JP6263222B2 - Two-component acrylic adhesive used in the manufacture of vanishing models for casting - Google Patents

Description

  The present invention relates to a two-component acrylic adhesive used for manufacturing a casting disappearance model.

  As a casting method for castings, in addition to the conventional wood pattern method, a disappearance model casting method (also called a full mold casting method) has become widespread in recent years. The vanishing model casting method creates a vanishing model based on a synthetic resin foam, pours molten metal (molten metal) into the vanishing model embedded in the foundry sand, and burns the vanishing model to form a cavity. In this technique, a casting having the same shape as the disappearance model is obtained using the cavity as a mold. Polystyrene resin foam (Expandable PolyStyrene, abbreviated to EPS for short) is common as a synthetic resin foam that is the base material of the disappearance model, but in recent years methacrylic resin foam has also been used. It was.

When the structure is complicated, the synthetic resin foam is produced by producing a plurality of model parts made of a foam and joining the model parts together using an adhesive. This adhesive is required to have the following performance.
1) The property of dissolving the synthetic resin foam of the base material is weak.
2) The model parts can be strongly bonded at room temperature in a short time.
3) There are few combustion residues of adhesive hardened material.
4) Low odor.

  Conventionally, adhesives such as two-component epoxy, one-component urethane, and two-component urea are used as the adhesive. However, these adhesives have a weak property of dissolving the synthetic resin foam of 1) above, and the above 4) is not a problem. However, in the case of 2) above, since the curing speed is low, the adhesive strength is developed. Therefore, it takes time to leave the joined product before moving to the next step, and there is a problem that it takes time to manufacture the synthetic resin foam. For example, a two-component epoxy adhesive is excellent in adhesiveness, but since the curing reaction proceeds in an addition polymerization type, it takes time to accurately measure and mix the two components. In addition, the one-pack urethane adhesive and the two-pack urea adhesive have a slower curing rate than the epoxy adhesive, and further time is required until the adhesive strength is developed. Furthermore, the urethane-based adhesive and the urea-based adhesive have a problem that the adhesive strength is inferior.

  Further, the conventional adhesive has a drawback that a large amount of combustion residue remains with respect to 3) above. The combustion residue may enter the inside of the casting or adhere to the surface to cause casting defects. As a result, there is a problem that the strength of the casting is lowered or the workability is deteriorated.

  In contrast, polyenes such as triallyl isocyanurate, which is a polyfunctional compound having two or more carbon-carbon double bonds in one molecule, and polyfunctionality having two or more thiol groups in one molecule. A polyene / polythiol-based adhesive using a polythiol compound (Patent Document 1) and a two-component acrylic adhesive mainly composed of a polymerizable (meth) acrylate have been proposed (Patent Documents 2 and 3).

Japanese Patent No. 5405001 Japanese Patent No. 4589692 Japanese Patent No. 4681850

  The polyene / polythiol-based adhesive described in Patent Document 1 is a type in which a polythiol generates a thiyl radical in the presence of a peroxide, which is cured by a radical addition reaction with the polyene. In Patent Document 1, although triallyl isocyanurate having a nitrogen atom in the molecule as a polyene is an essential component, the proportion of the entire adhesive is less than that of the conventional adhesive, so that the combustion residue of the cured product is reduced. In addition, the property of dissolving the adherend is weak, and it has a characteristic that it can be strongly bonded in a short time. However, in the adhesive of Patent Document 1, a specific odor caused by polythiol may adversely affect the working environment.

  On the other hand, the combustion residue of the cured product of the two-component acrylic adhesive described in Patent Documents 2 and 3 is less than that of conventional adhesives, and is fast curing and rough mixing is also good. It is described that adhesiveness can be obtained. Further, it is described that the property of dissolving the synthetic resin foam of the base material is improved by examining the type and blending of the polymerizable (meth) acrylate component and the curing catalyst system. The low odor is unlikely to adversely affect the work environment.

  As described above, the two-component acrylic adhesive has excellent characteristics as compared with conventional adhesives, but the combustion residue is required to be further reduced.

  Therefore, an object of the present invention is to provide a two-component acrylic adhesive that can be used to manufacture a casting disappearance model that can further reduce combustion residues.

In order to solve the above-mentioned problems, the two-component acrylic adhesive used in the production of the disappearing model for casting according to the present invention includes a liquid A containing a polyfunctional (meth) acrylate and an organic peroxide, and a polyfunctional (meth) acrylate. And a B liquid containing a reducing agent, a two-part acrylic adhesive used for the production of a casting disappearance model, wherein 10% by weight or more of the polyfunctional (meth) acrylate is an average addition mole of alkylene oxide It is an alkylene oxide-modified di (meth) acrylate of hydrogenated bisphenol A or hydrogenated bisphenol F, the number of which is 2-12.

  According to the present invention, the combustion residue can be further reduced, the property of dissolving the synthetic resin foam of the base material is weak, the model parts can be strongly bonded at room temperature in a short time, and the odor is low. It is possible to provide a two-component acrylic adhesive used for manufacturing a casting disappearance model.

Embodiments of the present invention will be described below.
The two-component acrylic adhesive used for the production of the casting disappearance model of the present invention includes a liquid A containing a polyfunctional (meth) acrylate and an organic peroxide, a liquid B containing a polyfunctional (meth) acrylate and a reducing agent, It is a two-component acrylic adhesive used for producing a disappearance model for casting, comprising 10% by weight or more of the polyfunctional (meth) acrylate, and an alkylene oxide average addition mole number is 2 to 12. It is an alkylene oxide-modified di (meth) acrylate of hydrogenated bisphenol A or bisphenol F.

  The polyfunctional (meth) acrylate used in the liquid A and liquid B is a bifunctional or higher (meth) acrylate, and is di (meth) acrylate, tri (meth) acrylate, tetra (meth) acrylate, alkylene oxide modified di ( Mention may be made of one or more combinations of (meth) acrylate, alkylene oxide-modified tri (meth) acrylate, and alkylene oxide-modified tetra (meth) acrylate.

  As di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, tricyclodecane dimethanol di A (meth) acrylate etc. can be mentioned. Examples of the tri (meth) acrylate include pentaerythritol tri (meth) acrylate and trimethylolpropane tri (meth) acrylate. Examples of tetra (meth) acrylate include pentaerythritol tetra (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate.

  Further, as alkylene oxide-modified di (meth) acrylate, polyalkylene glycol di (meth) acrylate such as polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate Etc. Specific examples of alkylene oxide modified bisphenol A or bisphenol F di (meth) acrylate include ethylene oxide modified bisphenol A di (meth) acrylate, propylene oxide modified bisphenol A di (meth) acrylate, propylene oxide-ethylene oxide modified bisphenol A di (Meth) acrylate, ethylene oxide modified bisphenol F di (meth) acrylate, propylene oxide modified bisphenol F di (meth) acrylate, propylene oxide-ethylene oxide modified bisphenol F di (meth) acrylate, and the like.

  Examples of the alkylene oxide-modified tri (meth) acrylate include ethylene oxide-modified glycerol tri (meth) acrylate and propylene oxide-modified glycerol tri (meth) acrylate.

  Examples of the alkylene oxide-modified tetra (meth) acrylate include ethylene oxide-modified pentaerythritol tetra (meth) acrylate and propylene oxide-modified pentaerythritol tetra (meth) acrylate.

  The polyfunctional (meth) acrylate is preferably ethylene oxide modified bisphenol A di (meth) acrylate, ethylene oxide modified bisphenol F di (meth) acrylate, propylene oxide modified bisphenol A di (meth) acrylate, and propylene oxide-ethylene. It is an oxide-modified bisphenol A di (meth) acrylate.

  Furthermore, in this invention, 10 weight% or more of the polyfunctional (meth) acrylate of A liquid and B liquid, Preferably 10 weight%-50 weight%, More preferably, 10 weight%-30 weight% is hydrogenated bisphenol A. Alternatively, alkylene oxide-modified di (meth) acrylate of bisphenol F. Combustion residue can be reduced by containing 10% by weight or more of alkylene oxide-modified di (meth) acrylate of hydrogenated bisphenol A or bisphenol F. As the alkylene oxide of the alkylene oxide-modified di (meth) acrylate of hydrogenated bisphenol A or bisphenol F, the average number of moles of addition of ethylene oxide, propylene oxide, or alkylene oxide is 2 to 12, preferably 3 to 10. Specific examples of alkylene oxides of hydrogenated bisphenol A or bisphenol F alkylene oxide modified di (meth) acrylate include ethylene oxide modified hydrogenated bisphenol A diacrylate (average number of moles 4), ethylene oxide modified hydrogenated bisphenol A di And methacrylate (average number of moles added 10).

  Moreover, as an organic peroxide mix | blended in A liquid, hydroperoxides, such as t-butyl hydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, t-butyl Although peroxyesters such as peroxybenzoate, t-butyl peroxylaurate, and t-butyl peroxydecanoate can be mentioned, hydroperoxides are preferred from the viewpoint of reactivity. The compounding quantity of an organic peroxide is 1-10 weight part with respect to 100 weight part of polyfunctional (meth) acrylate, Preferably it is 2-5 weight part. If the amount is less than 1 part by weight, sufficient adhesion performance cannot be obtained. If the amount exceeds 10 parts by weight, the storage stability of the liquid A may be adversely affected, and the property of dissolving the synthetic resin foam of the base material will increase. It is not preferable.

  Moreover, B liquid contains a reducing agent, and this reducing agent forms a redox catalyst system with the organic peroxide contained in A liquid. A two-part acrylic adhesive that uses a redox catalyst system cures in a short time at room temperature and does not require strict metering of the two parts in a stoichiometric sense and is easy to handle. Has characteristics.

  Reducing agents include ethylenethiourea, trimethylthiourea, tetramethylthiourea, benzoylthiourea, thiourea compounds such as acetylthiourea, vanadium acetylacetonate, vanadylacetylacetonate, vanadium isopropoxide, vanadium pentoxide, vanadyl stearate Aromatic compounds such as cobalt compounds such as vanadium compounds such as cobalt octylate, cobalt naphthenate and cobalt acetylacetonate, N, N-dimethylaniline, N, N-dimethyl-p-toluidine and p-tolyldiethanolamine A single or a combination of two or more aldehyde-aniline reaction products such as amine, acetylphenylhydrazine, phenylhydrazine derivatives such as formylphenylhydrazine, and the reaction product of butyraldehyde and aniline. It can be used in conjunction. From the viewpoint of curing speed, a vanadium compound is preferable. The compounding quantity of a reducing agent is 0.1-5 weight part with respect to 100 weight part of polyfunctional (meth) acrylate, Preferably it is 0.5-3 weight part. If it is less than 0.1 part by weight, sufficient adhesion performance cannot be obtained, and if it exceeds 5 parts by weight, the storage stability of the B liquid is adversely affected.

  In the present invention, the following compounds may be added as necessary in order to improve the performance of the adhesive.

(Curing accelerator)
In order to improve the fast curability and adhesion, the following compounds can be added. For example, acidic phosphorus compounds such as methyl acid phosphate, ethyl acid phosphate, propyl acid phosphate, butyl acid phosphate, and methacryloyloxyethyl acid phosphate can be added to the B liquid. Further, α-hydroxycarbonyl compounds such as hydroxyacetone, dihydroxyacetone, acetoin, benzoin, glycolic acid, lactic acid, malic acid, tartaric acid, citric acid, and ethyl lactate can be added to the liquid A. A compounding quantity is 0.1-7 weight part with respect to 100 weight part of polyfunctional (meth) acrylate, respectively, Preferably it is 0.5-5 weight part.

(Polymerization inhibitor)
Moreover, the following polymerization inhibitors can also be added to A liquid and / or B liquid. For example, hydroquinone, methyl hydroquinone, t-butyl hydroquinone, hydroquinone monomethyl ether, quinhydrone, p-benzoquinone, tolquinone, naphthoquinone, 6-t-butyl-2,4-xylenol, 2,6-di-t-butyl- 4-methylphenol, 2,2′-methylenebis (4-methyl-6-tert-butylphenol) and the like can be mentioned. A compounding quantity is 0.01-3 weight part with respect to 100 weight part of polyfunctional (meth) acrylate, Preferably it is 0.05-1 weight part.

  Moreover, a pigment, a coloring agent, etc. can also be added to A liquid and / or B liquid as needed.

  The two-component acrylic adhesive of the present invention can strongly bond model parts at room temperature in a short time. For example, it can be cured in a time period of 0.5 to 3 minutes from the start of mixing of the liquid A and liquid B under a temperature condition of 5 to 35 ° C. A cured product having a Shore hardness A of 80 to 95 is obtained.

  Further, the two-component acrylic adhesive of the present invention has little combustion residue. For example, the weight of the combustion residue when the cured product is burned in a nitrogen atmosphere at 800 ° C. is 6% of the weight of the cured product before combustion. % Or less, preferably 5% or less.

  Further, the two-component acrylic adhesive of the present invention has a weak property of dissolving the synthetic resin foam. For example, a polystyrene resin foam or a methacrylic resin foam in which each of the liquid A and liquid B is an adherend is used. When applied to the surface of the substrate, substantially no change is observed on the surface of the adherend by visual observation after 1 hour at 60 ° C. Here, “substantially no change” means that a dent of 0.2 mm or more is not observed on the surface of the adherend.

  Hereinafter, the present invention will be described in more detail by way of examples. In addition, all the parts which show the usage-amount of each component show a weight part.

(1) The alkylene oxide-modified (meth) acrylate used in the liquid A and liquid B is as follows.
1-1: (Shin Nakamura Chemical Co., Ltd. ethylene oxide-modified bisphenol A diacrylate (abbreviated as A-BPE-20) (EO average addition mole number: m + n = 17)
1-2: Daiichi Kogyo Seiyaku Co., Ltd. ethylene oxide modified bisphenol A dimethacrylate (abbreviated as BPE-4) (EO average added mole number: m + n = 4)
1-3: Ethylene oxide modified diacrylate of hydrogenated bisphenol A manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (abbreviated as HBPE-4) (EO average added mole number: m + n = 4)
1-4: Ethylene oxide modified bisphenol A dimethacrylate (abbreviated as BPE-900) manufactured by Shin-Nakamura Chemical Co., Ltd. (EO average added mole number: m + n = 17)
1-5: Polyethylene glycol diacrylate (A-600) (n = 14) manufactured by Shin-Nakamura Chemical Co., Ltd.
1-6: Ethylene oxide-modified pentaerythritol tetraacrylate (abbreviated as ATM-35E) manufactured by Shin-Nakamura Chemical Co., Ltd. (EO average added mole number: l + m + n + o = 35)
1-7: Phenoxy polyethylene glycol monoacrylate (abbreviated as PHE-2D) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (n = 2)
(2) Organic peroxide used for liquid A Cumene hydroperoxide (abbreviated as CHP)
(3) Reducing agent used for liquid B 16.2 parts by weight of vanadium pentoxide was dissolved in 180 parts by weight of butyl acid phosphate by heating at 110 ° C. for 2 hours (this solution is abbreviated as VP).
(4) Others Glycolic acid (abbreviated as GA) was added to liquid A as a curing accelerator, p-benzoquinone (abbreviated as PBQ) was added to liquid A as a polymerization inhibitor, and hydroquinone (abbreviated as HQ) was added to liquid B.

  In the following examples and comparative examples, the solubility, adhesive strength, and combustion residue for the synthetic resin foam were measured under the following conditions.

<Solubility>
A polystyrene resin foam (abbreviated as EPS) and a methacrylic resin foam (abbreviated as PMMA) are used as adherends, and liquid A or liquid B is applied to the surface of the adherend at 23 ° C. Changes in the adherend after time were visually observed and evaluated according to the following criteria.
○: No change in the surface of the adherend.
X: A dent was observed on the surface of the adherend.

<Adhesive strength>
EPS and PMMA having dimensions of 20 × 40 × 50 mm were prepared. At 23 ° C., the liquid A was applied to one of the 20 × 40 mm surfaces and the liquid B was applied to the other surface, and then rubbed together. After 24 hours, a three-point bending adhesive strength test was performed according to JIS K7171 at a fulcrum distance of 70 mm and a test speed of 20 mm / min. After the test, the adhesive strength (hereinafter also referred to as adhesiveness) was evaluated according to the following criteria.
○: Material destruction rate is 60% or more ×: Material destruction rate is less than 60% Here, the material destruction rate is the ratio of the material destruction area to the adhesion area.

<Combustion residue>
The hardened | cured material was produced by mixing the equal amount of A liquid and B liquid at 23 degreeC, the differential thermal analysis was performed on the following conditions based on JISK7120, and the weight of the combustion residue was measured.
Measuring instrument: TGA-50 / 50H manufactured by Shimadzu Corporation
Sample: Measured at 10 mg in a 5φ platinum open sample container Measurement temperature: 20-800 ° C., temperature increase rate = 10 ° C./min, measurement completed at 800 ° C. Nitrogen flow: 50 ml / min

(result)
Table 1 shows the composition and evaluation results of liquid A and liquid B.

  The adhesives of Examples 1 and 2 are ethylene oxide-modified diacrylates of hydrogenated bisphenol A with respect to 90% by weight and 70% by weight of ethylene oxide-modified bisphenol A diacrylate among the polymerizable monomers of (1). (HBPE-4) is a two-component acrylic adhesive composed of 10% by weight (Example 1) and 30% by weight (Example 2). On the other hand, the adhesives of Comparative Examples 1 to 5 are 100% by weight of ethylene oxide-modified bisphenol A diacrylate (Comparative Example 1) and 70% of ethylene oxide-modified bisphenol A diacrylate among the polymerizable monomers of (1). It is a two-component acrylic adhesive composed of 30 wt% (Comparative Examples 2 to 5) of diacrylate, tetraacrylate, and monoacrylate with respect to wt%. In particular, Comparative Example 2 is an adhesive containing ethylene oxide-modified bisphenol A diacrylate (BPE-4), which is the same number of moles of ethylene oxide as HBPE-4 (m + n = 4).

  The adhesives of Examples 1 and 2 had lower solubility in the adherend than the adhesives of Comparative Examples 1 to 5, were excellent in adhesiveness, and the combustion residue was 5% or less. On the other hand, Comparative Examples 1, 2 and 4 had good solubility and adhesion, but the combustion residue exceeded 5%. Comparative Example 3 had low solubility in the adherend, but poor adhesion to EPS, and the combustion residue exceeded 5%. Further, Comparative Example 5 was highly soluble, and adhesion and combustion residue were poor.

  The adhesives of Examples 3 and 4 are blended with 30% by weight of hydrogenated bisphenol A ethylene oxide diacrylate (HBPE-4) among the polymerizable monomers of (1). On the other hand, Comparative Examples 6 and 7 are adhesives in which ethylene oxide-modified bisphenol A diacrylate (BPE-4) having the same number of moles of ethylene oxide (m + n = 4) as HBPE-4 was blended with 30% by weight of the polymerizable monomer. It is an agent. The adhesives of Examples 3 and 4 had low solubility in the adherend, excellent adhesion, and the combustion residue was 5% or less. In contrast, Comparative Examples 6 and 7 had good solubility and adhesiveness, but the combustion residue exceeded 5%.

  ADVANTAGE OF THE INVENTION According to this invention, the two-component acrylic adhesive which can be used for manufacture of the loss | disappearance model for casting with high precision can be provided.

Claims (5)

A two-component acrylic adhesive used for the production of a casting disappearance model, comprising a liquid A containing a polyfunctional (meth) acrylate and an organic peroxide and a liquid B containing a polyfunctional (meth) acrylate and a reducing agent. Because
10 weight% or more of the said polyfunctional (meth) acrylate is alkylene oxide modified di (meth) acrylate of hydrogenated bisphenol A or hydrogenated bisphenol F whose alkylene oxide average addition mole number is 2-12. Liquid acrylic adhesive.   The two-component acrylic adhesive according to claim 1, wherein the polyfunctional (meth) acrylate is selected from di (meth) acrylate, tri (meth) acrylate, and tetra (meth) acrylate.   The two-component acrylic adhesive according to claim 1 or 2, wherein the remainder of the polyfunctional (meth) acrylate is a modified alkylene oxide. 4% to 50% by weight of the polyfunctional (meth) acrylate is an alkylene oxide-modified di (meth) acrylate of hydrogenated bisphenol A or hydrogenated bisphenol F, according to any one of claims 1 to 3. Two-component acrylic adhesive.   The two-component solution according to any one of claims 1 to 4, wherein the weight of the combustion residue when the cured product is burned in a nitrogen atmosphere at 800 ° C is 6% or less of the weight of the cured product before combustion. Acrylic adhesive.