JPH0248441A - Glass fiber-collecting agent - Google Patents

Abstract

PURPOSE:To provide the title collecting agent capable of giving molded products of high resistance to boiling and hot water, comprising (A) polyvinyl acetate and (B) blocked isocyanate. CONSTITUTION:The amount of the component A to be formulated is normally 10-90 pts.wt. of based on 100 pts.wt. of the final (objective) collecting agent. It is also preferable that the weight ratio A/B be (25:75)-(90:10). This collecting agent can readily obtained by adding a specified amount of the component B and, if needed, arbitrary additive(s) to a solution of the component A followed by mixing and agitation. Matrix resins applicable for this collecting agent are e.g., unsaturated polyester resins and epoxy resins. Having advantages mentioned above, this collecting agent will be highly usefully applied to high- strength thermosetting resin plastic bathtubs and unit bathtubs with problems of appearance.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a glass fiber sizing agent, and more specifically, it is used to strengthen thermosetting reinforced plastic bathtubs, bathtub uni-nods, etc. made of unsaturated polyester resin, epoxy resin, etc. The present invention relates to a glass fiber sizing agent useful for use in.

[Conventional technology]

Among glass fibers, long fibers are made by pulling out molten glass through a porous plate of heat-resistant metal such as platinum, forming single fibers, cooling them while stretching, and then bundling several hundred fibers into strands.

Thereafter, it is processed into roving, chopped strand, chopped strand cloak, or woven into roving cloth, glass tape, glass cloth, etc., and is used for reinforcing unsaturated polyester resin, etc.

Generally, polyvinyl acetate or polyester is used as a sizing agent for glass fibers for reinforcing unsaturated polyester resin.

Conventionally, as a result of various research and development efforts regarding glass fiber sizing agents, several proposals have been made to date.

First, Japanese Patent Publication No. 52-33237 discloses a glass fiber sizing agent using an aminoglycol-modified bisphenol type self-emulsifying polyester.

Furthermore, Japanese Patent Application Laid-Open No. 52-85595 discloses an aqueous composition for sizing glass fibers containing an epoxidized polyvinyl acetate copolymer. Furthermore, JP-A-60215
No. 557 discloses a glass fiber sizing agent using a polyurethane water body added to residual isocyanate i.

[The invention tries to solve i! Title]

However, glass fiber sizing agents using self-emulsifying polyesters have the drawback that the resulting molded products are insufficient in terms of hardness and bulk. Furthermore, in the case of an aqueous composition for glass fiber sizing that contains an epoxidized polyvinyl acetate copolymer, the polyvinyl acetate has a high water absorption rate, so the resulting molded product has a disadvantage in terms of boiling resistance. . Furthermore, in the case of a polyurethane/water dispersion, polyurethane softens the strands, resulting in poor cuttability and impregnation properties.

An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a glass fiber sizing agent that gives molded products with good boiling resistance and hot water resistance.

[Means for Solving the Problems] The glass fiber sizing agent of the present invention is characterized by comprising polyvinyl acetate (A) and blocked isocyanate (B).

The polyvinyl acetate (A) used in the present invention is not particularly limited as long as it is generally known as polyvinyl acetate. This polyvinyl acetate may be obtained by any polymerization method such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc., but it is preferably obtained by emulsion polymerization. This emulsion polymerization can be carried out by using water as a medium and dispersing the vinyl acetate monomer therein using an emulsifier.

Here, as the emulsifier, for example, g of higher alcohol is used.
There are acid salts. Furthermore, examples of the polymerization initiator include hydrogen peroxide. The resulting polymer is obtained as an emulsion,
Used as is in the present invention.

Polyvinyl acetate usually has an average molecular weight of 10,000 to 300,000. Preferably it is 20,000 to 100,000.

Note that the polyvinyl acetate may be a mixture of a monopolymer of vinyl acetate and a copolymer of vinyl acetate and an epoxy compound.

The blocked isocyanate used in the present invention is a compound in which active isocyanate groups are masked, and is a known compound. This blocked isocyanate can be easily obtained by applying various methods.

Examples are as follows. - As a method, an organic polyisocyanate which is neither aqueous solution nor water dispersible and in which 50 to 99.8%, preferably 75 to 90% of its isocyanate groups are masked by isocyanate blocks, is treated with at least one isocyanate-reactive It is obtained by reacting it with a compound containing a group and at least one phyllophilic property which renders the reaction product water-dispersible or water-soluble.

Alternatively, the blocked polyisocyanate may be prepared in a known manner by combining isocyanate blocks in which 0.2 to 50%, preferably 10 to 25% of the isocyanate groups thereof have at least one isocyanate-reactive group and at least one isocyanate-reactive group. It can also be produced by reacting an organic polyisocyanate which has been reacted with a compound containing a hydrophilic group which renders the reaction product water-dispersible.

The organic polyisocyanate used here may have, for example, a molecular weight of 600 or less and be aliphatic and/or
or di- to tetrafunctional polyisocyanates containing aliphatically bonded isocyanate groups, tris-(isocyanatohexyl)-vinyl, 1-isocyanato-3, optionally mixed with higher homologues of the polyisocyanate.
3,5-trimethyl-5-isocyanatomethylcyclohexane, a reaction product of the substance with an equivalent or less low molecular weight polyol, a trimer of the substance obtained by the isocyamelic acid formation method, and a substance exhibiting a uretadione structure. Mention may be made of dimeric, other various aliphatic, aliphatic, aromatic mono-aliphatic, aromatic or heterocyclic polyisocyanates. In addition, the blocking agent preferably has one isocyanate-reactive group and is heated to 50°C or higher, preferably 60°C or higher.
The addition reaction with the organic isocyanate takes place at a temperature of from 100 to 100°C and decomposes at a temperature of from 100 to 250°C, preferably from 140 to 200°C, releasing the blocking agent and forming an addition product back to the starting compound. Contains compounds such as Suitable blocking agents of this type include, for example, methanol, ethanol, butanol, hexanol, 2-ethylhexan-1-ol, 1-caprolactam, methyl ethyl ketone oxime, phenol.

Specific examples of this blocked isocyanate include Prominate XC-910, Prominate XC-929, and Prominate XC-950.
(The above are all trade names and are products of Takeda Pharmaceutical Company Limited).

In the glass fiber sizing agent of the present invention, polyvinyl acetate (A
) is usually blended in an amount of 10 parts by weight per 100 parts by weight of the sizing agent.
~90 parts by weight. In addition, the blending ratio (A/B) of polyvinyl acetate (A) and block isocyanate (B) is 2.
5/75 to 90/10 is preferable; if it is less than 25/75, the convergence will decrease and the cost will increase;
If it exceeds 0/10, the boiling resistance will not be sufficient. More preferably, it is 50,150 to 75/25.

The glass fiber sizing agent of the present invention may further include lubricants such as mineral oil-based, paraffin-based, fatty acid amide-based, metal soap-based, silicon-based, and surfactant-based lubricants, T-methacryloxypropyltrimethoxysilane, etc. , T-glycidoxysilane] silane coupling agents such as pyrutriethoxysilane, T-aminopropyltriethoxysilane, vinyltrichlorosilane, vinyltrichlorosilane, vinyl-tris(β-methoxyethoxy)silane, aminosilane, epoxysilane, etc. Additives may be added,
It may be used within a range that does not impair the effects of the present invention.

The glass fiber sizing agent of the present invention can be easily produced by adding a predetermined amount of blocked isocyanate and, if necessary, any additives to the polyvinyl acetate polymerization solution described above, and mixing and volatilizing the mixture.

Examples of the matrix resin to which the glass fiber sizing agent of the present invention is applied include unsaturated polyester resins and epoxy resins.

The present invention will be explained in more detail with reference to Examples and Comparative Examples below.

〔Example〕

Example 1 Vinyl acetate emulsion 7.5% by weight T-methacryloquidifurobil 1-rimethquine silane 1% by weight Lower fatty acid polyethyleneimine (lubricant) 0.3% by weight Deionized water for preparation 88.7% by weight Above concentration The agent (the present invention) was coated with an applicator on a glass filament with a diameter of 13 μm to be melt-spun.
, 500 fibers were collected and then wound onto a rotating drum.

The wound fiber bundle was dried with hot air to remove moisture, and then the 36 fiber bundles were aligned to create a roving.

On the other hand, the following compound was coated on a polyethylene film, and the above L coping was cut into 25 lengths and spread on the coated surface of A. Then, the whole was applied with a pressure roller to impregnate the glass fibers with the above compound, and the resultant sheet was subsequently wound up into a sheet and aged at 40° C. for 24 hours.

The obtained molding material was cut into a predetermined size and heated at 140°C.
Pour into a 30011 square mold heated to 5 minutes.
It was molded at a pressure of 100g/cm''.

The molded product obtained was in very good condition, with no whitening of the glass fibers, in other words, no pattern was observed at all.

Compound 3, ■Contains: Polyester (Polymer 6819, trade name, Kagoi Yakuhin Kogyo () Denso) 100 parts Calcium carbonate (Hisilite H320, trade name, manufactured by Showa Light Metal Co., Ltd.) 120 parts Zinc stearate 5 parts tert
- Butyl perbenzoate 1 part Pigment (Tona Cream, trade name, manufactured by Toyo Ink Co., Ltd.) 5 parts Magnesium oxide 1 part Polyester (Polymer 9699, trade name, manufactured by Kagoya Yakuhin Kogyo ■) 3 parts Note that the amount of sizing agent deposited is scorching hot. It is expressed as a percentage decrease (%). Also,
The following method was used to measure the wet-through and hardness of the strands.

Wet-through measurement: A strand was impregnated with a resin liquid, and the time required until a certain length of the strand was impregnated with the resin liquid was measured.

Measurement of hardness: A strand of 4630Tex was cut into 5 cm pieces and measured using the Yajiro method.

Furthermore, the boiling-resistant product was evaluated after being immersed in boiling water at 100°C.
The time required for blisters to appear when observing the surface of the molded product is shown.

The results are shown in the table.

Example 2 Vinyl acetate emulsion 5.0% by weight acrylic silane 1% by weight Lower fatty acid polyethyleneimine (lubricant) 0.5% by weight Deionized water for preparation 88.5% by weight In place of the sizing agent in Example 1, the above A molded article was obtained by the same treatment and operation as in Example 1 except that a sizing agent was used. Further, evaluation was made in the same manner as in Example 1.

The results are shown in the table.

Comparative Example 1 Vinyl acetate emulsion 5.0 fflff
i% Acrylic silane 1% by weight Lower fatty acid polyethyleneimine (lubricant) 0.5% by weight Deionized water for preparation 88.5% by weight Example 1 except that the above sizing agent was used in place of the sizing agent in Example 1 A molded article was obtained by processing and operating in the same manner as above. Further, evaluation was made in the same manner as in Example 1.

The results are shown in the table.

As is clear from the table, the hardness and wet-through properties of the strands are normal, but the boiling resistance is not sufficient.

Comparative Example 2 Vinyl acetate emulsion 7.5 m1% Polyurethane emulsion 2.5 stars% Acrylic silane 1% by weight Lower fatty acid polyethyleneimine (lubricant) 0.5% by weight Formulated state tax Ionized water 88.5% by weight Example Example 1 except that the above-mentioned sizing agent was used in place of the sizing agent.
A molded article was obtained by processing and operating in the same manner as above. Further, evaluation was made in the same manner as in Example 1. The results are shown in the table.

As is clear from the table, when a polyurethane emulsion is used instead of polyvinyl acetate and blocked isocyanate, the boiling resistance is good, but the internal strand hardness and wet-through are reduced.

(The following margin continues on the next page) Wet through: Lower is better Hardness: Higher is better [Effects of the invention] As detailed above, the glass fiber sizing agent of the present invention has boiling resistance and hot water resistance. In order to provide excellent molded products, for example, thermosetting reinforced plastic bathtubs where appearance is an issue,
It is extremely useful when applied to bathtub units, etc., and has great industrial value.

Claims (1)

[Claims] 1. Polyvinyl acetate (A) and blocked isocyanate (
B) A glass fiber sizing agent characterized by containing the following. 2. Mixing ratio of (A) and (B) above ((A)/(B)
) is from 25/75 to 90/10.