol phthalate, and the like.
Specific examples include ω-carboxypolycaprolactone mono (meth) acrylate and bispolyethylene glycol phthalate di (meth) acrylate. Among them, ω-carboxypolycaprolactone (n = 2 or more) mono (meth) acrylate, bispolyethyleneglycol phthalate di (meth) acrylate, etc., having a molecular weight of 300 or more, have better curability in the adhesive of the present invention. Further, it is preferable because adhesion can be imparted.

(E) Phenoxyalkylene oxide-modified (meth) acrylate having a molecular weight of 210 or more Phenoxyalkylene oxide-modified (meth) acrylate is a condensation of the terminal hydroxy group of phenoxyalkylene oxide or phenoxy (poly) alkylene oxide with (meth) acrylic acid. It has been reacted. An arbitrary substituent (preferably an alkyl group such as a nonyl group or a cumyl group) may be present on the phenyl ring of the phenoxy group of the phenoxyalkylene oxide-modified (meth) acrylate. An example of phenoxyalkylene oxide is phenoxypolyethylene oxide.
Specific examples of (e) include substituted or unsubstituted phenoxypolyethylene oxide-modified (meth) acrylates represented by the following formula. Examples of the substituted phenoxypolyethylene oxide-modified (meth) acrylate include nonylphenoxypolyethylene oxide-modified (meth) acrylate and cumyl (preferably p-cumyl) phenoxyethylene oxide-modified (meth) acrylate.
Among them, phenoxypolyethylene oxide (n = 4 or more) modified (meth) acrylate having a molecular weight of 325 or more, nonylphenol polyethylene oxide (n = 4 or more) modified (meth) acrylate, etc. are better for the adhesive of the present invention. It is preferable because it can provide high curability and adhesiveness.

(F) Alkoxyalkylene oxide-modified (meth) acrylate having a molecular weight of 450 or more With alkoxyalkylene oxide-modified (meth) acrylate, the terminal hydroxy group of alkoxyalkylene oxide or alkoxypolyalkylene oxide is condensed with (meth) acrylic acid. It is a thing. As alkoxy, methoxy or ethoxy is preferably exemplified.
Examples thereof include alkoxy (preferably methoxy) polyethylene glycol mono (meth) acrylate represented by the following formula.

(G) Alkylene oxide-modified (meth) acrylate of bisphenol A or bisphenol F having a molecular weight of 460 or more The alkylene oxide-modified (meth) acrylate of bisphenol A has one or both (preferably both) hydroxyl groups of bisphenol A. Those modified with an alkylene oxide-modified (meth) acrylate.
The alkylene oxide-modified (meth) acrylate of bisphenol F is one in which one or both (preferably both) hydroxyl groups of bisphenol F are modified with alkylene oxide-modified (meth) acrylate.
Examples thereof include polyethylene oxide-modified di (meth) acrylate of bisphenol A represented by the following formula. Especially, the polyethylene oxide modified | denatured (n = 10) di (meth) acrylate of the bisphenol A whose molecular weight is 800 or more is illustrated preferably.

(H) Polyalkylene glycol-modified (meth) acrylate having a molecular weight of 305 or more Examples include polyethylene glycol di (meth) acrylate represented by the following formula, among which polyethylene having a molecular weight of 500 or more (n = 9 As described above, glycol di (meth) acrylate and the like are preferable because they can impart better curability and adhesiveness to the adhesive of the present invention.

  Examples of (meth) acrylate having a molecular weight of 600 or more include polyurethane (meth) acrylate and the like.

  Although the upper limit of the molecular weight of the (meth) acrylates (i) to (ri) is not particularly set, the molecular weight may be a molecular weight having fluidity at room temperature.

  As described above, the component (A) composed of a polymerizable monomer is preferably a combination of one or two or more of which 80% by mass or more is selected from the (meth) acrylates described in (i) to (ri). However, it may contain optional components other than (i) to (ri). As an optional component other than (i) to (ri), (meth) acrylic acid is preferably exemplified. By including such a component, good mechanical strength and adhesiveness can be imparted by the adhesive of the present invention.

  The content of the (meth) acrylic acid and the low molecular weight polymerizable (meth) acrylate having a carboxyl group in the component (A) is usually 20% by mass or less, and preferably 10% by mass or less. When it exceeds 20 mass%, the solubility with respect to the methacrylic resin foam of the adhesive agent of this invention may become strong. Accordingly, when the adhesive is applied to the methacrylic resin foam, the foam is dissolved and air contained in the foam is mixed with the adhesive. Therefore, the radical polymerization reaction of the adhesive is inhibited by the mixed air, and the curing rate may be remarkably slowed. In addition, the adhesive strength may be weakened.

The component (B) composed of the organic peroxide can act as a radical initiator in the adhesive of the present invention or as a redox polymerization initiator together with the component (C). That is, the component (B) can start the addition polymerization reaction or the curing reaction of the component (A). As the component (B), a known organic peroxide can be arbitrarily used as a radical initiator.
For example, hydroperoxides such as t-butyl hydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide; t-butyl peroxylaurate, t-butyl peroxybenzoate, t- Peroxyesters such as butyl peroxydecanoate; Peroxyketals such as 1,5-di-t-butylperoxy-3,3,5-trimethylcyclohexane; Ketone peroxide such as ethyl acetoacetate And diacyl peroxides such as benzoyl peroxide.
Among these, hydroperoxides are preferably exemplified because they can enhance the adhesiveness of the adhesive of the present invention.

  Content of (B) component in the adhesive agent of this invention is 0.5-5 mass parts normally with respect to 100 mass parts of (A) component, More preferably, it is 1-4 mass parts. When the content is less than 0.5 parts by mass, the curing rate of the adhesive is undesirably slowed. On the other hand, when the content exceeds 5 parts by mass, the physical properties such as adhesive strength are rather deteriorated.

The component (C) composed of the vanadium compound can act as a radical generation accelerator or as a redox polymerization initiator together with the component (B).
When the adhesive containing the component (A) composed of a polymerizable monomer and the component (B) composed of an organic peroxide acting as a radical initiator is brought into contact with air when cured by radical polymerization, Since the radical polymerization reaction is inhibited by the oxygen, it is difficult to cure. In particular, a large amount of air is also present on the adhesion surface of the methacrylic resin foam which can be the adherend of the adhesive of the present invention (since the adhesion surface is usually a cut surface of the foam, a large amount of air Therefore, when an adhesive is applied to the foam, the radical polymerization reaction is likely to be inhibited, and the curability is likely to deteriorate. Therefore, it is preferable that the adhesive of this invention contains (C) component which consists of vanadium compounds.
(C) As a component, vanadyl acetylacetonate, vanadium acetylacetonate, vanadyl naphthenate, etc. are used.
The content of the component (C) in the adhesive of the present invention is preferably 0.02 to 3 parts by mass, and 0.05 to 1 part by mass with respect to 100 parts by mass of the component (A). More preferred.

The component (D) composed of the acidic phosphoric acid compound can act as a storage stabilizer for the polymerizable monomer (A). Moreover, it can act also as an auxiliary agent of the redox polymerization initiator which consists of (B) component and (C) component.
As component (D), acidic phosphates such as methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, phenyl phosphate, diphenyl phosphate, mono (meth) acryloyloxyethyl phosphate, di (meth) acryloyloxyethyl phosphate; Phosphonic acids such as phenylphosphonic acid and diphenylphosphonic acid; Phosphophosphonic acids such as phenylphosphonic acid and diphenylphosphonous acid; Acid pyrophosphates such as ethyl pyrophosphate and butyl pyrophosphate; Phosphoric acid, phosphorous acid and pyrolin Phosphorus oxyacids such as acid and polyphosphoric acid are used.
The content of component (D) in the adhesive of the present invention is preferably 0.05 to 5 parts by mass and more preferably 0.2 to 3 parts by mass with respect to 100 parts by mass of component (A). preferable.

Furthermore, the adhesive of the present invention can contain an α-hydroxycarbonyl compound as an optional component. The α-hydroxycarbonyl compound can further improve the curing rate of the adhesive of the present invention.
Examples of the α-hydroxycarbonyl compound include carboxylic acid, carboxylic acid ester, ketone, aldehyde and the like having a hydroxyl group at the α carbon of the carbonyl group.
Specifically, for example, 1) α-hydroxycarboxylic acid such as lactic acid, tartaric acid, malic acid, glycolic acid, citric acid, etc. 2) α-hydroxycarboxylic acid ester such as methyl lactate, ethyl lactate, ethyl glycolate, etc. 3) Examples include α-ketols such as hydroxyacetone, dihydroxyacetone, acetoin, and benzoin, and 4) addition reaction products of α-hydroxycarboxylic acid with an epoxy compound or an oxazoline compound. These may be contained alone or in combination of two or more.
The content of the α-hydroxycarbonyl compound in the adhesive of the present invention is preferably 0.01 to 5 parts by mass, and 0.02 to 3 parts by mass with respect to 100 parts by mass of the component (A). Is more preferable.

In addition, the adhesive of the present invention can contain a component that can further improve the storage stability of the component (A) (including polymerizable (meth) acrylate), such as a radical polymerization inhibitor.
Examples of radical polymerization inhibitors include 2,6-di-t-butyl-4-methylphenol, 2,2-methylenebis (4-methyl-6-tert-butylphenol), benzoquinone, hydroquinone, methylhydroquinone, ethylenediaminetetraacetic acid 4 Sodium, oxalic acid, N-methyl-N-nitrosoaniline, N-nitrosodiphenylamine and the like can be mentioned.

Further, the adhesive of the present invention can include an organic filler. Examples of the organic filler include acrylonitrile-butadiene-styrene copolymer (ABS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), methyl methacrylate-butadiene-acrylonitrile-styrene copolymer (MBAS resin). And the like, but is not limited thereto. The said organic filler can adjust the viscosity of the adhesive agent of this invention, and can provide toughness to the hardened | cured material of an adhesive agent.
Furthermore, the adhesive of the present invention can also contain dyes, pigments and the like.

  Here, optional components (including radical polymerization inhibitors, dyes and pigments) contained in the adhesive of the present invention preferably basically use organic substances so as not to increase the amount of adhesive combustion residue. Needless to say.

The adhesive of the present invention is stored in two parts until it is used (hereinafter, these two parts are also referred to as “X agent and Y agent”). Both the two agents preferably contain the component (A), but the component (B) and the component (C) are stored so as not to coexist in separate agents (for example, organic peroxide (B ) Is contained only in the X agent, and the vanadium compound (C) is contained only in the Y agent). This is to prevent the curing reaction from starting during storage.
Moreover, although (D) component can be contained in either or both of two agents, Preferably it is contained in the same agent as (C) vanadium compound. This is because it can act as a storage stabilizer.
The composition of the polymerizable monomer of component (A) contained in agent X and the composition of the polymerizable monomer of component (A) contained in agent Y may be the same or different, but preferably the same It is.
By dividing into two agents, it is possible to store it after preparation until it is used, and it is convenient because it can be stored again after the first use.

The viscosity of the two agents (X agent and Y agent) constituting the adhesive of the present invention is preferably 50 to 20000 mPa · s, and more preferably 300 to 5000 mPa · s. The viscosity can be adjusted as appropriate by selecting the composition of the polymerizable monomer (A), blending the organic filler, and the like.
When the viscosity of the X agent or the Y agent is less than 50 mPa · s, it tends to penetrate into the adherend when it is applied to the adherend, and the adhesive strength tends to be insufficient. On the other hand, when the viscosity of the X agent or the Y agent exceeds 20000 mPa · s, it becomes difficult to uniformly apply to the coating surface of the adherend, and strong pressing after bonding tends to be required, and the curing rate tends to be slow. .

It is preferable that the solubility of the two agents (X agent and Y agent) constituting the adhesive of the present invention in a methacrylic resin foam is weak. The weak solubility means that one of the two agents (X agent or Y agent) is 0.1% on the smooth surface of the methacrylic resin foam in a constant temperature and humidity chamber at 23 ° C. and 50% RH.
The depth of the dent formed in the methacrylic resin foam when applying g / cm ² and wiping off the applied agent 10 minutes after the application is 0.2 mm or less.
Here, Kanepal AX (Kaneka Corporation; trade name) can be used as the methacrylic resin foam. “Smooth surface” means that the maximum value of the height difference of the surface is 50 μm or less when measured using a surface roughness shape measuring machine under the conditions of measurement speed = 0.3 mm / sec and measurement length = 10 mm. Say the face. Surfcom 570A (manufactured by Tokyo Seimitsu Co., Ltd.) can be used as the surface roughness shape measuring instrument. “Wipe off” means that a clean cloth or the like that can absorb the agent is used and lightly wiped by hand so as not to damage the foam.

The curing time of the adhesive of the present invention is preferably in the range of 10 seconds to 5 minutes. The curing time can be adjusted by appropriately changing the type and content of the organic peroxide (B), the vanadium compound (C), and the acidic phosphoric acid compound (D).
The curing time is about −10 ° C. to 35 ° C. The adhesive of the present invention is mixed with 0.5 g each of the X agent and the Y agent in a 2.5 ml polyethylene container, and the mixture is cured from the start of mixing. It can be measured by measuring the time until.

  The mass of the combustion residue of the cured product of the adhesive of the present invention is preferably 4% or less with respect to the mass of the cured product before combustion. The mass of the combustion residue is a cured product obtained by curing the adhesive of the present invention obtained by mixing the X agent and the Y agent (preferably by equal mass) within 23 ° C. and 50% RH constant temperature and humidity. The obtained cured product (preferably about 10 mg) is burned under the heating condition from 20 ° C. to 800 ° C. at a heating rate of 10 ° C./min in an argon atmosphere, and the mass after combustion is measured. Can be obtained.

A measurement example of the mass of the combustion residue will be specifically described.
About the hardened | cured material obtained by mixing equal mass of X agent and Y agent of the adhesive agent of this invention in a constant temperature and humidity chamber of 23 degreeC and 50% RH, it is a difference on the following conditions based on JISK7120. Perform thermal analysis and measure the weight of the combustion residue. The obtained results are shown as a residual rate (%).
Measuring instrument: Seiko Electronics Co., Ltd. TG / DTA220
Sample: Measured at 10 mg in an open sample container made of 5φ platinum Measurement temperature: 20 to 800 ° C., temperature rising speed = 10 ° C./min, measurement completed when reaching 800 ° C. Argon flow: 300 ml / min

  The amount of combustion residue is adjusted (reduced) by, for example, 1) reducing the amount of vanadium compounds and other additives that are likely to remain as combustion residues, and 2) selecting a monomer containing a large amount of oxygen atoms as component (A). )can do.

The Shore hardness D of the cured product of the adhesive of the present invention is preferably 60 or less, more preferably 50 or less. Here, the Shore hardness D is a cure obtained by curing the adhesive of the present invention obtained by mixing the X agent and the Y agent (preferably by equal mass mixing) at 23 ° C. and 50% RH constant temperature and humidity. It means the Shore hardness of the object.
The hardness can be adjusted by appropriately changing the type and content of the polymerizable (meth) acrylate or organic filler.
When the Shore hardness D exceeds 60, the cured product of the adhesive protruding from the adhesion surface after bonding may be too hard, and the adherend may be damaged when removed.

The adhesive of this invention can be manufactured by the same method as the manufacturing method of a normal two-component acrylic adhesive except mix | blending the (A)-(D) component which is an essential component. For example, it can be produced according to the following procedure.
The components (A) and (D) are charged into a stainless steel container, and while stirring, additives such as a stabilizer and a viscosity modifier are added as needed and stirred until uniform. When it is difficult to dissolve or uniformly disperse the additive, a component in which the additive is dissolved or dispersed in a component that is easily dissolved in advance is added, or the system is heated to a temperature of 80 ° C. or lower. Then (when heated, cool to 35 ° C. or lower), the component (B) is added and stirred to obtain the agent X.
Similarly, components (A) and (D) are charged into a stainless steel container, and while stirring, components (C) and additives such as stabilizers and viscosity modifiers are added as necessary, and stirred until uniform. Y agent is obtained. When it is difficult to dissolve or uniformly disperse the additive, a component in which the additive is dissolved or dispersed in a component that is easily dissolved in advance is added, or the system is heated to a temperature of 80 ° C. or lower.

  The adhesive of the present invention can adhere any adherend, but is preferably used for adhesion of a methacrylic resin foam described later. Although any method can be adopted as the bonding method, it is preferable to employ 1) a honeymoon bonding method or 2) a single-side bonding method.

1) In the honeymoon bonding method, when bonding the adherends 1 and 2, one of the two adhesives of the present invention (X agent) is applied to the adherend 1 and the mold is applied to the adherend 2 The other (Y agent) of the two agents of the model making acrylic adhesive is applied. Subsequently, the adhesive application surfaces of the adherend 1 and the adherend 2 to which the X agent and the Y agent are respectively applied are bonded together.
As a method for applying the X agent or the Y agent, a known application method such as a brush coating method, a roll coater method, or a spray method can be used.
Further, the bonded adherends 1 and 2 are pressed and / or temporarily fixed as necessary. Specifically, it is possible to use a method such as clamping with a clamp, applying a load, or pressurizing with a cold press.

2) In the single-sided bonding method, when the adherends 1 and 2 are bonded together, both of the two adhesives (X agent and Y agent) of the present invention are applied to the adherend 1. Here, the X agent and the Y agent may be applied separately, or a mixture obtained by mixing the X agent and the Y agent in advance may be applied. When X agent and Y agent are applied separately, it is preferable to apply using a trowel or brush for mixing and apply, and then mix X agent and Y agent on the application surface. Moreover, when apply | coating after mixing X agent and Y agent beforehand, it can mix using a well-known mixer and can apply | coat using a mixing iron and brush.
The adhesive applied to the adherend 1 is preferably thinly applied to the entire application surface of the adherend 1. In order to apply the adhesive thinly on the entire application surface, the applied adhesive can be extended using a brush, a bar coater or the like. Moreover, it can also apply | coat to the to-be-adhered material 1 by pressurizing and supplying X agent and Y agent to a static mixer, mixing, and spraying this liquid mixture. In this way, the step of mixing the X agent and the Y agent, the step of applying the mixture to the adherend 1 and the step of extending the mixture thinly can be completed at one time, which is the most efficient.
The adherend 1 to which the adhesive is applied is bonded to the adherend 2.
Further, the bonded adherends 1 and 2 can be pressed and / or temporarily fixed. Specifically, it is possible to use a method such as clamping with a clamp, applying a load, or pressurizing with a cold press.

<Adhesive Adhering Material of the Present Invention>
As described above, the adhesive of the present invention can be bonded to any desired one, but is particularly suitable for bonding methacrylic resin foams. That is, a preferable adherend of the adhesive of the present invention is a methacrylic resin foam (however, it is not limited thereto). Hereinafter, a methacrylic resin foam preferable as an adherend will be described.

The methacrylic resin foam which can be the adhesive material of the present invention is generally foam-molded with a methacrylic resin containing a foaming agent (hereinafter also referred to as “foamable methacrylic resin”). Can be manufactured. As a method of foam-molding the foamable methacrylic resin, any method such as a method of foaming in a mold using a heat medium such as water vapor or a method of extrusion foaming can be employed.

The foamable methacrylic resin can be produced by adding a foaming agent to the methacrylic resin (for example, impregnating the foaming agent).
As said foaming agent, a normal easily volatile foaming agent can be used. Easily volatile blowing agents include aliphatic hydrocarbons such as propane, butane and pentane, alicyclic hydrocarbons such as cyclobutane and cyclopentane, fluorinated hydrocarbons such as difluoroethane and tetrafluoroethane that have zero ozone depletion potential , And carbon dioxide. These can be used alone or in combination of two or more. The foaming agent content in the foamable methacrylic resin is preferably 3% by mass to 12% by mass.

Examples of the method of adding a foaming agent to the methacrylic resin include a method of suspending the methacrylic resin in an aqueous medium and press-impregnating the foaming agent. Alternatively, the methacrylic resin and the foaming agent may be melt mixed using an extruder. Or when manufacturing methacrylic resin by suspension polymerization, a foaming agent can also be included in methacrylic resin by adding a foaming agent during a superposition | polymerization process or the completion | finish of a superposition | polymerization process.
The expandable methacrylic resin is often produced and used in the form of particles, and is sometimes referred to as expandable methacrylic resin particles or expandable methacrylic resin beads.

As described above, the foamable methacrylic resin is a methacrylic resin containing a foaming agent. As the methacrylic resin, any methacrylic resin can be used without particular limitation.
Examples of preferable methacrylic resins include methyl methacrylate resins described in JP-A-2001-233986. That is, 1) methyl methacrylate 70 to 100% by mass, 2) monofunctional unsaturated monomer 0 to 30% by mass copolymerizable therewith, and 3) polyfunctional monomer copolymerizable therewith. A preferred example is a methyl methacrylate resin obtained by polymerizing a monomer composition composed of 2 mol% or less of vinyl group. In addition, vinyl group mol% is the unit which represented the equivalent of the functional group with%.

Examples of the copolymerizable monofunctional unsaturated monomer include, for example, 1) methacrylates such as ethyl methacrylate, propyl methacrylate, butyl methacrylate and benzyl methacrylate (excluding methyl esters), 2 ) Acrylic esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. 3) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, 4 ) Acid anhydrides such as maleic anhydride, itaconic anhydride, 5) 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, monoglycerol acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, monomethacrylate Contains hydroxyl groups such as glycerol Esters, 6) Acrylamide, methacrylamide, diacetone acrylamide, 7) Nitriles include nitriles such as acrylonitrile and methacrylonitrile, nitrogen-containing monomers such as diacetone acrylamide and dimethylaminoethyl methacrylate, 8) allyl Examples thereof include epoxy group-containing monomers such as glycidyl ether, glycidyl acrylate, and glycidyl methacrylate.
More preferred monofunctional unsaturated monomers include 1) methacrylic acid esters or 2) acrylic acid esters.

In addition, at least a part of the monofunctional unsaturated monomer is a monomer other than the above 1) to 8), for example, a vinyl aromatic hydrocarbon (for example, a styrene monomer such as styrene or α-methylstyrene). May be included). However, the content of vinyl aromatic hydrocarbon in the monomer composition is preferably 10% by mass or less. This is because the resin foam obtained from the monomer composition having a content of 10% by mass or less can sufficiently suppress the generation of combustion residues.

  Examples of the copolymerizable polyfunctional monomer include ethylene glycol such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) acrylate. Or those obtained by esterifying hydroxyl groups at both ends of the oligomer with acrylic acid or methacrylic acid; divalent alcohols such as neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate, butanediol di (meth) acrylate A hydroxyl group esterified with acrylic acid or methacrylic acid; a polyhydric alcohol such as trimethylolpropane or pentaerythritol or a polyhydric alcohol derivative thereof is esterified with acrylic acid or methacrylic acid. Ones; aryl compound having an alkenyl group such as divinylbenzene two or more thereof.

  Further, the methyl methacrylate resin preferably has a weight average molecular weight of 250,000 to 800,000 (more preferably 300,000 to 600,000).

  In a methacrylic resin foam produced by obtaining a foamable methacrylic resin from such a methacrylic resin and foam-molding it, the generation of combustion residues when burned is minimized. Therefore, by combining the foam and the adhesive of the present invention, a casting disappearance model with reduced combustion residues can be produced.

  The methacrylic resin can be obtained by polymerizing the monomer composition (preferably including methyl methacrylate, and optionally containing a monofunctional unsaturated monomer and a polyfunctional monomer). However, as a polymerization method, a well-known polymerization method for producing a general methacrylic resin can be applied. For example, suspension polymerization method, bulk polymerization method, emulsion polymerization method and the like can be mentioned. In particular, by using the suspension polymerization method, a pelletizing step for containing the foaming agent can be omitted, so that the thermal decomposition of the resin can be suppressed and the merit is great, which is preferable.

Moreover, the said polymerization can be performed using a chain transfer agent and / or a polymerization initiator as needed. As said chain transfer agent, what is used for superposition | polymerization of methyl methacrylate can be used arbitrarily. The chain transfer agent includes a monofunctional chain transfer agent having one chain transfer functional group and a polyfunctional chain transfer agent having two or more chain transfer functional groups.
Examples of the monofunctional chain transfer agent include alkyl mercaptans and thioglycolic acid esters.
Polyfunctional chain transfer agents include ethylene glycol, neopentyl glycol, trimethylol propane, ditrimethylol propane, pentaerythritol, dipentaerythritol, tripentaerythritol, sorbitol and other polyhydric alcohol hydroxyl groups such as thioglycolic acid or 3-mercapto. Those esterified with propionic acid can be mentioned.

The amount of the chain transfer agent used in the polymerization includes unsaturated monomers to be polymerized (methyl methacrylate, monofunctional unsaturated monomers copolymerizable therewith, polyfunctional unsaturated monomers, etc.). ) It is preferably 5 × 10 ⁻⁵ mol to 5 × 10 ⁻³ mol with respect to 1 mol. It is preferable to adjust the amount of the chain transfer agent within the range so that the number of functional groups of the polyfunctional monomer in the obtained polymer is 0 to 0.2 vinyl group mol%.

  The polyfunctional monomer can be a polyfunctional constituent unit (that is, a crosslinking unit) in the resulting methacrylic resin, but a polyfunctional chain transfer agent, a polyfunctional initiator, and a mixture thereof are also the same. , A polyfunctional structural unit (that is, a crosslinking unit).

<Method for Producing Mold Model of the Present Invention>
The present invention relates to a method of producing a casting disappearance model made of a methacrylic resin foam (hereinafter also referred to as “method of the present invention”). The method of the present invention is characterized by using the above-described adhesive of the present invention, but otherwise, ordinary means can be applied as appropriate. Here, the “disappearance model for casting made of methacrylic resin foam” intends a disappearance model for casting having a methacrylic resin foam as a base material.

That is, the method of the present invention includes 1) a step of preparing a plurality of model parts (including model part 1 and model part 2) constituting a disappearance model for casting made of methacrylic resin foam, and 2) the plurality of models. It includes a step of bonding parts together at their joint surfaces, and the bonding in the step 2) is performed using the adhesive of the present invention.
However, in the method of the present invention, the step 1) or 2) may be appropriately changed or may include any other step, and such methods are all included in the scope of the present invention.

  The method of the present invention is characterized in that the bonding in the step 2) is performed using the adhesive of the present invention, and the bonding is performed using a honeymoon bonding method or a single-sided coating bonding method. It is preferable that the honeymoon bonding method is used. Hereinafter, each bonding method will be described.

The honeymoon bonding method is a) a step of applying one (X agent) of the two agents of the present invention to the joint surface of one of a plurality of model parts (hereinafter, model part 1); b) A step of applying the other (Y agent) of the two adhesives of the present invention to the joint surface of another one of the plurality of model parts (hereinafter referred to as model part 2), and c) a model. The method includes a step of bonding the bonding surface of the component 1 and the bonding surface of the model component 2 together.
The application in the step a) or b) can be performed using a known application method such as a brush coating method, a roll coater method, or a spray method.

  In addition, the honeymoon bonding method may further include a step of d) pressing and / or temporarily fixing the bonded model parts 1 and 2 as necessary. The pressing and / or temporary fixing can be performed using a method such as clamping with a clamp, applying a load, or pressing with a cold press.

  The single-sided application bonding method is a) a step of applying both of the two adhesive agents (X agent and Y agent) of the present invention to the joint surface of one of a plurality of model parts (model part 1); And b) a step of bonding the joint surface of the model part 1 and the joint surface of another model part (model part 2).

The application of the X agent and the Y agent in the step a) may be performed by previously applying a mixture obtained by mixing the X agent and the Y agent to the joint surface of the model part 1. It can also be performed by separately applying to the joint surface of one of the model parts and then mixing.
When the X agent and the Y agent are applied separately and then mixed, it is preferable to apply and mix using a mixing iron or brush. Moreover, when mixing X agent and Y agent beforehand, it can mix using a well-known mixer, the iron for mixing, or a brush.

  It is preferable that the X agent and the Y agent applied in the step a) are thinly stretched over the entire bonding surface. In order to extend the X agent and the Y agent thinly over the entire joining surface, a brush, a bar coater, or the like can be used.

As a preferable mode of application in the step a), the X agent and the Y agent are pressurized and supplied to a static mixer and mixed, and this mixed solution is sprayed on the front surface of the joint surface of the model part 1 and applied. In this way, mixing of the X agent and the Y agent, application of the obtained mixed liquid, and extending the applied adhesive thinly are performed in one step, which is efficient.

  The mixed bonding method includes a step of c) pressing and / or temporarily fixing the bonded model parts 1 and 2 as necessary. The pressing and / or temporary fixing can be performed using a method such as clamping with a clamp, applying a load, or pressing with a cold press.

  According to the method of the present invention, a casting disappearance model can be manufactured in a short time and easily. In addition, the casting disappearance model manufactured by the method of the present invention has each model part strongly bonded, has little dimensional error, and further reduces combustion residue. Therefore, the casting produced by the vanishing model casting method using this vanishing model for casting has the advantage that the dimensional accuracy is high, and the strength reduction and the deterioration of workability due to adhesion and penetration of combustion residues are suppressed. .

The present invention will be described in more detail with reference to the following examples. However, these examples are illustrative only, and the scope of the present invention is not limitedly interpreted by these examples. Nor.
Adhesives in the following examples and comparative examples are composed of an X agent and a Y agent, the component (B) (organic peroxide) is included in the agent X, and the component (C) (vanadium compound) is included in the agent Y. .

Each adhesive in Examples and Comparative Examples was evaluated for the following items (1) to (4).
(1) Solubility in methacrylic resin foam of each of the X agent and Y agent constituting each adhesive (2) Set time when the methacrylic resin foam is bonded using each adhesive ( 3) Adhesive strength when methacrylic resin foam is bonded using each adhesive (4) Combustion residue value of cured product of each adhesive

Hereinafter, specific evaluation methods for (1) to (4) will be described. Here, Kanepal AX (Kaneka Corporation; trade name) was used as the methacrylic resin foam.
(1) Solubility of each of the X agent and the Y agent in the adherend In a constant temperature and humidity chamber at 23 ° C. and 50% RH, 0.1 g of the X agent or Y agent was added to the smooth (surface roughness) of the methacrylic resin foam. The maximum value of the height difference of the surface when measured using a profile measuring machine (Surfcom 570A (manufactured by Tokyo Seimitsu Co., Ltd.)) under the conditions of measurement speed = 0.3 mm / sec and measurement length = 10 mm is 50 μm. The following was applied to a square area with a surface of 1 cm ² . After 10 minutes, the applied X agent or Y agent was lightly wiped with a hand so as not to damage the foam using a clean cloth or the like capable of absorbing the agent, and the applied surface was observed. The depth at which the surface was melted and recessed was measured.

(2) Set time In a constant temperature and humidity chamber at 23 ° C. and 50% RH, an adherend 1 and an adherend 2 made of a methacrylic resin foam having dimensions of 20 × 40 × 50 mm were prepared. The X agent (0.1 g) was applied to the 20 × 40 mm surface of Adhesive 1 and the Y agent (0.1 g) was applied to the 20 × 40 mm surface of Adhesive 2 using a hand roller. One minute after the open time, the coated surfaces were bonded together (honeymoon bonding). Pressure was applied at 49 N / m ^{2 for} 3 minutes to produce an adhesive body having a length of 100 mm, a width of 40 mm, and a thickness of 20 mm.
The bending strength was measured every predetermined time (every minute) from the start of pressing, and the time when a strength of 9.8 N / cm ² or more was obtained was taken as the set time.
The bending strength was measured according to JIS K7171 at a fulcrum distance of 70 mm and a test speed of 20 mm / min.

(3) Adhesive strength In a constant temperature and humidity chamber at 23 ° C. and 50% RH, an adherend 1 and an adherend 2 made of a methacrylic resin foam having dimensions of 20 × 40 × 100 mm were prepared. The X agent (0.1 g) was applied to the 20 × 40 mm surface of the adherend 1 and the Y agent (0.1 g) was applied to the 20 × 40 mm surface of the adherent 1 using a hand roller. One minute after the open time, the coated surfaces were bonded together (honeymoon bonding). Pressure: 49 N / cm ^{2 was} pressed for 3 minutes to produce an adhesive body having a length of 100 mm, a width of 40 mm, and a thickness of 20 mm.
The bending strength was measured 24 hours after the start of pressing. The bending strength was measured according to JIS K7171 at a fulcrum distance of 70 mm and a test speed of 20 mm / min.

(4) Measurement of combustion residue value In a constant temperature and humidity chamber at 23 ° C. and 50% RH, equal amounts of X agent and Y agent constituting each adhesive were mixed and cured. 10 mg of the obtained cured product was subjected to differential thermal analysis according to the following conditions in accordance with JIS K7120, and the mass of the combustion residue was measured. The obtained result was shown by residual rate (%).

Residual rate (%) = mass of combustion residue measured (mg) / 10 mg × 100
Measuring instrument: Seiko Electronics Co., Ltd. TG / DTA220
Sample: Measured at 10 mg in an open sample container made of 5φ platinum Measurement temperature: 20 to 800 ° C., temperature rising speed = 10 ° C./min, measurement completed when reaching 800 ° C. Argon flow: 300 ml / min
[Examples 1 to 4, Comparative Example 1]
An adhesive composed of the X agent and the Y agent shown in Table 1 was prepared. The performance of each adhesive was evaluated according to the above. The results are shown in Table 1.

In Table 1 above,
1) M-600A is 2-hydroxy-3-phenoxypropyl acrylate manufactured by Kyoeisha Chemical Co., Ltd.
2) M-5300 is ω-carboxypolycaprolactone (n = 2) acrylate manufactured by Toagosei Co., Ltd.
3) M-102 is a phenoxyethylene oxide modified (n = 4) acrylate manufactured by Toagosei Co., Ltd.
4) M-90G is methoxypolyethylene glycol (n = 9) methacrylate manufactured by Shin-Nakamura Chemical Co., Ltd.
5) BPE-500 is an ethylene oxide modified (n = 10) dimethacrylate of bisphenol A manufactured by Shin-Nakamura Chemical Co., Ltd.
6) 14G is polyethylene glycol (n = 14) dimethacrylate manufactured by Shin-Nakamura Chemical Co., Ltd.

The adhesives of Examples 1 to 3 are two-component acrylic adhesives in which (A) the polymerizable monomer is composed only of polymerizable (meth) acrylates selected from polymerizable (i) to (ri). It is an agent. In the adhesive of Example 4, 90% by mass of the polymerizable monomer (A) is a polymerizable (meth) acrylate selected from (i) to (ri), and the remaining 10% by mass is , (I) to (ri) is a two-component acrylic adhesive which is methacrylic acid (molecular weight: 86).
On the other hand, in the adhesive of Comparative Example 1, 70% by mass of the polymerizable monomer (A) is a polymerizable (meth) acrylate selected from (A) to (L), and the remaining 30% by mass is , A two-component acrylic adhesive that is methacrylic acid (molecular weight: 86).

It can be seen that the adhesives of Examples 1 to 4 have 1) no solubility in the adherend, 2) a short set time, and 3) a high adhesive strength as compared with the adhesive of Comparative Example 1. . Moreover, it turns out that there is also little combustion residue like the comparative example 1. FIG.
Among the adhesives of Examples 1 to 4, the adhesives of Examples 1, 3, and 4 gave good results in terms of set time. This is presumably because the ratio of the polymerizable (meth) acrylate having a large molecular weight is higher than that of the adhesive of Example 2.

[Example 5, Comparative Examples 2 to 4]
An adhesive composed of the X agent and the Y agent shown in Table 2 was prepared. The performance of the various prepared adhesives was evaluated together with a commercially available two-component epoxy adhesive (Comparative Example 4). The epoxy adhesive of Comparative Example 4 was tested by mixing the main agent and the curing agent at 1: 1 (mass ratio). These results are shown in Table 2.

In Table 2,
7) HO-MS is 2-methacryloyloxyethyl succinate manufactured by Kyoeisha Chemical Co., Ltd.
8) GMR is glycerin dimethacrylate manufactured by NOF Corporation,
9) BPE-1300 is ethylene oxide (n = 30) modified methacrylate of bisphenol A manufactured by Shin-Nakamura Chemical Co., Ltd.
10) Two-part epoxy adhesive is available from Antico A & T US Inc. It is a fast curing type two-component epoxy adhesive manufactured by Epibond 1217-A / B.

The adhesive of Example 5 is the two-part acrylic adhesive of the present invention using vanadyl acetylacetonate as the reducing agent.
The adhesive of Comparative Example 2 or 3 is the same as the adhesive of Example 5 except that ethylenethiourea or benzoylthiourea, which is a general radical generation accelerator, is used as the reducing agent.
The adhesive of Comparative Example 4 is a commercially available two-part epoxy adhesive.

  It can be seen that the adhesive of Example 5 has a significantly shorter set time and higher adhesive strength than the adhesives of Comparative Examples 2 to 4. Further, it can be seen that the combustion residue is extremely small as compared with the adhesive of Comparative Example 4.

[Example 6]
Using the adhesive of Example 5, the set time and the adhesive strength in the single-side coating adhesion method were measured. X agent and Y agent were each applied to the adherend 1 in an amount of 0.1 g, mixed with a mixing iron, spread over the entire adhesive surface, and immediately adhered to the adherend 2. The measurement methods of the adherend dimensions, pressing, and adhesive strength were the same as in Examples 1-5. The set time was a time at which a strength of 9.8 N / cm ² or more was obtained by measuring the bending strength every predetermined time (every minute) from the start of mixing.
The set time was as short as 4 minutes and the adhesive strength was good at 26.2 N / cm ² .

  ADVANTAGE OF THE INVENTION According to this invention, the two-component acrylic adhesive for mold model manufacture with low solubility with respect to foamed acrylic resin and improved sclerosis | hardenability is provided. This adhesive can reduce the smoke and combustion residue generated when it is burned, and can accurately form a casting mold. Moreover, if the construction method provided by the present invention is used, the mold model can be manufactured in a short time.

Claims (5)

(A) a polymerizable monomer, (B) an organic peroxide, (C) a vanadium compound, and (D) an acidic phosphoric acid compound, so that the (B) and (C) do not coexist. Acrylic adhesive that is stored separately.
Manufacture disappearance model for casting made of methacrylic resin foam in which 80% by mass or more of (A) is one or more (meth) acrylates selected from the group consisting of (i) to (ri) below. A two-component acrylic adhesive.
(A) Aliphatic (meth) acrylate having a molecular weight of 125 or more (b) Carboxyl group-containing (meth) acrylate having a molecular weight of 140 or more (c) Hydroxyl group-containing (meth) acrylate having a molecular weight of 145 or more (d) Molecular weight of 230 or more Polyester (meth) acrylate (e) Phenoxyalkylene oxide-modified (meth) acrylate having a molecular weight of 210 or more (f) Alkoxyalkylene oxide-modified (meth) acrylate having a molecular weight of 450 or more (g) Bisphenol A or bisphenol having a molecular weight of 460 or more F alkylene oxide modified (meth) acrylate (h) Polyalkylene glycol modified (meth) acrylate having a molecular weight of 305 or more (i) Other (meth) acrylates having a molecular weight of 600 or more 2. The acrylic adhesive according to claim 1, wherein one of the two agents is 0.1 g / cm on a smooth surface of a methacrylic resin foam in a constant temperature and humidity chamber at 23 ° C. and 50% RH. ^2. Adhesive characterized in that the depth of the recess formed in the methacrylic resin foam when the applied agent is wiped off after 10 minutes is 0.2 mm or less.   2. The acrylic adhesive according to claim 1, wherein a mass of a combustion residue (combustion condition: 800 ° C. under an argon atmosphere) of a cured product cured in a constant temperature and humidity chamber of 23 ° C .; 50% RH is combusted. The adhesive agent characterized by being 4% or less of the mass of previous hardened | cured material. A method of manufacturing a disappearance model for casting made of methacrylic resin foam, including a step of bonding the joint surfaces of model part 1 and model part 2 constituting the disappearance model for casting made of methacrylic resin foam to each other And the step of pasting together comprises
(A) The process of apply | coating one of the two agents of the acrylic adhesive of Claim 1 to the joint surface of the model components 1,
(B) Applying the other of the two agents of the acrylic adhesive according to claim 1 to the joint surface of the model component 2, and (c) the joint surface of the model component 1 and the model component A method comprising a step of bonding the two bonding surfaces together. A method of manufacturing a disappearance model for casting made of methacrylic resin foam, including the step of bonding the joint surfaces of model part 1 and model part 2 constituting the disappearance model for casting made of methacrylic resin foam to each other And the step of pasting together comprises
(A) applying both of the two adhesives according to claim 1 to the joint surface of the model part 1; and (b) pasting the joint surface of the model part 1 and the joint surface of the model part 2 A method comprising a step of combining.