JPH0737338B2 - Aqueous sizing agent for glass fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an aqueous sizing agent for glass fibers, and more specifically,
The present invention relates to an aqueous sizing agent for glass fibers, which has a strong sizing property and can be provided with a glass fiber-reinforced thermoplastic resin which has excellent appearance and good mechanical properties without yellowing even at a high molding temperature of 200 ° C. or higher.

<Prior Art> As a use of glass fiber, there are reinforced materials of various synthetic resins, but in recent years, glass fiber reinforced thermoplastic resin (FRTP) has been attracting attention in terms of its good moldability and secondary workability. .

By the way, as for glass fiber, after melted glass is spun to form filaments, hundreds of them are bundled into one strand, which is cut into a length of 3 to 6 mm to be a chopped strand, or Further, it can be obtained by collecting dozens of them to form rovings, but prevents thread cracking and fluffing caused by friction during production of glass fibers or blending with a thermoplastic resin,
Sizes are used to protect the filaments. Therefore, the binder, which is the main component of the sizing agent, is required to have a strong sizing property for bonding and protecting the glass fiber strand.

Polyvinyl acetate is well known as such a binder, but since the resin has poor heat resistance, the molding temperature is 20%.
High as 0 ° C or higher For example, polyamide resin (6-nylon,
When it is applied to 6,6-nylon, etc., it tends to be colored by decomposition and has a drawback that the strength of the molded product is low due to its low affinity with the polyamide resin as the matrix.
Therefore, in recent years, use of a polyurethane aqueous dispersion as a binder effective when a polyamide resin is used as a matrix has been studied. Polyurethane water dispersion has high sizing property as a binder due to its excellent mechanical properties,
In addition, since the composition has a good affinity for various molding thermoplastic resins including the above polyamide-based resin, the glass fiber reinforced thermoplastic resin using this is characterized by high strength.

<Problems to be solved by the invention> However, in the conventional polyurethane water dispersion using an aromatic isocyanate, yellowing occurs during high temperature molding (molding temperature of 200 ° C or more) such as extrusion molding or injection molding, and a molded product is obtained. However, the problem that the appearance is not preferable still remains.

In order to solve such a problem, it has been attempted to use an aliphatic or alicyclic isocyanate in place of the aromatic isocyanate, but some improvement in yellowing is recognized, but particularly a light-colored molded product is still sufficiently satisfactory. At present, the appearance color tone that can be achieved is not obtained.

<Means for Solving Problems> The present inventors relate to an aqueous sizing agent for glass fibers, and particularly have excellent glass fiber sizing properties even when strengthening various thermoplastic resins having a high molding temperature of 200 ° C. or higher, and As a result of diligent research on an aqueous sizing agent for glass fibers, which does not cause yellowing at the time of high temperature molding, and has excellent appearance color tone and mechanical properties, FRTP, an isocyanate component of an alicyclic and / or aliphatic isocyanate and hydrazines, It has been found that the above-mentioned performance is satisfied by using a polyurethane water dispersion obtained by combining a chain extender of at least one compound selected from dihydrazides and semicarbazides as a binder, and completed the present invention. Came to do.

That is, the present invention relates to (A) a polyol component, (B) an alicyclic and / or aliphatic isocyanate component, and (C) at least one compound selected from hydrazines, dihydrazides, and semicarbazides. The present invention provides an aqueous sizing agent for glass fibers, which comprises, as a binder, an aqueous polyurethane dispersion obtained from the above chain extender.

As the polyol component (A) used in the production of the polyurethane aqueous dispersion, all raw materials used in ordinary polyurethane synthesis can be used. For example, a molecular weight of 200 to 10
000, preferably 300 to 5000 polyesters, polyethers, polycarbonates, polyesteramides, polyacetals, polythioethers, polybutadiene glycols and the like can be mentioned.

Representative polyesters and polyethers as the polyol component will be described in detail below. As the polyester, ethylene glycol, propylene glycol, 1,
3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (MW300-6000), dipropylene Glycol, tripropylene glycol, 1,4-cyclohexanediol, 1,
4-cyclohexanedimethanol, bisphenol A, hydroquinone and their alkylene oxide adducts,
Glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, diol or polyol components such as sorbitol and succinic acid, adipic acid,
Azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid , 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,
2-bis (phenoxy) ethane-p, p'-dicarboxylic acid,
Trimellitic acid, pyromellitic acid and anhydrides or ester-forming derivatives of these dicarboxylic acids or polycarboxylic acids; p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid and ester-forming derivatives of these hydroxycarboxylic acids In addition to the polyester obtained by a dehydration condensation reaction with an acid component such as, a polyester obtained by a ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone and a copolyester thereof.

As the polyether, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, trimethylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, glycerin,
Sorbitol, sucrose, aconitic acid, trimellitic acid,
Of compounds having at least two active hydrogen atoms such as hemimellitic acid, phosphoric acid, ethylenediamine, propylenediamine, diethylenetriamine, triisopropanolamine, pyrogallol, dihydrobenzoic acid, hydroxyphthalic acid, and 1,2,3-propanetrithiol. Examples thereof include those obtained by addition-polymerizing one or more kinds of monomers such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, cyclohexylene, etc., by a conventional method, using one or more kinds as an initiator.

It is essential that the isocyanate component (B) is an alicyclic and / or aliphatic isocyanate, such as tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 1,3-cyclopentyl. Diisocyanate, 1,3-Cyclohexylenediisocyanate, 1,4-Cyclohexylenediisocyanate, 1,3-Di (isocyanatomethyl) cyclohexane, 1,4-Di (isocyanatomethyl) cyclohexane, 4,4'-Dicyclohexylmethanediisocyanate, etc. And these trimer compounds etc. are mentioned. In order to increase the strength of the molded product, it is particularly preferable to use an alicyclic isocyanate.

Examples of the chain extender (C) include hydrazine, N,
Hydrazines such as N'-dimethylhydrazine and 1,6-hexamethylenebishydrazine; adipic acid dihydrazide,
Dihydrazides such as glutaric acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide; β-semi-carbazide propionic acid hydrazide, 3-semicarbazide-propyl-carbazic acid ester, semi-carbazide-3-semi-carbazide methyl-3,5, It is essential to use at least one compound selected from the seimicarbazides such as 5-trimethylcyclohexane. It is preferable to use hydrazines, dihydrazides, and preferably hydrazines, because they are inexpensive, easy to handle, and have excellent physical properties.

In the production of the polyurethane aqueous dispersion, in addition to the specific chain extender (C) described above, other chain extender (D) may be used depending on the case. Such chain extenders include glycols or polyols such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, hexamethylene glycol,
Examples include neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol and the like.

The polyurethane aqueous dispersion can be produced by any conventionally known method, for example, a polymer having a completed reaction or a terminal isocyanate group blocking agent (activity such as oxime, alcohol, phenol, mercaptan, ε-caprolactam, sodium bisulfite, etc.). A method of forcibly dispersing a polymer blocked with a hydrogen-containing compound) in water using an emulsifier and mechanical shearing force.

A method in which a urethane prepolymer having terminal isocyanate groups is forcibly dispersed in water by an emulsifier and mechanical shearing force, and then reacted with a chain extender in water to increase the molecular weight.

A method of imparting hydrophilicity by introducing an ionic group such as a sulfonic acid group, an amino group or a carboxyl group into a side chain or a terminal of a polyurethane polymer, and dispersing or dissolving in water by self-emulsification.

A method in which a water-soluble polyol such as polyethylene glycol or monoalkoxy polyethylene glycol is used as a polyol which is a main raw material of polyurethane and is dispersed or dissolved in water as a water-soluble polyurethane resin.

Etc. and methods combining these.

The obtained polyurethane aqueous dispersion is further a coupling agent,
Lubricants and other auxiliaries are added, and they are put to practical use as an aqueous sizing agent. Therefore, from the viewpoint of compatibility stability with these additives, the polyurethane water dispersion is preferably a polyurethane water dispersion obtained by the method (1) or (2) and having substantially nonionic property in the system. Particularly preferred is a production method capable of increasing the molecular weight of polyurethane. Specifically, the above-mentioned (A) polyol component, (B) alicyclic and / or aliphatic isocyanate component and (D) another chain extender, if necessary, are used in excess of isocyanate with respect to active hydrogen. After being made into a prepolymer having a molecular weight of 500 to 10000, preferably 800 to 5000, which has a terminal isocyanate group reacted in a ratio such that the prepolymer is forcibly emulsified and dispersed together with an emulsifier aqueous solution using mechanical shearing force. Further, (C) a chain extender of at least one compound selected from hydrazines, dihydrazides, and semicarbazides is used to carry out the chain extension reaction in water, and a molecular weight of 5,000 or more, preferably a high molecular weight of 1,000 to 100,000. This is a method of preparing an aqueous dispersion of molecular weight polyurethane.

The prepolymerization reaction in the above-mentioned method can be carried out without a solvent or in the presence of a solvent, and examples of such a solvent include acetone, methyl ethyl ketone, ketones such as cyclohexanone, ethers such as tetrahydrofuran and dioxane, ethyl acetate and the like. Examples thereof include hydrocarbons such as n-heptane, n-hexane, cyclohexane, benzene, toluene and xylene, and chlorinated hydrocarbons such as trichloroethane and dichloromethane.

As the emulsifier used for emulsifying and dispersing the above prepolymer, a commercially available emulsifier, particularly a nonionic emulsifier can be used, and examples thereof include polyoxyethylene alkyl ether, polyoxyethylene allyl ether, polyoxyethylene / polyoxypropylene glycol. Etc.

The water-based sizing agent of the present invention contains a coupling agent, a lubricant, and other auxiliaries in addition to the above-mentioned polyurethane water dispersion, and is put to practical use.

The coupling agent is a conventionally known one, for example, γ
-Glycidoxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,
N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, bis-β-hydroxy Examples thereof include organic silane compounds such as ethyl-γ-aminopropyltriethoxysilane and γ-ureidopropyltriethoxysilane. Among these, organosilane coupling agents having an amine functional group such as γ-aminopropyltriethoxysilane and N-β-aminoethyl-γ-aminopropyltriethoxysilane are preferable.

Examples of the lubricant include conventional cationic lubricants such as condensates of polyamines such as triethylenetetramine pelargonate and linear fatty acids.

In order to prepare the aqueous sizing agent of the present invention, the polyurethane water dispersion / coupling agent / lubricant is generally used as a solid content, and each of them is 1 to 20 / 0.1 to 5 / 0.01 to 5 (wt%), preferably 3 It is blended in a proportion of -10 / 0.2-2 / 0.05-1 (wt%) and put into practical use.

If necessary, the aqueous sizing agent may contain an auxiliary agent such as an antistatic agent such as an alkyl or allyl sulfonate or a sulfate of triethanolamino.

Incidentally, the water-based sizing agent for glass fibers of the present invention, within a range not impairing the effects of the present invention, a conventionally known polyvinyl acetate copolymer emulsion, an epoxy resin emulsion,
A binder such as an aqueous polyester dispersion may also be used in combination.

The aqueous sizing agent for glass fibers of the present invention comprising the above-mentioned components is applied to glass fibers according to a conventional method. For example, it can be applied by a size applicator when spinning molten glass from a bushing to make glass fiber filaments. The amount of the sizing agent attached on the glass fiber is 0.2 to 2.0% by weight based on the solid content of the glass fiber.
Is preferred.

<Effect> The aqueous sizing agent for glass fibers obtained by the present invention exhibits excellent sizing properties for glass fiber strands, and can be kneaded with a thermoplastic resin without causing yarn cracks, fuzzing or the like in chopped strands. With
When such glass fiber is applied to a thermoplastic resin that requires a molding temperature of 200 ° C. or higher, there is no decomposition of the binder during high temperature molding, no yellowing due to deterioration, and it is extremely superior to the matrix thermoplastic resin. Because of their affinity and compatibility, it has become possible to provide glass fiber reinforced thermoplastic (FRTP) molded products with extremely good appearance color and strength characteristics.

<Example> Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited thereto. However, all parts and% in the examples are by weight.

Example 1 To 574 parts of polypropylene glycol having an average molecular weight of 1000 and 26 parts of ethylene glycol, 416 parts of 4,4′-dicyclohexylmethane diisocyanate was added with stirring and reacted at 70 ° C. for 3 hours to give a prepolymer having an isocyanate content of 4.9%. Obtained. Then 40 parts per 100 parts of the above prepolymer
To a prepolymer solution obtained by adding 1 part of toluene, polyoxyethylene / polyoxypropylene glycol having a molecular weight of about 16000 (polyoxyethylene content of about 80% by weight,
Aqueous solution containing 6 parts of molecular weight 3250) of polyoxypropylene
75 parts were added and vigorously stirred with a stirrer to obtain an emulsified dispersion of the prepolymer, and then 55 parts of an aqueous solution containing 2.9 parts of 100% hydrated hydrazine was added with stirring to perform a chain extension reaction,
A polyurethane aqueous dispersion- (I) having a solid content of 40% was obtained.

Using this water dispersion (I), an aqueous sizing agent having the following composition was prepared.

Polyurethane water dispersion- (I) (solid content 40%) 10 parts γ-aminopropyltriethoxysilane 0.8〃 silazole 85A (ICI lubricant) 0.1〃 water 89.1〃 The amount of the above aqueous sizing agent attached to the glass fiber filament 0.
It was applied so as to be 5% and dried at 130 ° C. for 10 hours to prepare 6 mm chopped strands. The obtained chopped strands were mixed with 6-nylon resin pellets for general molding so that the glass fiber content was 30%, kneaded with an extruder, extruded, and cut to obtain glass fiber-containing pellets. A test piece was prepared from this pellet by an injection molding machine and its color tone was measured by a color machine (manufactured by Nippon Denshoku Industries Co., Ltd.). Judgment was made based on the color difference with non-reinforced glass fiber 6-nylon resin, and further tensile and impact tests based on ASTM-D-638 and D-256 were conducted.

Example 2 Butylene adipate polyester 476 having an average molecular weight of 2000
Parts, 1,4-butanediol 24 parts, isophorone diisocyanate 222 parts, 100% hydrated hydrazine 24.8 parts in the same manner as in Example 1 with a solid content of 40% polyurethane aqueous dispersion- (II)
After that, glass fiber reinforced 6-nylon resin test pieces were prepared in the same manner as in Example 1 and evaluated for color tone, tensile strength and impact strength.

Comparative Example 1 Glass fiber reinforced 6 in the same manner as in Example 1 using polyurethane aqueous dispersion- (III) obtained by carrying out the same reaction except that ethylenediamine was used in place of the hydrated hydrazine of Example 1. -A test piece of nylon resin was prepared and evaluated for color tone and strength.

Comparative Example 2 Polyurethane aqueous dispersion obtained by the same reaction except that tolylene diisocyanate was used in place of 4,4-dicyclohexylmethane diisocyanate of Example 1
Glass fiber reinforced with (IV) in the same manner as in Example 1.
A test piece of 6-nylon resin was prepared and evaluated for color tone and strength.

Example 3 Polycaprolactone polyol 750 having an average molecular weight of 2000
Parts, trimethylolpropane 11.2 parts, 4,4′-dicyclohexylmethane diisocyanate 208 parts and 100% hydrated hydrazine 15.0 parts to obtain a 40% solid content polyurethane aqueous dispersion- (V) in the same manner as in Example 1, Thereafter, glass fiber reinforced 6-nylon resin test pieces were prepared in the same manner as in Example 1 and evaluated for color tone, tensile strength and impact strength.

Example 4 500 parts of glycerin-based polypropylene triol having an average molecular weight of 3000, 500 parts of polypropylene glycol having an average molecular weight of 2000, 200 parts of isophorone diisocyanate, 100
% Aqueous hydrazine (20.0 parts) was used to obtain a 40% solids aqueous polyurethane dispersion (VI) in the same manner as in Example 1. Thereafter, a glass fiber reinforced 6-nylon resin test piece was prepared in the same manner as in Example 1. Was prepared and the color tone, tensile strength and impact strength were evaluated. All the results are summarized in Table 1.

Claims (1)

[Claims] 1. An (A) polyol component, (B) an alicyclic and / or aliphatic isocyanate component,
And (C) an aqueous sizing agent for glass fibers, which contains, as a binder, a polyurethane water dispersion obtained from a chain extender of at least one compound selected from hydrazines, dihydrazides, and semicarbazides.