JP5021218B2 - Moisture curable urethane adhesive composition - Google Patents

Description

  The present invention relates to a moisture curable urethane adhesive composition, and more particularly, to a moisture curable urethane adhesive composition suitably used as a floor adhesive used during floor heating construction.

  Conventionally, a urethane resin composition containing a urethane prepolymer having an isocyanate group at a molecular terminal has been widely used in the industry as an adhesive, a sealant, a paint, a coating agent and the like. In this urethane resin composition, moisture in the air reacts with an isocyanate group to crosslink and cure. Therefore, it can be used as a one-component moisture-curing type, and is excellent in workability as compared with a two-component urethane resin composition in which a curing agent is blended before use.

  The urethane resin composition is also used as an adhesive for construction. Generally, this urethane adhesive composition is blended with a plasticizer, an organic solvent, etc. in order to adjust viscosity and improve workability. Has been. As the organic solvent, solvents such as toluene, xylene, ethyl acetate, and acetone are used. As the plasticizer, DOP (dioctyl phthalate), DBP (dibutyl phthalate), DOA (dioctyl adipate) and the like are used. Although they are used, these are volatile organic compounds (VOCs) and are pointed out as one of the causes of sick house problems and sick school problems. Accordingly, there has been a strong demand for urethane-based adhesives that do not contain VOC or have very little total volatile compounds (TVOC) and that have excellent adhesion and workability.

  On the other hand, in recent years, an increasing number of houses are equipped with a floor heating system in which heating wires, hot water pipes, and the like are installed on the floor. In this floor heating system, in order to prevent the heat generated by a heating wire or a hot water pipe from escaping under the floor, a method of installing a heat insulating material or the like to improve the thermal efficiency is used. As the floor heating structure, for example, a floor material is generally installed on a heat generating panel provided with a heating pipe such as a synthetic resin hot water pipe, and the floor material is improved in sound insulation and sound absorption. Therefore, a composite flooring material in which a foam, for example, a polyolefin-based foam is bonded to the back surface of a floor material such as plywood is also used. In Patent Document 1, a moisture-curing urethane-based adhesive is described as an adhesive used for bonding a heat generating panel and a flooring (see, for example, Patent Document 1).

However, in the hot water floor heating system, there is a problem that radicals are generated from the adhesive due to the heat of the heating panel of the floor heating, and the heating pipe is deteriorated. In particular, when the heating pipe is a polyethylene pipe, there is a problem that the deterioration of the polyethylene is remarkable. Furthermore, in the adhesive containing a volatile organic compound, when the floor heating hot water mat is bonded, there is a problem that the mat is melted.
JP 2002-129136 A

  The present invention provides a moisture curable urethane adhesive composition that is excellent in adhesiveness, workability, and erosion resistance and has a very low TVOC, and is suitably used as an adhesive for building materials, particularly as an adhesive for floors. Objective.

［前記式（１）中、Ｒ¹は炭素数２以上のアルキル基であり、Ｒ²はアルキル基である。］

［前記式（２）中、Ｒ³は２価の炭化水素基であり、２個のＲ⁴はそれぞれ独立してアルキル基である。］

［前記式（３）中、Ｒ⁵は３価の炭化水素基であり、３個のＲ⁶はそれぞれ独立してアルキル基である。］ In order to solve the above problems, the moisture-curable urethane adhesive composition of the present invention comprises (A) a urethane prepolymer having an active isocyanate group, and (B) a loss on heating at 125 ° C. for 3 hours is 0.1 mass. % Or less, and a ricinoleic acid derivative represented by the following formula (1), (2) or (3) is contained.

[In the formula (1), R ¹ is an alkyl group having 2 or more carbon atoms, and R ² is an alkyl group. ]

[In the formula (2), R ³ is a divalent hydrocarbon group, and the two R ⁴ are each independently an alkyl group. ]

[In the formula (3), R ⁵ is a trivalent hydrocarbon group, and three R ⁶ are each independently an alkyl group. ]

The ricinoleic acid derivative (B) is preferably glyceryl triacetyl ricinolate and / or butyl acetyl ricinolate.
It is preferable that the moisture-curable urethane adhesive composition of the present invention further contains (C) calcium carbonate. Moreover, it is preferable that the moisture hardening type urethane adhesive composition of this invention further contains the (D) hardening catalyst.

  The moisture-curable urethane adhesive composition of the present invention can be particularly suitably used as a floor adhesive.

  The construction method of the floor heating apparatus of the present invention is characterized in that the finished floor material and the floor heating panel are bonded using the moisture-curable adhesive composition of the present invention.

  The floor heating apparatus of the present invention is a floor heating apparatus formed by bonding a finished floor material and a floor heating panel using the moisture-curing adhesive composition of the present invention.

  According to the present invention, it is possible to obtain a moisture-curable urethane adhesive composition that is excellent in adhesiveness, workability, and erosion resistance and has very little TVOC. The moisture-curable adhesive composition of the present invention is suitable as an adhesive for building materials, and in particular, bonding between a finished floor material such as a single layer or composite flooring material and a base material such as a slate plate or concrete, or a finished floor. It is suitably used as an adhesive for floors used for adhesion between a material and a floor heating panel.

  Embodiments of the present invention will be described below, but these are exemplarily shown, and it goes without saying that various modifications are possible without departing from the technical idea of the present invention.

  The moisture-curing urethane adhesive composition of the present invention comprises (A) a polyisocyanate compound and / or a urethane prepolymer, and (B) a ricinoleic acid derivative whose loss on heating at 125 ° C. for 3 hours is 0.1% by mass or less. It contains.

  The urethane prepolymer (A) having an active isocyanate group used in the present invention is a polyol having two or more hydroxyl groups (OH) and a polyisocyanate compound having two or more isocyanate groups (NCO) having an excess of isocyanate groups. That is, it is obtained by reacting such that the NCO / OH equivalent ratio is greater than 1. The reaction conditions include, for example, an NCO / OH equivalent ratio of 2.0 to 15.0, more preferably 2.0 to 8.0 at a temperature of 70 to 100 ° C. in a nitrogen or dry air stream. Produced by reacting for a time. The normal NCO content of the obtained NCO-containing prepolymer is in the range of 5 to 25% by weight.

  The polyol is not particularly limited as long as it is an active hydrogen-containing compound having two or more active hydrogen groups. Generally, a polyether polyol or a polyester polyol is preferably used, and a polyether polyol is particularly preferable. is there.

  More specifically, for example, as the polyether polyol, one or two kinds of diols such as ethylene glycol, propylene glycol and butylene glycol, triols such as glycerin and trimethylolpropane, and amines such as ammonia and ethylenediamine are used. Examples include polyether polyols such as random or block copolymers obtained by ring-opening polymerization of propylene oxide and / or ethylene oxide in the presence of the above. Examples of polyester polyols include polyester polyols such as copolymers obtained by polycondensation of adipic acid, sebacic acid, terephthalic acid, etc. in the presence of ethylene glycol, propylene glycol, 1,4 butanediol, neopentyl glycol, etc. In addition, low molecular active hydrogen compounds having two or more active hydrogen groups such as bisphenol A and ramester of castor oil can be mentioned. As the above compound, those having a molecular weight of usually 100 to 7000 and 2 to 4 OH groups in one molecule can be preferably used.

  Specific examples of the polyisocyanate compound include aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), xylene diisocyanate (XDI), naphthalene diisocyanate, and hexamethylene diisocyanate (HDI). Aliphatic polyisocyanates such as lysine methyl ester diisocyanate, alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, etc. In view of the above, it is preferable to use MDI.

  The ricinoleic acid derivative (B) used in the present invention is a ricinoleic acid derivative represented by the following formula (1), (2) or (3), and the loss on heating at 125 ° C. for 3 hours is 0.1% by mass or less. It is a compound of this.

［前記式（１）中、Ｒ¹は炭素数２以上のアルキル基、好ましくは炭素数２以上１０以下のアルキル基、より好ましくはブチル基であり、Ｒ²はアルキル基、好ましくは炭素数１以上１０以下のアルキル基、より好ましくはメチル基である。］

[In the formula (1), R ¹ is an alkyl group having 2 or more carbon atoms, preferably an alkyl group having 2 to 10 carbon atoms, more preferably a butyl group, and R ² is an alkyl group, preferably 1 carbon atom. The alkyl group is 10 or more and more preferably a methyl group. ]

［前記式（２）中、Ｒ³は２価の炭化水素基、好ましくは炭素数２以上１０以上のアルキレン基であり、２個のＲ⁴はそれぞれ独立してアルキル基、好ましくは炭素数１以上１０以下のアルキル基、より好ましくはメチル基である。］

[In the formula (2), R ³ is a divalent hydrocarbon group, preferably an alkylene group having 2 or more and 10 or more carbon atoms, and the two R ⁴ groups are each independently an alkyl group, preferably 1 carbon atom. The alkyl group is 10 or more and more preferably a methyl group. ]

［前記式（３）中、Ｒ⁵は３価の炭化水素基、好ましくは炭素数３以上１０以下の３価の脂肪族炭化水素基であり、３個のＲ⁶はそれぞれ独立してアルキル基、好ましくは炭素数１以上１０以下のアルキル基、より好ましくはメチル基である。］

[In the formula (3), R ⁵ is a trivalent hydrocarbon group, preferably a trivalent aliphatic hydrocarbon group having 3 to 10 carbon atoms, and three R ⁶ are each independently an alkyl group. , Preferably an alkyl group having 1 to 10 carbon atoms, more preferably a methyl group. ]

As the ricinoleic acid derivative (B), butyl acetyl ricinolate represented by the following formula (4) or glyceryl triacetyl ricinolate represented by the following formula (5) is particularly suitable.

  The ricinoleic acid derivative (B) used in the present invention has a heat loss of 0.1% by mass or less when treated at 125 ° C. for 3 hours, and the heat loss is preferably 0.05% by mass or less, more preferably It is less than 0.01% by mass.

  The blending ratio of the ricinoleic acid derivative (B) is not particularly limited, but it is preferably 1 to 100 parts by weight, more preferably 3 to 50 parts by weight, more preferably 100 parts by weight of the urethane prepolymer (A). Preferably 5-30 mass parts is mix | blended. The ricinoleic acid derivative may be used alone or in combination of two or more.

  In the moisture curable urethane adhesive composition of the present invention, it is preferable to further add calcium carbonate (C) in order to improve workability. As the calcium carbonate, either colloidal or heavy / light calcium carbonate may be used, or surface-treated calcium carbonate may be used. In particular, from the viewpoint of economy and ease of handling, it is preferable to mix heavy calcium carbonate, and heavy calcium carbonate whose water content is adjusted to 0.3% or less is more preferable.

  The blending ratio of the calcium carbonate (C) is not particularly limited, but it is preferably 0 to 500 parts by weight, more preferably 50 to 500 parts by weight, further preferably 100 parts by weight of the urethane prepolymer (A). Is blended in an amount of 100 to 300 parts by mass. The said calcium carbonate may be used independently and may mix 2 or more types. When two or more calcium carbonates are blended, ones having different particle sizes can be blended.

It is preferable to further mix a curing catalyst (D) with the moisture curable urethane adhesive composition of the present invention. The curing catalyst (D) is a catalyst for accelerating the curing of the urethane prepolymer, and examples thereof include organometallic compounds and amines.
Examples of the organometallic compound include divalent organic tin compounds such as tin octylate and tin naphthenate; dibutyltin dioctate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin distearate, dioctyltin dilaurate, Tetravalent organic tin compounds such as dioctyltin diversate, dibutyltin oxide, dibutyltin bis (triethoxysilicate), reaction product of dibutyltin oxide and phthalate; organic acid lead salts such as lead octylate and lead naphthenate A titanate such as tetra-n-butyl titanate and tetrapropyl titanate; an organic bismuth compound such as bismuth octylate, bismuth neodecanoate and bismuth rosinate; an organic zirconium compound such as zirconium octylate; Organic cobalt compounds; organic zinc compounds; organic manganese compounds; organic iron compounds; tin-based chelate compounds such as dibutyltin bis (acetylacetonate), zirconium tetrakis (acetylacetonate), titanium tetrakis (acetylacetonate), Examples include chelate compounds of various metals such as aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), acetylacetone cobalt, acetylacetone iron, acetylacetone copper, acetylacetone magnesium, acetylacetone bismuth, acetylacetone nickel, acetylacetone zinc, and acetylacetone manganese. Of these, organic tin compounds and metal chelate compounds are preferred, and tin-based chelate compounds are more preferred because of their high reaction rate and relatively low toxicity and volatility.

  Examples of the amines include primary amines such as butylamine and octylamine, secondary amines such as dibutylamine and dioctylamine, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, diethylenetriamine, Examples include primary amines such as triethylenetetramine, tertiary amines such as triethylamine, tributylamine, triethylenediamine, and N-ethylmorpholine, or salts of these amines and carboxylic acids. .

  The blending ratio of the curing catalyst (D) is not particularly limited, but is preferably 0.01 to 10 parts by weight, and 0.01 to 5 parts by weight with respect to 100 parts by weight of the urethane prepolymer (A). It is more preferable that 0.03 to 2.5 parts by mass is further blended.

  In addition to the above-described components, the moisture curable urethane adhesive composition of the present invention includes a latent curing agent, an adhesion-imparting agent, a physical property modifier, a filler, a thixotropic agent, a dehydrating agent (storage) Stability additives), tackifiers, sagging inhibitors, UV absorbers, antioxidants, flame retardants, colorants, radical polymerization initiators, and various solvents such as alcohol.

  The moisture curable urethane adhesive composition of the present invention is excellent in adhesiveness to various adherends and is particularly suitably used as a building material adhesive. Especially, various finished floor materials such as wood, vinyl chloride resin, polyolefin resin (polyethylene, polypropylene, ethylene vinyl acetate copolymer, etc.), polyolefin resin foam (including filler-containing products such as calcium carbonate), etc. It can be applied to the adhesion between the base material (plywood, slate board, gypsum board, calcium silicate board, mortar, concrete, etc.) and the various finished flooring and the floor heating panel, but it is lined with polyolefin resin foam. It is particularly suitable as an adhesive for floors used for bonding a finished floor material such as a composite flooring material and a floor heating panel.

  The floor heating apparatus of the present invention is a floor heating apparatus formed by bonding a finished floor material and a floor heating panel using the moisture-curing adhesive composition of the present invention. It does not specifically limit as said finishing floor material, For example, the single layer or composite flooring material etc. which are prescribed | regulated by JAS timber wood- (2) are mentioned.

The construction method of the floor heating apparatus of the present invention is characterized in that the finished floor material and the floor heating panel are bonded using the moisture-curable adhesive composition of the present invention. The amount of the moisture curable adhesive composition applied to the substrate is not particularly limited, but is generally 100 to 900 g / m ^{2 in} terms of solid content, preferably 300 to 700 g / m ² . . Although it does not specifically limit as an application | coating method, Usually, a comb iron is used. The application site of the adhesive composition may be either a finished floor material or a floor heating panel. As an application method, for example, the adhesive composition of the present invention is applied to a floor heating panel, the finished floor material is bonded to the floor heating panel, and the adhesive is usually cured by moisture for 1 to 7 days to be bonded. Is completed.

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

(Synthesis Example 1)
In a stirrer equipped with a thermometer, 67.7 parts by mass of polypropylene glycol having a molecular weight of 2000 (trade name Diol-2000, manufactured by Mitsui Takeda Chemical Co., Ltd.) was dehydrated, and then 32.3 masses of 4,4-diphenylmethane diisocyanate. A urethane prepolymer A having a terminal isocyanate content of 8% by mass was obtained by reacting for 3 hours at 70 to 90 ° C. under a nitrogen stream.

(Synthesis Example 2)
In a stirrer equipped with a thermometer, after dehydrating 79.1 parts by weight of polypropylene glycol (trade name Diol-2000, manufactured by Mitsui Takeda Chemical Co., Ltd.) having a molecular weight of 2000, 20.9 parts by weight of xylylene diisocyanate was added. Then, the mixture was reacted at 70 to 90 ° C. for 3 hours under a nitrogen stream to obtain urethane prepolymer B having a terminal isocyanate content of 6% by mass.

Example 1
As shown in Table 1, 15 parts by mass of glyceryl triacetyl ricinolate (manufactured by Ito Oil Co., Ltd., trade name Rick Sizer GR-301) was added to 100 parts by mass of the urethane prepolymer A obtained in Synthesis Example 1. 150 parts by mass of calcium (product name: Whiten SB, manufactured by Shiroishi Calcium Co., Ltd.), 50 parts by mass of surface-treated calcium carbonate (product name: Shiraishi Calcium CCR-B, manufactured by Shiroishi Calcium Co., Ltd.), stabilizer (4-toluenesulfonyl isocyanate) 3 parts by weight and 0.3 parts by weight of a curing catalyst (dibutyltin dilaurate) were added and stirred and mixed at 90 ° C. under a nitrogen stream to obtain a one-part moisture-curing urethane adhesive composition.

The blending ratio of each compounding substance in Table 1 is shown in parts by mass, and * 1 to * 8 are as follows.
* 1) Urethane prepolymer A obtained in Synthesis Example 1
* 2) Urethane prepolymer B obtained in Synthesis Example 2
* 3) Glyceryl triacetylricinolate: manufactured by Ito Oil Co., Ltd., trade name Rick Sizer GR-301 (acetylated ricinoleic acid triglyceride, 125 ° C. × 3 hours heat loss less than 0.01%)
* 4) Butylacetylricinoleate: Ito Oil Co., Ltd., trade name Rick Sizer C-401 (125 ° C. × 3 hours heating loss 0.05%)
* 5) Heavy calcium carbonate: Shiraishi Calcium Co., Ltd., trade name Whiteon SB
* 6) Fatty acid surface-treated calcium carbonate: Shiraishi Calcium Co., Ltd.
* 7) Curing catalyst: dibutyltin dilaurate * 8) Stabilizer: 4-toluenesulfonyl isocyanate

  The following test was done with respect to the obtained adhesive composition. The results are shown in Table 2.

1. Adhesive test After applying the obtained adhesive composition to the slate plate defined in JIS A5430 using a comb-type iron so that the coating amount is about 550 g / m ² , a wooden flooring without backing (back side) Wood) (A) or a flooring (B) lined with an olefin-based foam was bonded to each other and allowed to stand at 23 ° C. and 55% RH for 7 days. Thereafter, the floor material was peeled off, and the adhesive strength between the slate plate and the floor material was evaluated. The evaluation criteria are as follows.
○: The floor material is destroyed by the peeling operation of the floor material.
Δ: The flooring material is destroyed by the peeling operation of the flooring material, but partly peels off even at the interface between the slate plate and the flooring material.
X: Interfacial peeling between the slate plate and the flooring material is caused by the peeling operation of the flooring material.

2. Workability test In accordance with JIS A5536, under the conditions of 23 ° C. and 5 ° C., the solderability of the joint trowel when the adhesive composition obtained as described above was applied using a standard joint trowel was evaluated. The evaluation criteria are as follows.
A: There is no sense of resistance and the handling of the comb-shaped iron is very light.
○: There is little resistance and the judgment of the comb-shaped iron is light.
Δ: There is a slight sense of resistance, and the judgment of the comb-shaped iron is felt somewhat heavy.
X: Strong sense of resistance and heavy handling of the comb-shaped iron.

3. Pipe Degradation Resistance Test A cross-linked polyethylene pipe having an inner diameter of 7 mm and a length of 10 cm was cut in half in the axial direction and punched into a dumbbell shape No. 3 (JIS K6251) to obtain a test specimen (initial test specimen).
The tensile elongation rate A of the initial specimen was measured with a tensile tester under conditions of a tensile speed of 50 mm / min. The tensile elongation was calculated by the following formula.
Tensile elongation (%) = [(length of specimen when cutting test piece−length of initial specimen) / length of initial specimen] × 100.

  Moreover, the obtained adhesive composition was uniformly applied to the surface of the central part of the initial test body and cured at 23 ° C. for 1 day or longer. Thereafter, the test specimen was left in a forced air circulation oven for 2000 hours (operating conditions of the oven: temperature 140 ° C., air replacement rate 5 times / hour). After 2000 hours, the specimen was removed from the oven and allowed to cool at 23 ° C. for 1 day. Then, the tensile elongation rate B until the said test body fractured | ruptured was measured using the tension tester on conditions with a tensile speed of 50 mm / min.

The ratio of the tensile elongation rate A and the tensile elongation rate B [(tensile elongation rate B / tensile elongation rate A) × 100] was calculated and evaluated according to the following evaluation criteria.
○: 60% or more, Δ: 50% or more and less than 60%, ×: less than 50%.

4). Erosion resistance test A test was conducted in accordance with the erosion resistance of JIS A5547, paragraph 5.8. The evaluation criteria are as follows.
○: No abnormality such as dissolution of foam is confirmed in appearance.
Δ: Erosion of the foam due to partial dissolution is confirmed.
X: Abnormalities such as dissolution are confirmed.

5. VOC test A test was conducted in accordance with JIS A1901. The total volatile organic compounds (TVOC) is ○ less than ^{200μg / m 3, 200μg / m} 3 or more 400 [mu] g / m ³ to less △, was evaluated when it exceeds 400 [mu] g / m ³ as ×.

(Examples 2 to 7)
The experiment was performed in the same manner as in Example 1 except that the compounding substances and the compounding ratios were changed as shown in Table 1. The results are shown in Table 2.

(Comparative Examples 1-6)
The experiment was performed in the same manner as in Example 1 except that the blending substances and blending ratios were changed as shown in Table 3. The results are shown in Table 4.

The blending ratio of each compounding substance in Table 3 is shown in parts by mass, * 1, * 5, * 7 and * 8 are the same as in Table 1, and * 9 and * 10 are as follows.
* 9) PPG: Product name PF716 (end-capped polypropylene glycol) manufactured by Asahi Glass Urethane Co., Ltd.
* 10) Methylacetylricinoleate: Ito Oil Co., Ltd., Rick Sizer C-101 (125 ° C. × 3 hours heat loss 0.20%)

As shown in Table 2 and Table 4, in Examples 1 to 6 using glyceryl triacetylricinoleate with a heating loss of less than 0.01% and Example 7 using butylacetylricinoleate with a heating loss of 0.05%, In addition, it had good adhesion and workability, and was excellent in deterioration resistance, erosion resistance and VOC performance of piping.

Claims (5)

(A) a urethane prepolymer having an active isocyanate group, and (B) ricinoleic acid having a weight loss of not more than 0.1% by mass at 125 ° C. for 3 hours and being glyceryl triacetyl ricinolate and / or butyl acetyl ricinolate A moisture-curing urethane adhesive composition for bonding a finished flooring and a floor heating panel, comprising a derivative.   The moisture-curable urethane adhesive composition according to claim 1, further comprising (C) calcium carbonate. (D) The moisture-curable urethane adhesive composition according to claim 1 or 2 , further comprising a curing catalyst. The construction method of the floor heating apparatus characterized by adhere | attaching a finishing floor material and a floor heating panel using the moisture hardening type adhesive composition of any one of Claims 1-3 . The floor heating apparatus which adhere | attaches a finishing floor material and a floor heating panel using the moisture hardening type adhesive composition of any one of Claims 1-3 .