Retroreflective product containing polyether polyester type polyurethane binder layer and application of retroreflective product

Abstract

The invention discloses a retroreflective product containing a polyether polyester type polyurethane binder layer and application of the retroreflective product. The retroreflective article of the present invention comprises a layer of retroreflective elements at least partially buried in an adhesive layer; the adhesive layer contains a polyurethane polymer, and the polyurethane polymer is prepared by reacting the following components: (i) special polyester polyether polyol; (ii) a polyisocyanate containing at least two isocyanate groups, the isocyanate groups being conjugated or non-conjugated bonded to an aromatic ring, or being aliphatic isocyanate. The invention provides a garment product which comprises the retroreflective product and a base material forming part of the external fabric of the garment product, and the retroreflective product is fixed on the base material. The retroreflective article using such a binder layer has excellent washing durability under harsh industrial washing conditions, the crease can be recovered, and the glass transition temperature of the retroreflective article is-30 DEG C, so that the retroreflective article can be massively used in severe cold areas.

Description

Technical Field

[0001] The invention relates to the field of adhesives, and in particular to a retroreflective product containing a polyether polyester polyurethane adhesive layer and an application thereof. Background Art

[0002] With the development of society and the advancement of science and technology, reflective products are not only used in building materials and functional items, but also in people's clothing. However, the preparation of reflective materials is generally a combination of glue and reflective material. The combination performance of reflective material and glue greatly affects the reflective beauty of reflective materials. In addition, the combination performance between glue and base fabric will also affect the washability of reflective materials and the overall user experience of customers.

[0003] There are two types of polyurethane adhesives for reflective materials in the domestic and international markets: polyester polyurethane and polyether polyurethane, but each has its own advantages and disadvantages. For example, the presence of ester bonds in polyester polyurethane can improve the adhesive force of the glue to the plant layer, but it also leads to a decrease in acid and alkali resistance and weaker elasticity than polyether polyurethane; polyether polyurethane has better acid and alkali hydrolysis resistance, but its weaker adhesion limits its wider application.

[0004] The present invention relates to a retroreflective article containing a polyurethane adhesive layer, and to a clothing article with the retroreflective article. The retroreflective article can reflect incident light back to the light source. This unique performance is conducive to the retroreflective article being widely used on clothing.

[0005] Because retroreflective articles are often used on clothing, they must be able to withstand washing conditions - otherwise, these articles will no longer provide security after repeated washings. Researchers in the field of retroreflection are aware of this problem, so they have been seeking to develop a washable retroreflective article so that retroreflective clothing can remain visible to the wearer after multiple wears and washings. Summary of the invention

[0006] In view of the deficiencies of the prior art, the present invention provides a retroreflective product containing a polyether polyester polyurethane adhesive layer and its application.

[0007] In one aspect, the present invention provides a retroreflective article comprising:

[0008] a layer of retroreflective elements at least partially embedded in the binder layer;

[0009] The adhesive layer contains a polyurethane polymer, and the polyurethane polymer is prepared by reacting the following components:

[0010] (i) Special polyester polyether polyols;

[0011] (ii) a polyisocyanate containing at least two isocyanate groups, wherein the isocyanate groups are conjugated or non-conjugated with an aromatic ring, and may also be an aliphatic isocyanate;

[0012] The special polyester polyether polyol is prepared from polyether diol and / or triol, aromatic acid and fatty acid as raw materials.

[0013] In another aspect, the present invention provides a clothing article comprising the above-mentioned retroreflective article and a substrate forming part of the outer fabric of the clothing article, wherein the retroreflective article is fixed on the substrate.

[0014] Beneficial effects of the present invention: The adhesive layer in the present application contains a polyurethane polymer made from a special polyester polyether polyol and a polyisocyanate. The polyisocyanate contains at least two isocyanate groups, which are conjugated or non-conjugated with an aromatic ring, and may also be an aliphatic isocyanate. This adhesive layer can provide a retroreflective product with excellent washability, and the creases of the provided retroreflective product can be restored. Its glass transition temperature of -30°C allows the product to be used in large quantities in cold regions. DETAILED DESCRIPTION

[0015] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in combination with the specific content of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0016] The present application provides a retroreflective product, comprising:

[0017] a layer of retroreflective elements at least partially embedded in the binder layer;

[0018] The adhesive layer contains a polyurethane polymer, which is the reaction product of a special polyester polyether polyol and a polyisocyanate, wherein the polyisocyanate contains at least two isocyanate groups, which are conjugated or non-conjugated with an aromatic ring, and may also be an aliphatic isocyanate. The polyurethane polymer contains an urethane group -NHCOO-, but may also contain other groups, such as urea groups. When a diamine chain extender is used in the reaction mixture described below, urea groups can be generated in the polymer. The special polyester polyether polyol is composed of The polyether diol and / or triol with the structure is prepared with aromatic acid and fatty acid as raw materials.

[0019] The polyurethane polymer is a thermosetting elastomer, which is prepared in the presence of an organic metal or amine catalyst, the chain extender is 1,4-butanediol, the weight ratio of the chain extender to the special polyester polyether polyol is 0.5-5, the polyurethane polymer is prepared in the presence of dibutyltin dilaurate and an organic bismuth catalyst, the reaction mixture contains an adhesion promoter, the thickness of the adhesive layer is 1-250 microns, the retroreflective element includes transparent microspheres with an average diameter of 30-200 microns, and an aluminum or silver reflective layer is arranged under the embedded part of the microspheres.

[0020] The retroreflective article retains at least 30% of its initial retroreflective brightness after completing 25 industrial laundering cycles.

[0021] The present application also provides a clothing article, which comprises the above-mentioned retroreflective article and a substrate forming part of the outer fabric of the clothing article, wherein the retroreflective article is fixed on the substrate.

[0022] Further, the polyurethane polymer is prepared by a one-step reaction of a special polyester polyether polyol, a polyisocyanate and a chain extender mixture. The one-step polymerization is carried out in a single reaction, which is contrary to the prepolymerization method including an additional step (prepolymer is formed first and then reacted with a chain extender). In order to accelerate the formation of the polymer, a catalyst can also be added to the reaction mixture.

[0023] The functionality of the special polyester polyether polyol is up to 8, but preferably 2 to 4. The special polyester polyether polyol is preferably a diol, a triol, a tetraol or a mixture thereof, and the special polyester polyether polyol can be represented by the following general formula:

[0024]

[0025] Wherein R is an aliphatic group containing 3 to 14 carbon atoms, R1 is an aliphatic or aromatic group containing 4 to 14 carbon atoms, and R2 is an aliphatic group containing up to 2 to 90 carbon atoms.

[0026] The number average molecular weight of the special polyester polyether polyol is preferably 200-20000, preferably 200-10000, and most preferably 200-5000. The acid value of the special polyester polyether polyol is preferably not greater than 1.0, and more preferably not greater than 0.7. The acid value can be measured according to ASTM D4662-93.

[0027] In one embodiment, the special polyester polyether polyol can be prepared from three reactants: aromatic acid, fatty acid and diol. The two acids are preferably used in a molar ratio of 1:1, the weight percentage of the aromatic acid is preferably about 3-36%, more preferably 6-35%, and the weight percentage of the fatty acid is preferably about 3-45%, more preferably 6-44%.

[0028] The diol is used in an amount suitable for reaction with the acid (in actual case a 20% excess) and has a chain length of 2 to 90 carbon atoms, preferably 4 to 70 carbon atoms.

[0029] Furthermore, aromatic acids can be o-phthalic acid, isophthalic acid, terephthalic acid; fatty acids are straight-chain or side-chain C4-C14 dibasic acids, aromatic dibasic acids generally contain a single aromatic ring (5-6 carbon atoms), but can also contain 2-3 aromatic rings (10 or 14 ring atoms). Aliphatic dibasic acids generally contain 4-14 carbon atoms, preferably 6-12 carbon atoms.

[0030] Further, the diol may contain about 2 to 90 carbon atoms. The general formula of the polyether diol selected is often: R and R' are the same or different (CH2)x, (OCH2)x(CH2)y, (Si(CH3)2O)x(CH2)y. x, y are integers of about 1-45. Preferred diols include polyisopropylene oxide, polybutylene oxide, polyisobutylene oxide, hydroxyl-terminated flexible epoxy resin, hydroxyl-terminated siloxane monomer, propylene glycol, hydroxyl-terminated oxidized olefins mainly polytetramethylene glycol with a molecular weight of 200-4000, polyoxypropylene (polypropylene oxide) with a molecular weight of 200-3000, polyethylene glycol with a molecular weight of 200-2000, bisphenol A, bisphenol S and mixtures thereof.

[0031] Furthermore, triols can be represented by the general formula HO[-(R(R')O-)m(-R 2 O-)n-]-H, wherein R, R' and x are as described above, R 2 represents an alkyl group containing 1 to 6 carbon atoms and having a pendant hydroxyl group, and n is 1. A preferred polyether triol is polyisopropylene oxide such as ARCOL E-2306 (MW 6000).

[0032] Furthermore, the chain extender may contain 3 to 12 carbon atoms, such as 1,6-hexanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol or cyclohexanedimethanol and amine chain extenders.

[0033] Other types of polyols are polyhydroxy flexible epoxy resins, polyhydroxy siloxane monomers, propylene glycol, glycerol, trimethylolpropane, pentaerythritol, xylitol, and sorbitol.

[0034] Further, the polyisocyanate used in the present application contains at least two isocyanate groups, which are conjugated or non-conjugated with the aromatic ring, and can also be an aliphatic isocyanate. The two isocyanate groups are preferably connected to each aromatic ring at the 1,3 position of the six-membered aromatic ring. Examples of polyisocyanates include: toluene diisocyanate (TDI), polyisocyanate (dimethyl meta-isopropenyl benzyl) ester, di(4-phenyl)methane isocyanate (MDI), polyphenylene polymethylene isocyanate (PMDI), 1,4-butane diisocyanate, isophorone diisocyanate (IPDI), etc. and mixtures thereof.

[0035] Useful chain extenders include diols and diamines, such as 1,4-butanediol, 1,6-cyclohexanedimethanol, 1,6-hexanediol, 2-methyl-1,3-propanediol, bisphenol A, and 4,4'-methylenebis(2-chloroaniline). Chain extenders may also include triols, such as glycerol, trimethylolpropane, etc. The preferred chain extender is 1,4-butanediol.

[0036] The ratio of isocyanate groups to hydroxyl groups in the reaction mixture is preferably 0.9-1.2, more preferably 1-1.1. The ratio of isocyanate groups to hydroxyl groups includes only the isocyanate groups on the polyisocyanate, but the hydroxyl groups on the special polyester polyether polyol and the chain extender are used to calculate the hydroxyl number. The weight ratio of the chain extender to the special polyester polyether polyol is about 0.5-5, more preferably 0.7-4, and most preferably 0.9-3.

[0037] Catalysts are generally used in the reaction mixture. Preferred catalysts include organotin compounds and amines, and organobismuth catalysts. Organotin compounds such as dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dithiolate, dimethyltin dimercaptoacetate and dioctyltin dimercaptoacetate. Amine catalysts are preferably tertiary amines such as triethylenediamine, B,B"-dimorpholinoethyl ether and tris(dimethylaminoethyl)phenol. The amount of catalyst in the reaction mixture is 0.05-0.30% by weight, preferably 0.06-0.20% by weight, and more preferably 0.07-0.15% by weight.

[0038] In addition to the above components, the reaction mixture may contain other additives such as adhesion promoters. Examples of adhesion promoters include isocyanate functional silanes, amine functional silanes, mercapto functional silanes and glycidyl functional silanes, vinyl functional silanes, and acrylic functional silanes.

[0039] The silane coupling agent is selected from one or more of IPTS, KH-550, KH-560, KH-570 and KH-792. Adding the silane coupling agent in the present invention can improve the adhesion of the aluminum-plated film of the reflective glass microbead machine to a certain extent.

[0040] The adhesive layer in the present application is generally a continuous, liquid-impermeable polymer sheet layer with a thickness of about 1-250 microns. Its thickness is preferably 50-150 microns. A thickness less than 50 microns may be too thin and, as a result, may not adhere to the substrate and optical element. A thickness exceeding 150 microns may unnecessarily stiffen the article and increase costs.

[0041] The present application is different from known retroreflective products in that the adhesive layer contains a polyurethane polymer made from a special polyester polyether polyol and a polyisocyanate. The polyisocyanate contains at least two isocyanate groups, which are conjugated or non-conjugated with an aromatic ring, or an aliphatic isocyanate. This adhesive layer can provide a retroreflective product with excellent washability. The present invention combines the advantages of common polyester polyurethanes and polyether polyurethanes in the market, and has substantial performance improvements over similar products currently disclosed on the market.

[0042]

[0043] Retroreflective articles treated with this adhesive retain a significant percentage of their initial retroreflectivity after repeated washings under industrial conditions. The improved washing performance may be attributed to the softness and hydrolytic stability of the adhesive layer. It is believed that these factors help to firmly fix the retroreflective elements in the adhesive layer and inhibit oxidation of the retroreflective elements when a metal reflective layer is used, as oxidized metal cannot effectively retroreflect light.

[0044] The following are examples. Unless otherwise specified, the raw materials in these examples are all commercially available.

[0045] Embodiment 1: In the esterification reaction kettle equipped with stirring device and temperature control probe, 80g terephthalic acid, 39g 3-methyl-1,5-pentanediol, 200g polytetrahydrofuran diol (weight average molecular weight is 2000), 70g adipic acid, 85g 1,6-hexanediol, 0.5g ethylene glycol antimony were added, the temperature was raised to 150°C for 20min, the temperature was raised to 200°C for 1h, the temperature was kept for 1h, the temperature was raised to 250-260°C for 1h, the temperature was kept for reaction until the system became clear and transparent completely, the water yield was calculated, and the esterification reaction was stopped when it reached more than 80%. The polycondensation reaction was started, the temperature was kept constant, the reaction was continued for a period of time, and the sampling viscosity reached 5000-8000mPa. The reaction was stopped.

[0046] Example 2: 182 g of polyol, 3 g of chain extender bis(hydroxymethyl)cyclohexane, 8 g of toluene diisocyanate, 0.2 g of organotin catalyst, and 100 g of THF were added to a closed reactor equipped with a stirring device and a temperature control device, and the temperature was raised to 85°C for polymerization. Samples were taken during the reaction to observe the wire drawing phenomenon. The infrared spectrum was 2260-2280 cm -1When the NCO peak disappears within the range, the reaction is stopped.

[0047] Example 3: In a paper cup, add 30g of polyurethane adhesive, 3g of curing agent L-75, 0.1g of sunscreen, 0.1g of silane coupling agent KH560, and 5g of ethyl acetate, stir well, apply to the plant layer or PET transfer film, and cure at 75-110°C for 5-60min to complete sample preparation.

[0048] Embodiment 4-11

[0049] Examples 4-11 were prepared as described above except that the reactants and conditions were changed as shown in Table 1. Amounts are expressed in grams.

[0050] Table 1

[0051]

[0052]

[0053] a) preparing polyester polyether polyol raw material according to the method described in Example 1;

[0054] b) preparing a polyurethane adhesive according to the method described in Example 2;

[0055] c) preparing a plant layer or PET sample according to the method described in Example 3, and then preparing a finished reflective fabric strip by hot pressing.

[0056] The samples were washed according to the industrial washing method and tested for retroreflective brightness coefficient RA according to ASTM E-810-93b. The retained retroreflective brightness % was determined as the % of the initial retroreflective brightness. The RA results are recorded in Table 2 below, and the retained retroreflective brightness (brightness retention (%)) is recorded in Table 3 below.

[0057] Table 2

[0058]

[0059]

[0060] Table 3

[0061]

[0062]

[0063] It can be seen from the data in Table 2 and Table 3 that the samples of the present invention have excellent resistance to industrial washing.

[0064] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A retroreflective product, characterized in that: include: a layer of retroreflective elements at least partially embedded in the binder layer; The adhesive layer contains a polyurethane polymer, and the polyurethane polymer is prepared by reacting the following components: (i) Special polyester polyether polyols; (ii) a polyisocyanate containing at least two isocyanate groups which are bonded conjugated or non-conjugated to an aromatic ring, or an aliphatic isocyanate; The special polyester polyether polyol is prepared from polyether diol and / or triol, aromatic acid and fatty acid as raw materials.

2. The retroreflective article according to claim 1, characterized in that The polyurethane polymer is prepared by a one-step reaction of a special polyester polyether polyol, a chain extender and polyisocyanate.

3. The retroreflective article according to claim 1 or 2, characterized in that: The special polyester polyether polyol is a product obtained by the reaction of aromatic acid, fatty acid, polyether diol and polyether triol.

4. The retroreflective article according to claim 3, characterized in that When preparing the special polyester polyether polyol, aromatic acid and fatty acid are used in a molar ratio of 1:1, and the chain length of the diol is 2-90 carbon atoms.

5. The retroreflective article according to claim 3, characterized in that: The number average molecular weight of the special polyester polyether polyol is 200-20000.

6. The retroreflective article according to claim 5, characterized in that The number average molecular weight of the special polyester polyether polyol is 200-10000.

7. The retroreflective article according to claim 6, characterized in that The number average molecular weight of the special polyester polyether polyol is 200-5000.

8. The retroreflective article according to claim 1, characterized in that The acid value of the special polyester polyether polyol is not greater than 1.

0.

9. The retroreflective article according to claim 8, characterized in that The acid value of the special polyester polyether polyol is not more than 0.7, the functionality of the special polyester polyether polyol is 2-4, and the special polyester polyether polyol is a diol, a triol, a tetraol or a mixture thereof.

10. A clothing product, characterized in that: The invention comprises the retroreflective article as claimed in claims 1 to 9 and a substrate forming part of the outer fabric of a clothing article, wherein the retroreflective article is fixed on the substrate.

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