JP2948616B2 - Reactive aqueous resin composition - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a reactive aqueous resin composition containing a carboxylic acid group-containing blocked polyurethane.

[Prior art] Polyurethane resin has a high affinity and adhesion to various kinds of base materials such as fiber, paper, wood and plastic. Therefore, aqueous polyurethane liquid is used as a fiber processing agent, paper processing agent, resin or film adhesive. Widely used for such purposes. However, the so-called polyurethane aqueous liquid, the reaction of which has been completed during the production of the aqueous liquid, has poor permeability and cannot penetrate sufficiently between the substrates (inside),
In many cases, a strong adhesive force due to the formation of a covalent bond cannot be exhibited because the compound itself has already lost reactivity. On the other hand, a reactive polyurethane aqueous liquid, a polyurethane aqueous liquid containing a so-called blocked isocyanate, retains fluidity and tackiness even after water evaporates,
It can be cast or permeated to a substrate having a relatively high hydrophobicity to adhere. In addition, some isocyanates have been put on the market because they have the characteristic that a strong bond can be formed between the isocyanate regenerated by heating and the like and the base material due to the high reactivity.

[Problems to be Solved by the Invention] However, when a fibrous base material, for example, a polyester fiber is impregnated with the above blocked isocyanate compound and cured, a so-called cushion body is obtained. , The flame retardancy is remarkably poor, and the situation is inconvenient, such as ignition → burnout, and it cannot be used for applications that require a flame retardant standard (eg, HVSS-302).

The present invention is intended to solve this problem which the conventional reactive polyurethane aqueous liquid has.

[Means for Solving the Problems] The present invention is the following invention which has been made to solve the above-mentioned problems.

Blocked polyurethane having a polyoxyethylene group and a carboxylate group, 5 to 20 parts by weight of a fatty acid ester relative to 100 parts by weight of the blocked polyurethane, and a reactive aqueous solution containing water as an essential component in which water is dissolved or dispersed therein. Resin composition.

As the fatty acid esters in the present invention, lower fatty acid esters having a boiling point of 150 ° C. or higher such as diethyl malonate, higher fatty acid esters such as methyl stearate and ethyl stearate, or higher fatty acid ester mixtures such as soybean oil, rapeseed oil and olive oil, So-called fats and oils are exemplified. Fats and oils are preferred in terms of ease of addition, price, and the like, and those in a liquid state are particularly preferred.

When the compound is in a liquid state, the compound may be added to the aqueous blocked polyurethane solution with vigorous stirring, or may be added before dissolving or dispersing the blocked polyurethane in water. When the compound is a solid, the latter method is preferable in that the compound is uniformly dispersed.

The addition amount is preferably 5 to 20 parts by weight based on 100 parts by weight of the blocked polyurethane. When the amount is less than 5 parts by weight, satisfactory flame retardancy is hardly obtained. On the other hand, when the amount exceeds 20 parts by weight, the inherent performance of the blocked polyurethane is deteriorated, which is not preferable.

The blocked polyurethane in the present invention is not particularly limited as long as it is a blocked polyurethane having a polyoxyethylene group and a carboxylic acid group. However, it is preferable that the polyoxyethylene group and the carboxylate are derived from a polyoxyalkylene polyol having them. As this polyol,
Has a high oxyethylene group content, and -CO
A carboxylic acid group-containing polyoxyalkylene polyol having an OX group (X: hydrogen atom or cation) is preferable.
Hereinafter, a blocked polyurethane obtained by using such a polyol, a raw material thereof, and the like will be described.

(1) Polyoxyalkylene polyol before carboxylic acid (salt) group introduction Polyoxyalkylene polyol is a polyoxyalkylene polyol obtained by mixing ethylene oxide or ethylene oxide with another alkylene oxide in an initiator or by sequentially reacting them. . It may be a mixture of two or more polyoxyalkylene polyols. The initiator is a compound having a hydrogen atom (a hydrogen atom of a hydroxyl group or an amino group) to which a divalent or higher valent alkylene oxide, particularly a divalent to octavalent alkylene oxide, can react.
It is a mixture of one or more initiators having a valency of at least one and initiators having a valency of at least two or more. As the initiator, a polyhydric alcohol is particularly preferred. The polyoxyalkylene polyol may be a mixture with another high molecular weight polyol which does not contain oxyethylene groups or has a small proportion thereof. Other high molecular weight polyols include polyoxyalkylene polyols having a small number of oxyethylene groups, polyether ester polyols having a small number of ester groups, polycarbonate polyols, and polyoxytetramethylene polyols.

This polyoxyalkylene polyol preferably satisfies the following conditions.

Average oxyethylene group content: 50% by weight or more is preferred. More preferably 60 to 95% by weight, particularly preferably 70 to 95% by weight.
90% by weight. Thus, it preferably contains small amounts of other oxyalkylene groups, preferably oxypropylene groups, in addition to the oxyethylene groups. If the oxyethylene group content is low, the stability of the composition of the present invention to a change in pH is reduced.

Average number of hydroxyl groups: It is preferable to exceed 2. More preferably, it is 2.3 to 8, further preferably 2.3 to 3.5, particularly preferably 2.6 to 4. If the number of hydroxyl groups is small, the curing property and adhesiveness of the polyurethane decrease.

Average molecular weight per hydroxyl group: 200 to 4000 is preferred. Preferably 300 to 3000. In the case of a low molecular weight product, a cured product of polyurethane becomes hard and brittle, and does not have toughness. With a high molecular weight material, the permeability and tackiness of the blocked polyurethane become insufficient.

(2) -COOX to the polyoxyalkylene polyol
It is preferable to introduce a -COOX group into the polyoxyalkylene polyol by introducing a group and forming a carboxylic acid (salt) group-containing polyoxyalkylene polyol by esterification or urethanation. Esterification is carried out by reacting a polycarboxylic anhydride or a reactive polycarboxylic acid derivative having a reactive carboxylic acid group and a -COOX group. Urethaneization is carried out by reacting a compound (isocyanate-reactive carboxylic acid) having an isocyanate-reactive group (hydroxyl group, primary amino group, secondary amino group, etc.) and a -COOX group with a polyisocyanate (isocyanate group of polyisocyanate). At least one of which reacts with a hydroxyl group of the polyoxyalkylene polyol, and at least one of which reacts with an isocyanate-reactive group of the -COOX group-containing compound), or-
It is carried out by reacting with a compound having a COOX group and an isocyanate group.

Examples of these carboxylic acids include maleic acid, fumaric acid, phthalic acid, malonic acid, adipic acid, trimellitic acid, butanetetracar- phonic acid, anhydrides of these polycarboxylic acids, and reactive derivatives such as acid chloride. is there. Isocyanate-reactive carboxylic acids include, for example, dimethylolpropionic acid, amino acids and the like.

X of the COOX group is a hydrogen atom or a cation, and the cation is ammonium, NR ₄ (R: at least one is a monovalent organic group such as an alkyl group and the other is a hydrogen atom), phosphonium, an alkali metal ion In particular, an alkali metal ion is preferable. Further, X of the —COOX group of the blocked polyurethane is ultimately a cation, and the —COOH group can be changed to a salt form at any stage.

Introduced into the polyoxyalkylene polyol-
The number of COOX groups is preferably such that the average is 0.005 to 0.8 per molecule of the polyoxyalkylene polyol. More preferably, the number is 0.01 to 0.6, and particularly 0.04 to 0.4. Also,
0.00 per hydroxyl group of polyoxyalkylene polyol
2-0.4, especially 0.005-0.3 is preferred. This amount is related to the stability and cure property of the blocked polyurethane to water. If the amount is too small, both the stability and the cure property will be insufficient. If the amount is too large, the cure property will be too high, and handling will be hindered. Therefore, in the introduction method for producing one —COOX group such as dicarboxylic anhydride, a compound for introducing 0.005 to 0.8 mol of —COOX group per mol of polyoxyalkylene polyol is used.

In the carboxylic acid (salt) group-containing polyoxyalkylene polyol into which a -COOX group is introduced, the average number of hydroxyl groups is preferably more than 2, more preferably 2.1
Above, especially 2.3 or more. The upper limit is 6, preferably 3.5. By having an average of less than one -COOX group per molecule, a polyoxyalkylene polyol having a larger number of -COOX groups than intended is produced,
The desired carboxylic acid (salt) group-containing polyoxyalkylene polyol can be produced by mixing with a polyoxyalkylene polyol having no group.

(3) Blocked polyurethane The blocked polyurethane in the present invention is obtained by reacting the carboxylic acid (salt) group-containing polyoxyalkylene polyol, polyisocyanate, and blocking agent. The blocked polyurethane contains about two or more blocked isocyanate groups and is substantially free of free isocyanate groups.
This polyurethane can be produced by a usual method. That is, it is obtained by reacting an isocyanate-terminated prepolymer obtained by reacting a polyol with a polyisocyanate with a blocking agent, or by reacting a partially blocked polyisocyanate with a polyol. In the former case,
The blocking agent may be used in excess, and the unreacted blocking agent may remain in the composition. Usually 1.2
Use in excess of 2.0-fold equivalent.

In the urethanization, the ratio (NCO / OH) of the hydroxyl group to the polyisocyanate group of the carboxylic acid (salt) group-containing polyoxyalkylene polyol is suitably from 1.2 to 2.5, and preferably from 1.5 to 2.0. Thus, the blocking agent is in excess,
That is, an equivalent reaction of (NCO / OH) -1 is performed. This equivalence ratio is preferably applied to either of the above two methods of the blocked polyurethane (one of the above methods may be used in excess of that). The amount of -COOX groups in the blocked polyurethane is preferably 0.02 to 3%, particularly 0.05 to 1.5% in terms of -COOH groups.

The reaction is usually performed in the absence of a solvent or a non-reactive solvent. This temperature is usually from room temperature to 160 ° C, especially from 60 to 120 ° C. Although a catalyst can be used in this reaction, the catalyst is preferably not an organometallic compound.
This is because the organometallic compound lowers the stability of the blocked polyurethane in the final aqueous composition, and tends to cause the problem of water dispersion described later. If you use a catalyst,
The catalyst is preferably an amine catalyst, particularly a tertiary amine catalyst.

When the blocked polyurethane is finally dispersed or dissolved in water, its —COOX group needs to be a carboxylate group (that is, X is a cation). When the -COOX group of the polyoxyalkylene polyol is a -COOH group,
It is necessary to change the hydrogen atom of X to a cation on the way. This conversion can be carried out in a state where the blocked polyurethane is dispersed or dissolved in water, and can be carried out at any preceding stage.

The blocked polyurethane can be dispersed or dissolved in water at any ratio. Preferably, it is 5 to 70% by weight, especially 10 to 50% by weight, of the blocked polyurethane, based on the sum of the two.
In addition, other components, for example, compounding agents such as various resins and coloring agents can be added to the composition.

(4) Polyisocyanate as Raw Material and Blocking Agent As the polyisocyanate, a polyisocyanate having an average number of functional groups per molecule of 1.8 or more, particularly 2 to 4 is preferable. Isocyanate group content is 10% or more, especially 20%
The above is preferred. As the polyisocyanate, any of so-called yellow-modified polyisocyanate and non-yellowing-modified polyisocyanate can be used, and they can be used in combination.
Preferably, a highly reactive yellowing polyisocyanate is used. Specific examples of the polyisocyanate include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), xylylene diisocyanate (XDI),
Methylene bis (cyclohexyl isocyanate) (H ₂₁ M
DI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and modified products thereof (nulated, prepolymer-modified, and carbodiimide-modified products).

As the blocking agent, various ones used as blocking agents for isocyanate groups can be used. For example, phenols, mercaptans, oximes,
There are malon diesters, acetylacetone, acetoacetic esters, lactams and the like.

Since the above-mentioned blocked product using the partially carboxylated polyol has a catalyst necessary for dissociating the blocking agent and improving the curing property in the form of a carboxylate in the molecule, this catalyst and the isocyanate residue Groups can interact efficiently in the order of molecules. Therefore, curing can be performed with a minimum amount of catalyst and mild curing conditions. In contrast, conventional catalysts are present in the aqueous phase when they are water-soluble. In the case of oil-solubility, the catalyst is added after being liquefied in water by means of emulsification or the like, but present as particles separate from the blocked product. As another method, there is a method of forcibly dispersing and dispersing an oil-soluble catalyst in an aqueous liquid of the blocked product, but the compatibility with the hydrophilic blocked product of the present invention is poor. As described above, the conventional method of adding a catalyst has low catalytic efficiency and requires an excessive amount of the catalyst, and this excess significantly reduces the thermal stability and long-term stability of the cured polyurethane resin. Therefore, in the present invention, it is preferable that substantially no organometallic catalyst is blended in the aqueous composition.

Various additives other than the catalyst can be added to the composition of the present invention. As the additives, for example, antioxidants, ultraviolet absorbers and other additives commonly used in polyurethane resins, as well as the known flame retardants, for example,
Halogen-containing phosphoric esters may be used in combination as needed. Further, other resins may be used in combination as long as the performance of the blocked polyurethane is not impaired. When a fibrous base material, for example, a polyester fiber is impregnated with a conventional aqueous polyurethane liquid and heated (120 to 130 ° C.), the polyurethane is uniformly applied to the fiber and the entire fiber is completely covered. The body is obtained. When the cushion body is subjected to a combustion test, the polyurethane ignites quickly and the propagation of fire easily occurs due to the covering state as described above,
It will burn down. On the other hand, when a fatty acid ester coexists, the effect is not always clear, but the flowability and surface properties of the resin at high temperatures are significantly improved, and the polyester fiber is partially "naked". Is obtained. When ignited, the polyester fiber melts at a high temperature, so that fire cannot propagate through the resin as described above, and it can be estimated that the polyester fiber has extremely excellent self-extinguishing properties.

The composition of the present invention is used as an adhesive or a binder, for example, an adhesive or a binder for fibers, paper, wood, plastic, or other substrates. In particular, it is useful as a binder used by applying or impregnating fibers such as polyester fibers and fibrous bodies such as polyester cotton.

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In the following, "parts" indicates parts by weight.

EXAMPLES Reference Example 1 Synthesis of Partially Carboxylated Polyol 2500 parts of polyether triol having an average molecular weight of 2500 (oxyethylene group content: 80% by weight) was added to 17.7 parts of phthalic anhydride and 3.0 parts of N, N'-dimethylbenzylamine. Add the parts
The mixture was reacted at 120 ° C. for 6 hours under a nitrogen stream to obtain a partially carboxylated polyol.

Reference Example 2 Synthesis of Blocked Aqueous Polyurethane Composition 1 Partially Carboxylated Polyol Obtained in Reference Example 1 2520.7
To this part, 438.5 parts of tolylene diisocyanate was added and reacted at 80 ° C. for 3 hours under a nitriding gas stream to obtain a urethane prepolymer having a free isocyanate group of 3.07%. Next, after cooling the prepolymer to 60 ° C, 187.9 parts of methyl ethyl ketoxime was added dropwise with stirring over 30 minutes, and the reaction was further performed at 60 ° C for 60 minutes. After confirming that the free isocyanate groups in the urethane prepolymer became 0%,
295.9 parts of olive oil were added, and the mixture was further stirred for 30 minutes. Next, an aqueous solution in which 4.8 g of sodium hydroxide was dissolved in 7068 parts of water was added with stirring, and the mixture was mixed at 30 ° C. for 30 minutes to obtain a resin component.
A 31% aqueous, slightly turbid, low viscosity blocked polyurethane aqueous solution was prepared.

Reference Example 3 An aqueous blocked polyurethane solution was prepared in the same manner as in Reference Example 2, except that the olive oil was changed to coconut oil.

Reference Example 4 An aqueous blocked polyurethane liquid was prepared in the same manner as in Reference Example 2, except that olive oil was not used.

Example 1 The aqueous solution of blocked polyurethane prepared in Reference Example 2 was impregnated with polyester fiber cotton so as to have an adhesion amount of 30%, and heat-treated at 130 ° C. for 5 minutes using a hot air generator. Further drying in an oven at 120 ° C. for 20 minutes gives a foam-like cushion body. Table 1 shows the results of a combustion test performed on this cushion body in accordance with HVSS-302.

<Example 2> The results are shown in Table 1, as in Example 1, except that Reference Example 3 was used.

<Comparative Example 1> The results are shown in Table 1, as in Example 1, except that Reference Example 4 was used.

[Effects of the Invention] The reactive water-based resin composition of the present invention has a significantly improved flame retardancy which is particularly selected for a cushion body obtained by treating a fibrous base material due to a remarkable improvement in fluidity and surface properties of the resin at high temperatures. The present invention provides a reactive aqueous resin composition to be applied.

Claims (5)

(57) [Claims] An essential component is a blocked polyurethane having a polyoxyethylene group and a carboxylate group, 5 to 20 parts by weight of a fatty acid ester per 100 parts by weight of the blocked polyurethane, and water in which these are dissolved or dispersed. Reactive aqueous resin composition. 2. The composition according to claim 1, wherein the fatty acid ester is a higher fatty acid ester alone or a mixture of two or more thereof, or a fat or oil. 3. The blocked polyurethane contains at least 50% by weight of oxyethylene groups and has -COOX groups (X:
Carboxylic acid (salt) having hydrogen atom or cation)
A reaction product of a group-containing polyoxyalkylene polyol, a polyisocyanate having an isocyanate group in a ratio of an excess equivalent to the hydroxyl group of the polyol, and a blocking agent in an amount corresponding to an excess of the polyisocyanate, The composition according to claim 1, wherein when X is a hydrogen atom, the composition is a carboxylate group-containing blocked polyurethane obtained by converting the hydrogen atom to a cation at any stage. 4. A carboxylic acid (salt) containing a carboxylic acid (salt) group-containing polyoxyalkylene polyol containing more than two hydroxyl groups per molecule on average and 0.005 to 0.8 -COOX group on average per molecule. 4. The composition according to claim 3, which is a) group-containing polyoxyalkylene polyol. 5. The polyoxyalkylene polyol containing a carboxylic acid (salt) group has an oxyethylene group content of 70 to 90% by weight, a molecular weight per hydroxyl group of 300 to 3000, and an average number of hydroxyl groups of 2.3 to 2.3.
The composition according to claim 3, which is a carboxylic acid (salt) group-containing polyoxyalkylene polyol derived from the polyoxyalkylene polyol of 3.5.